Hull Oxidation

I've gone back 3 years worth of posts but can't find the answer I'm looking for..... What causes oxidation of hulls? (don't say oxygen) I have used the 3M Heavy Oxidation and Wax product and hand rubbed my arm practically off, then waxed over that with NU Finish and it looks great........for about a week. Then the oxidation comes back and it really pisses me off. I'm thinking of A) buying a professional grinder/buffer to give the 3M product more oooph or B) taking it somewhere for professional buffing and polishing or C) having it repainted/regelcoated. It's a 1991 Nacra 5.5SL by the way. Help ME! Please?

Thanks
Greg

UV combined with oxygen breaks down the gel coat at the molecular level and once the original outer layer is gone, the gelcoat is very porous ... breaking down much easier.

"Vertglas" - buy it at West Marine (the only place I've found it online). You clean the hull, rub it down with something to remove any wax, make one quick pass with a rubbing compound (without wax) and polisher to remove the loose stuff, and then put on 6 quick coats of Vertglas with a foam/"shammy" brush. It goes on like water and dries to the touch very quickly. You could do an entire catamaran easily in an afternoon.

This stuff is a "co-polymer" (I know that's terribly generic but it's all I know) coating. It's not as hard as paint but it's much harder and durable than wax. It does wear away over time and they recommend washing the boat and applying another two coats once per year.

I refinished my 20 year old 24' monohull with this stuff last year and had several people ask me how I could afford a new boat. A year later, the sides still look terrific and the additional two coats made it shine more than I remember from last year. The topsides, however, where they get direct sun, seem to need more than the recommended two coats to get back to where they should be.

Thanks Jake,
I see why they put you on the cover. So I resign myself to a couple of coats of this co-polymer per year and people will ask me if I have a new boat!?!?!? That sounds perfect.
This also sounds like a very good reason to "invest" in one of the total boat covers (for $ 200 in Murrays) once this is completed so as to avoid some of the UV damage? Am I reading this right?

Hi Greg,

Jake is right. An invisible spectrum of ultraviolet light photo degrades just about everything on your boat; including the alum. mast, vinyl coating on the shrouds, for sure the tramp and stitching, all rubber fittings and shroud adjuster covers, etc. The gelcoat on your hulls is an especially UV sensitive plastic. I can't think of anything it doesn't degrade. It'll get your boat cover too. Oh yeah, it's what causes skin cancer and it's what we're supposed to avoid like the plague.

I haven't used Jake's product but I have used 303 Protectant for years on all my boats and outdoor gear. Lots of hardware stores carry it, as does West Marine. I know Wax is popular with sailors but it takes quite an effort to apply it, and as you know it wears off very fast, and is rapidly broken down by UV light waves, and worse yet it's hydrophilic. This means it attracts water so it'll add a small amount of weight to the boat and increase drag as you sail. 303 came out of the space program and is commercially available. It's the only thing that engineers know of that works long term, but nothing lasts forever. A note of caution, silicone, polymer sealants, and wax, all prevent the 303 from being absorbed into the gelcoat's pores and so will be ineffective. So all the stuff that doesn't work very well, will prevent the stuff that does work well, from working. It comes in a spray bottle. Spray it on the hulls and wipe the surplus off and that's it. I would put two thin coats on to begin with and do it again once or twice a season. The first couple sailings after application my hulls are super slipper. Now when I reapply it on the sides of the hull where my feet walk up and down when I'm out on the wire, I put it on with a rag that has very little 303 left in it. The first time I sailed after applying it the wind was blowing pretty good and a wave hit me not far from the beach. I went flying off the hull and around behind the stern and watched my shiney boat slowly flip.

I coat everything on my boat including the mast, block and tackle, etc. but exclude the tramp. Mine is new and slippery enough already and I use a storage cover. I also use it on my life jacket, trap harness, cat trax wheels, canoe paddles, storage bags, wet suits, dry suits, and anything neoprene just loves the stuff. Just about anything that's out in the sun a lot. It restores the original color to some extent.

I recently bought five older boats. One is a 1975, the others are 1980s and an early 1990 model. None had ever been covered, not even during winter, and all looked like they were surplus from World War II. Today with new rigging, lines, and sails, and gleaming hulls, all look like they're contemporary boats. If you have an older boat that has suffered a lot of oxidation to the hulls and not been regularly maintained, you'll probably want to use an oxidation remover first. This is because the oxidized gelcoat builds up on the surface as kind of an uneven mat and it won't produce as smooth and glossy a finish as it would, had it been removed first. West marine sells something called "Fiberglass Color Restorer for $10.00 per pint. A pint should do a whole boat. Although two of my boats required a quart apiece. What ever you choose to do, quite waxing. Good luck.

Daniel

I can say that most oxidation is caused by SMOG- Ozone is the primary component and it oxidizes paint, rubber and most things around- including lungs- that is why the American Lung Association says we need better standards to reduce asma and other problems associated with smog. I work in air quality

John R.

Quite an approptiate time to bring up this subject because up in New York, we're planning to haul the boats off the beach and tuck them away for the winter.

I've always just buffed them and waxed them, but they do look very oxidized so I'll try these products. Thanks for sharing.

W

I've gone the labor intensive route on a couple of older boats rencently:

1) Fill all the scratches with either bogged matching gel coat (visible areas) or Formula 27 (bottoms), sand smooth with 100 grit.
2) Wet sand with progressive grits - 320 (patches), 400 (everything), 600, 800, 1000.
3) 3M Heavy Duty Rubbing Compound and a machine buffer (get a real one, not the $25 toy they sell at WalMart. DeWalt 849.)
4) 3M Finesse-It II w/ machine buffer w/foam pad
5) 3M Marine Wax

I did a 17 year old Hobie 17 and a 20 year old Hobie 14 in a day or so each. They look like they were just popped out of the molds. Shiny

VERTGLAS
So if the product is so good why doesn't Rick and Mary put it in their store. I would much rather send my hard earned USD to Catamaran Sailor than west marine.... and I bet I'm not the only one

Kevin

one of these days one of you will try Vertglas and confirm what I'm telling you! It's not easy to source and would be a good product for catsailor.

OH BTW - do NOT try to use a rubbing compound on top of vertglas because it burns and turns black almost immediately. It removes easily with acetone however. I'll take a picture of my Hunter tomorrow and show the shine!

I bought a Vertiglas kit. From the MarineStore.com
I first looked through the Catsailer On-line Store but didn't see it. Googled it and the Marinestore popped right up and it was cheaper.

Promise I'll take before and after pictures and post them.

I was planning on painting my hulls this winter since it looks like no has ever waxed them. I was planning on sanding off the gel coat and applying a 2 part epoxy paint. It seems that to sand and buff and sand and buff, etc is an awful lot of work that you will have to do every year.

Am I correct in that the epoxy paint will hold the shine much longer and that it will also stand up to beach rash much better? Anyone have any expereince with this?

You don't have to do the "sand and buff" routine every year. After a few years, there'd be no gel coat left!

I did "sand and buff" my H-16 last year - a '98 - then took it to Strictly Sail Chicago and put it on display with a brand-new Tiger. People thought the 16 was newer than the Tiger. It still looks that way today, although it did pick up a few scratches over the summer (9 2-day regattas and 7,250 miles on the trailer )

Paint no matter what kind isn't going to stand up to the beach. I painted a Hobie 18 I used to have with Imron and before I did I taped off about a four inch wide strip tapered down at the front and left that gelcoat. The Gelcoat is much easier to repair and work with. If your going to sand anyway you might as well try sanding and polishing first.

Another way to do this would be to sand to about 280 and have the boat clearcoated with Imron or Awlgrip. This works really good on colored hulls. Nice thing is if get it scratched the old color dosen't show through.

Last summer we bought an older J22 for racing and worked on it over the winter. We decided to refinish the entire hull and refair it. But, we made a mistake in having the boat repainted instead of working with the Gelcoat that was there. The paint does chip and cannot be "brought back to life". I'm sorry we did it. I've seen catamarans painted and they look good from far, but the finish is less than acceptable. I've always done better with the rubbing and buffing.

I'm going to try that new procuct on the 2 Hobie Cats in my life. I certainly would never paint them.

Wyatt

Hey Bullswan,

You're heading in the right direction. I don't think Vertglas is a panacea, but you're light years ahead of the guys who believe in painting to restore faded hulls. Vertglas claims that it makes your gelcoat completely impervious to UV degredation. That's not accurate. It doesn't. But it should, if correctly applied, do an acceptable job of protecting your hulls for the bulk of the sailing season. Ant that's really all that matters.

Wyatt, I'm with you. Once you do something that doesn't work very well, why keep on doing it? Hobienick, Catman, and all you guys who believe paint is the answer, I don't want to dissuade you from painting if your heart is set in that direction. But all you're doing is covering up old oxidized damage and doing nothing to prevent it from happening to your new paint job. Some paints are better than others, that's true, and will resist breakdown by the sun better than others. But they all deteriorate after a relatively short period of time.

If your hulls are damaged by deep scratches or cracks then you've got a repair job to do on the gelcoat. Other than these specific areas I would never sand the gelcoat. It's there for a purpose.

Calcheck I hate to disagree with you, but if we could prevent UV damage; the amount of damage from ozone wouldn't be enough to prompt anybody to correct it. Guys think about it for a minute. Why is it that every car ever owned, always faded if parked outside for a period of time. In fact UV penetrates inside the car and the dash, seats, door panel, etc. all fad too. My living room carpet is faded in the area that the sun reaches. So what is it that causes this fading? It isn't ozone. It's UV light. It causes oxidation on a molecular level.

If you want to protect your hulls, tramp, lines, etc. then the boat must be covered when not in use. Period!!!! If you want your boat protected when you're out on the water, an area of intense UV light, then you have to cover everthing with a protectorant. It sounds like most of you have boats that are pretty degraded, so you would be well advised to pony up seventy bucks for the Vertglass restoration kit. If your boat isn't too badly oxidized, you should be able to get buy with Vertglas Sealer for twenty seven to fifty bucks. I'd rather spend ten bucks for a little bottle of 303 Protectant and wipe the hulls down every couple of months. I suppose it takes me the better part of ten minutes. The friction caused by the water moving over the hulls, will over time, remove the surface coating of both 303 Protectant and Vertglass. The thirty or forty minutes a year I spend doing maintenance, saves me from the hours and hours of hard grunt work guys have to do when their boat has bad hull damage.

Prindle 16, it takes a fair amount of sales to justify stocking a product. Looking at all the cats I run into it, seems to me there isn't much of a market to justify stocking this stuff. We still have lots of guys who believe waxing is doing something good for their boat. Overall looks to me like most guys don't do anything to take care of their boats.

In a way this thread is a bit of an irony for me because I'm more interested in taking care of the hulls from the water line down. I wouldn't ever set my hulls on anything but my little foam rests.

Daniel

You're getting a DNF if I have to pull out the dictionary again.

Damn, I was going to say there appears to be a plethora of ideas on how to solve the dilemma.. but I guess I won't.
Don't want a DNF. I also can't say I'm autodidactic either.
Thanks
Greg

Greg,

Anybody who knows what an autdidact is must be one

Daniel

Jake,





Daniel

Not even automotive painters use a buffer anymore the oil base compounds are toxic. The modern method is to wet sand with 1200 paper and 2000 grit(yes2000grit with lots of water) this gives you great control without removing too much gellcoat. After sanding wipe on a polimer sealor and cover your boat.

Mel,
I'm confused because I am in the automotive paint business and I can assure you buffers are still used.

Sure there are shops still useing lacquer so let just say that if you are trying to remove oxidation from gelcoat try sanding with 1200 and 2000 grit wet dry paper and see the shine return.This method is fool proof in that the supper fine papers dont scratch, they infact pollish.

Where do you find those grits? Best I can find is 1000 grit at an auto store... I've got rubbing compound which I believe is 1500 grit.

I like that teflon boat polish to protect once I've got the oxidation off..

Jake, I'd still like to see a picture of a vertiglassed hull. My used prindle 19 hulls are just starting to show their age a bit and if this stuff works like you say, I'll be ordering some. Well just as soon as I actually get a storage space and off the waiting list and I can bring the boat down from my in-law's house

Hey Josh,
As I said earlier I bought the kit from the Marine Store and they have pictures in their testimonial section that I've given the link for below. Vertglas testimonial pictures

Greg

thanks greg, thats deffinately a good looking product, I'm all over it!

Jay,
Any automotive paint or fiberglass supply will have 2000 grit. However I assure you you do not want to sand your 20' boat with 2000. I've used 600 and then polished gelcoat with a buffer and trust me the 600 sanding scratches polish out. Leaving 2000 grit scratches on the hull will only lead to quicker dulling and discoloring. There's no doubt that a 2000 finish will have a shine and be smooth but its still not a polished or sealed surface.


Mel,
Lacquer paint is not legal anymore. It's been outlawed because of its VOC's. The only people that can get it are people that can prove that it's being used for restoration purposes. Were talking classic cars.

All cars are painted with urethane based paints. Most cars are two stage paint. The base coat is the color and dries to a semi gloss finish. The clearcoat is sprayed over that for durability and shine. A friend of mine has a body shop. I can assure you that every car he paints gets wet sanded and buffed. He uses 1000 grit then a aggressive compound then a foam pad with glazing compound.

I do touch-up paint repair for high end car dealers. I use 2000 to remove very fine scratches that are in the clearcoat. Then those are polished with a foam pad. If you want to test your theory that 2000 polishes try it on your car and let me know what happens.

I really don't see the need to use 2000 for any other reason.

So, you still want to wet sand with these grits?, then I would do it this way, Go to Wally Mart and buy a jitter bug air sander. Find a capable air source and put your thousands grit paper on that. That way you can run water and let the machine do the work.

It does what they say and those pictures are real. In the kit, they supply you with a "white" 3m scotch brite pad (the color indicates the abrasive grade of the pad) for removing the loose oxidation in combination with a rubbing compound. This still requires a bit of elbow grease. I recommend using a buffer (a real one) with the supplied rubbing compound and just quickly go over the gel coat for much faster and easier preparation. Then wash the boat, dry it, and start putting on the coating. DO NOT go over the vertglas with the buffer (it quickly turns black) and don't get acetone on the vertglas unless you intend to remove it.

Daniel,
A few points,


This product sounds good but I would be interested to see how it holds up to repeated washings, sliding over the decks on and off the wire etc. Has anyone used it on their cat yet?



I believe I suggested he try sanding and polishing first.



I don't understand this at all. We use sand paper to prep the hull before painting. It removes the oxidized stuff and gives us some tooth for the paint or Gelcoat to adhere to. Yes some paints are better. I painted my old boat in 1989 with Imron. Four years later I polished it and it hardly made the boat look any better. It has the same paint job on today and the guy that owns it hasn't done anything to it at all. I walked over to recently with a little wax a rubbed a spot and it shined right up.

What do you consider a short time?

Wyatt, What did you paint your boat with? Imron does not chip off as long as the most basic prep work is done.

Most large yachts I've seen are painted not gelcoated. Some of the Tornado's of the top teams have paint jobs on them. My Hobie had areas where the gelcoat was 3/16 thick. Paint can be a few mils thick. Lighter.

Looking at the cost factor 1989-2005 at $70 per year. You can buy a nice paint job for that. By the way it cost me a couple hundred bucks to get the paint done. The 303 may work but where does all that stuff wear off to? The water? I have a 20' boat it's going to take more than a bottle and more than ten minutes.



Now understand, my current boat is all Gelcoat and I don't have any plans to paint it. However finding Gel that matches is not easy. I had to have some custom mixed so I can do repairs that come close. With paint it's easy to do spot repairs that match perfectly.





Another way of looking at this is some of us use our boats. Your quite a ways up there. Your sailing season is how long?
I sail from March into December. My boat goes in on Friday and comes out on Sunday and thats almost every weekend.I actually use my boat to have fun and sometimes race. It's not uncommon for me to sail 150 miles in a weekend. That means going places and pulling up on beaches. It's unavoidable and silly not to enjoy this area when all it costs is a few hours twice a year touching up the bottom.

Bottom line is you make these decisions after carefully looking at your indivdual needs and weighing all the options and no matter what you decide to do, do it right.

Enjoy.

Catman,

Before I respond to your thoughts, I want to go back to the beginning of the thread. Greg wanted to know what caused the oxidation damage to his hulls. It's caused by a particular spectrum of sun light, ultraviolet. Sounds like he tried to repair the damage and he was dissapointed his effort to do so didn't last.

We're all so busy in life that every time we are confronted with a new experience, who has time to investigate everything and why reinvent the wheel. Somedody tells us how they tackled the issue and we follow their advice; after all we were the one without any relevant experience. But there's practical problem with giving advice. You can't say, just do what I tell you, cause they're a lot of us who might resent a sailor standing in for god. So I figure, to each their own, and am inclined to keep my mouth shut. But if you could sneak inside my skull you might hear, jeez I wonder why that guy insists on paddling upstream.

Hull damaged, above the waterline, doesn't appreciably alter a boats sailing efficfiency. So it seems to me when hull oxidation bothers us it must have to do with damaging the boat's visual appeal. For my part I like shiny stuff. Also, personally I hate spending hours of hard rubbing; it's just more work than I want to do. I'd rather putter around less strenuously than end up feeling like my hands and shoulders are about to fall off.

1500,2000 will remove most oxidation you must seal the surface after with polymer sealer or restorer. Good luck sorry we got off topic.If you turn off you computer and start working your boat you can go sailing this weekend.

Hey Mike,

Sorry I couldn't finish answering your points, something came up.

From the various comments, I gather some of the guys would rather sand and wax. I respect a guys' right to do things as he sees fit. But I would have to say I disagree on several points with some of the methods discussed here; not as a matter of choice, but rather because I think they're either incorrect or ineffective. I've been puttering around with boats for about fifty years now. And as Greg noted I'm an autodidact so I'm pretty interested in learning. Boy you asked a lot of questions. This is gonna take me longer than polishing my hulls. For what it's worth this is what I've learned about caring for plastics exposed to the sun. I hope the following will answer you questions.

1.) I've used 303 Protectant on many watercraft, for many years. Properly applied, it seeps into the hull depending upon the porosity of the gel coat. The surface film will wear off with use (water, wind, skin, anything that rubs against it) over time. That's why I reapply it every so often, throughout the season.
2.) Similarly, Vertglass too is absorbed into the gel coat, depenent upon porosity and it's remaining residue will also similarly wear off.
3.) My understanding of the two, from a chemist's perspective is, 303 possesses superior anti-oxidant blocking agents. Both are applied the way. 303 is also quite a bit cheaper.
4.)The effectiveness of both is contingent upon proper surface preparation.
5.) Depending on the number of coats, they both create a "slippery" effect on the hulls. The first couple of sailings after the original application of 303, when I trapped-out, my feet felt like they were resting on ball bearings. I had almost zero traction. So now I coat the hull side where my feet rest when trapped-out, with a thinner coating and rub it in well, removing all the excess. I've only used Vertglass on canoes, kayaks, and runabouts so I don't have personal experience with how exactly how slippery it is underfoot.
6.) For the purposes we are talking about, that is, "esthetics" and nothing else, I would never sand the gel coat of my hulls. I don't care what grit is used. Period. The sun is already actively destroying my gel coat, I don't want to assist it in that regard. If it's just about shiny hulls, don't buy sandpaper and DON'T SAND YOUR HULLS. I'll get to abrasives in a minute.
7.) PREVENTATIVE MAINTENANCE. (I can't use the quote tool, to reference your particular question, so bear with me.) Maybe some confusion on this thread is coming from not separating two distinct topics: ongoing hull maintenance and hull restoration work. For example, I've got a 2005 F17, so practically speaking I don't have hull oxidation (yet). To prevent oxidation I do preventative maintenance at the beginning of the season by applying 303 with a saturated rag and wipe down hulls, spar, boom, beams, stainless metal, blocks, rudders, dagger boards tiller bar & stick, and coated shroud lines and forestay. I also coat the hulls once every couple weeks or so when I'm done sailing for the day. I just wipe the hulls down (I don't crawl under the tramp) with a rag damp with 303, not dripping wet, and kind of just polish the 303 into the boat. Maybe takes me ten minutes. Prior to launching this spring I flipped the boat and gave the bottom of the hulls a real thorough rub down and have repeated that once this summer. I'll do it again this fall when I put it to bed, so it will be ready for next spring. The only reason I do the bottoms is to prevent (or maybe I should say, lessen) stains, dirt, and crud from attaching to the hull bottoms.
8.) RESTORATION. I also bought five older cats this spring. The hulls were in varying conditions of deterioration. So in this example I had a lot of work ahead of me. To loosen and remove the oxidant I used a fine grit rubbing compound. I don't use sand paper for this because a.)the slurry doesn't "plug up" like it does with sandpaper; b.)I can get very fine abrasive compounds in an emulsion that floats then over convex surfaces far better than fixed sandpaper; and c.)controling the amount of pressure needed, especially on undulating surfaces, can be done more effectively through the sensitivity of one's hands in a way that is far superior to the work produced by a scrub pad mounted on a buffing machine. Commercial operations almost always use buffers when applying abrasives and some of these guys are really proficient. But you and I, saiors undertake this once, twice, maybe three times in our lifetime. You think we get proficient? The only thing we get good at is cutting off half the remaining gel coat the sun didn't get to yet. From experience a softer touch will control the removal of the oxidant from the still solid gel coat. The goal is to removed the damage, not the remaining gel coat. Take an old thin rag, ten or twelve inches square, fold it over until your hand pretty well covers most of it, pour the coumpound on the rag until it can't hold any more, and start rubbing in circles. Keep adding coumpound to maintain a slury on your work. The rag helps hold more slurry than your hand, but it's your fingers that keep telling you to push harder or lighten up. Remember all you want to do is to remove the broken down crud. And you can't see it because it requires magnification. Figure you'll do it only once to your boat so spend a saturday morning and do it right and be done with it forever. I can't tell you verbally how much effort to apply and when to stop. I could only show you. the condition of your hulls dictate that. If you insist on a buffer, all I can say is go easy. They can really make the compound cut fast. Remember with a machine or by hand, the stuff is going to dry on your hulls as you move on to unworked areas and must not only be removed, but the liquid antioxidant must also be applied before you know whether you removed enough material or too much. In order to make an oxidized hull surface shine, it must be abraded. The surface worked with an abrasive compound and cut off all deris, the high points, and irregularities. But it's a double edged sword; we're make fresh scratches on the hulls order to remove existing ones. By using a very fine grit in a slurry, we make microscopically finer cuts as we work the surface, thereby removing the oxidized mat, large cuts and scratches. Upon finishing, thoroughly wash off with soapy water and rinse. Then the surface will be properly prepared for "finishing". Hull color is in the gel coat, if over aggressive sanding didn't remove it. At this point apply the product of your choice and seal the surface well by patiently rubbing it in. Additional coats of either continue to fill the microscopic depressions until the Nth coat leaves a uniform surface and produces a deep glossy appearance. Guys who like shiny now uncap a cool one and sit back and smile contentedly at their own reflection.
9.) Your own experience with your old boat is a great example illustrating what I've tried to say. Polishing an old paint job (fully oxidized by the sun) or nicely oxidized gel coat hulls doesn't work!!!!!!!! Unless your willing to do the correct restoration required in preparation for the finish coat, you'll get, as you said, unimpressive results. You polished a four year old paint job with wax and as you say, ..."and it hardly made the boat look any better". This was because you didn't remove the crud and get down to fresh gel coat. Coming back to the boat months or years later, you dabbed at a spot with some wax and it shined right up. But like Greg's original observation in this thread, wax doesn't last but a couple weeks at best. Why? Because UV breaks wax down faster than greased lightening. Wax isn't particularly easy to apply, and for sure it's time consuming, so why go through the effort for something that doesn't work.
10.) Mike, assuming we're talking about maintenance and not restoration, your twenty foot boat is only two feet seven inches longer than my F17. Ok, maybe it will take you fifteen minutes instead of ten for an occassional hull rubdown.
11.) Unless you have a serious crack that's leaks or threatens structural integrity, or a very deep scratch, you don't ever putz around with the gel coat. Otherwise there won't be any color matching left to do.
12.) No Mike, I disagree with another way to look at our boats is, as you say, by looking at the part of the country we reside in or how much we use our boats. The level of care a guy gives to his boat is his determination alone. So the choice of boat maintenance is yours. As is the amount of time you use the boat. You made an assumption that because I live far north of you I don't sail much. That's not relevant at all. If it was your point wouldn't fly because what you don't know is I've sailed a heck of a lot more than you this year. At least according to how often you said sailed on the weekends; which incidently sounds like a lot of fun to me. I know you weren't aware I took the summer off to sail as a means of doing a more enjoyable physical therapy for some injuries I sustained. My intention was not to say how you should use your boat. Rather I was trying to make a point about me and how I take care of my boat, relative to how I use it. If I lived where you live, I'd go with you, and pull up on the same beaches right along side of you. Hull bottoms are'nt damaged by UV. I'd still coat the bottom of my hulls really well, because it would give them some marginal protection they otherwise wouldn't have. That's all. I agree with your closing sentence: it's the operative idea for a prudent sailor.

I'll be done sailing up here sometime in November. If the hurricanes are gone by then, maybe I'll come down and explore your waters. Though I confess I'm a tad touchy about sailing with sharks. Hope I addressed your points.

Happy sailing
Daniel

Not True. I applied Vertglas to the non-skid on the deck of my monohull with no ill effects. The non-skid was not quite as grippy to bare feet as before but with proper deck shoes it was actually grippier. Vertglas is not an oil or anything like it. It's a hard coating that is more like paint than wax (but somewhere between the two) but it is thin enough to really get into the pores of the gel coat during application before it fully hardens.

Dan,
I'd love to respond but I'm going sailing!

It'll give me time to eat MY spinach and adjust my Halo.

LOL

Jake,

I know what Vertglas is. I've got several gallons of it in my shop. Seems to me Jake, you put yourself in a bit of a duplicitous position when you tell me my comment is not true and then go on to say when sailing barefoot it's not quite as grippy as prior to applying the Vertglas; but that can be remedied by wearing good deck shoes. I didn't realize at the time that less grippy was a more acceptable description than slippery. That Jake is a distinction without significance. You say you applied the stuff over nonskid material on a mono hull. Most mono hulls put non skid on horizontal surfaces. A little less grippy on a horizontal surface, may be compounded when applied to a vertical surface. It sounds like you're disagreeing with me, though you haven't run a meaningful test.

I'm ignorant of some aspects of both of these products. Such as performance factors that extend beyond my own personal experience with them. I'd rather not make any claims beyond what I know. I was attempting to describe all the issues I could think of, so that the serious guys who had never used either product, wouldn't be hit with unforeseen surprises.

As I said in my earlier post, I've never used Vertglas on a cat. So personally I don't know what effect it may have, if any, on trapping out. You seem to be supporting the observations I've made on other boats, regarding increased initial slipperiness. Meaning the possibility that Vertglas may have an effect on trapping out by potentially making the hulls "less grippy," at least to barefoot sailors, especially without benefit of nonskid underfoot. When the first guy who actually puts this stuff on the sides of his hulls and sails on a "Verted" cat and comes back to this thread and tells us what happened, then we'll have something to go on. Until then it's conjecture.

At least as of now anybody who wishes to use the stuff will be better prepared. Because heaven forbid, had somebody applied Vertglas to their hulls and set sail on a gusty day, they well may have found themselves suddenly flying around the forestay, and as we all know there is simply no excuse for that kind of sailing mishap. So together we've made the world a safer place.

You know Jake I may be wrong, but I thought Greg Hill started this thread because he was interested in improving the "looks" of his hulls. Don't you think your disagreement over an interpretation of the quantitative intent of the word slippery vs less grippy just obscures the more important issue of UV hull damage and the potential value restoration products may offer some sailors?

Daniel

Mike,

Get crankin, Rita's comming. I'm just back, been out all day, blowing around 12, nice and steady. Don't forget to double dip the spinach. Gotta be big and strong to wear a halo.

Daniel

This may be a tangent from the topic, but while all you experts are here.....does anybody know what product would be best to put on the rotomolded plastic boats like the Wave and the Getaway to make them shiny and to repel road tar and generally make them easier to wash. Oxidation does not seem to be a problem with the material used for these boats; and sanding is not an option.

Would products like Vertglas or 303 work on plastic, even though there aren't any pores to seal? Rick says wax might work, but the boat would be slower.

Anybody have any ideas? I want my Wave to be shiny! Or at least clean.

Easy there Popeye - I didn't mean to offend you. I always wear shoes when sailing, hence, my comment that Vertglas does not create a slippery surface.

All I know is..... today I Vertglassed my hulls using the 3 step process the kit recommended and OH MY GOSH.... What a difference. 10 minutes after putting everything away my neighbor came over to borrow a saw and when he saw the boat he said, " You buy another boat? That thing is gorgeous..."
THANKS JAKE for putting me onto this stuff. I don't care what Popeye says about you.....
I'll take some "after" photos tomorrow and post them.
I hope now it lasts like they said it does.... You think it would work on the mast too?
Greg

Mary,



Either of these two products should work for you. We started building fiberglass whitewater canoes and kayaks in the mid 1950s. The boats were stored outside and after the first season we noticed they all had faded from sun exposure. It got progressively worse when we moved to Colorado because we then spent the summers running rivers at high altitude so by seasons end all the boats had faded even more, and worse the bottoms received a brutal beating from paddling thru younger boulder fields. A general way to think of the various agents that give fiberglass or carbon fiber their stiffness is to consider them all plastics and to include rotomoulded products in that category also. Because there are many different methods used it's risky to say definitively that something will always work. So with that in mind, we never manufactured using roto moulding because of the added weight and expensive tooling. But we did apply both Verglas and 303 to the rotomoulded boats of those who enrolled in our seminars. If I was you I'd order a small amount and try it. Using either of these (or several others similar to them) will give you additional benfits that no one has yet mentioned. First, our seminar clients were mostly serious whitewater competitors and they wanted to produce more speed for the same amount of energy expended. If you prepare your hull bottoms thoroughly, as I've suggested earlier in this thread, and apply these types of products, your hulls will slice thru the water more efficiently than without it.

JAKE----Serious racers like yourself may want to consider doing what I said I did to my boat-flip it over and coat the bottoms. And coat your rudders and the exposed part of your dagger boards also. After several summers of testing we used 303 on hull bottoms for competitive events, because it gave us faster boats. That's not a knock on other products. It's a reality that sailors will have a harder time flipping their boat than a kayaker, so they might elect another option as more feasible. Jake I did not take offense. I'm particualr on being told something is for certain, when the example offered in support falls short. I listened to what you said and I would still make the same point; it seems reasonable that a nonskid horizontal surface may produce a different response than a vertical smooth surface. I've put Vertglas it on plenty of boats, but I never stood on a vertical surface with Vertglas on it, and therefore I can't make a definitive statement. I can say, boat decks have always, for lack of a better word, felt somewhat more slippery after being coated than prior to coating. For my part I don't know what the response will be, because I have not yet put Vertglas on my hulls and trapped out on them on a windy day. My reply to you was you haven't sailed on Verted hulls either. I did caution folks as to my experience with 303. You may have other info you haven't mentioned, but with what we've said, does my reasoning at least make sense to you?
MIKE----For saliors like youself who find themselves hauling their boats up on beaches without cat trax, another attribute of these products is, to some degree they help prevent scratching the hull bottoms. It is highly unlikely that the gel coat on any boat is uniform in thickness and the bottoms may have areas that are thinner than desired. Sliding over sand on a regular basis will wear the already thin gel coat thinner. For this purpose Vertglas was better for protecting our hulls. When ran heavy boulder gardens on expeditionary streams in South America we didn't care about speed and "painted" our hulls heavily with Vertglass type products.
GREG----Earlier I mentioned the various parts of the boat I cover with these type products. For me the most important unit on my boat is my carbon mast because it's the most expense. I gather from listening to this forum, most sailors probably won't consider dealing with drag as very important. Nonetheless reducing water drag is a big factor in going fast. However there is plenty of drag aloft also. Even a lonely forestay creates a know amount of drag. Larger objects create a lot more. If it was my boat, I'd coat the mast.
MARY----Another effect of this stuff is that it really does a good job of protecting your boat from dirt and grim. This is because it helps to seal the surface, denying particles a foothold, so to speak. So If I were you and I was going to haul my boat up north for the summer I'd coat the boat before I left. You may arrive at you're destination with road grim on your boat but it will hose off much more readily. Ric is correct regarding wax. I've already commented on the failures of wax. To summarize: wax is hydrophillic, when instead hydrophobic characteristics are far more desirable. This means wax attracts water, hangs onto; with the net effect that it increases drag on the boat. The products we are discussing repel water in varying degress, and in so doing they reduce drag. The other point to make is, wax breaks down very, very rapidly when exposed to two elements in particular, sun and water. Minnesota has long been involved in composite research and here they always seem to be tinkering with their formulas. I don't know how porous Hobie boats are, but as I said we've used several different formulas on roto moulded boats because it improved performance, by protecting the bottoms from excessive scratching. If it was my boat I'd certainly give it a try.

Longevity. Greg, I'm assuming because you were dissapointed with your ealrier attempt that you followed the directions for Vertglas to a T. If you've put your boat to bed for the winter and cover it with a tarp or store it inside you'll make it through to next fall just fine.

I do want to remind everyone that this stuff is a very good product for the reasons I given above, but it will not stay on indefinitely. That's dependent upon the amount of exposure to sunlight, water friction moving over the hulls, and how much the hulls are hauled over the ground. I've been sailing five or six days a week so I don't expect my hulls to stay covered indefinitely. That's why I mentioned that every couple weeks I give the hulls a quick ten minute rubdown.

I'm not suggesting other people follow my routine, or that I have a favorite product. I'm merely trying to enlarge your level of awarness so you can make better decisions based upon your own circumstances.

Hope this helps.
Daniel

Thanks, Daniel. Very helpful. Now I just have to find some of the stuff.

Mary,

I'm sorry, I thought I'd previously mentioned where to buy this stuff. 303 Protectant is sold all across the country in hardware stores and Home Depot type retail centers. Online you can buy it from any number of boating sites. For cat sailors, Murrays.com stocks it in several sizes; 8 oz./$7.95, 16 oz./$14.95, plus $7.95 shipping (pretty steep shipping). We buy ours locally, by the gallon. As I've mentioned this stuff is great for protecting neoprene wet suits and booties, life jackets of any material, hiking harnesses, boat covers, mast, boom, shroud lines, blocks, stainless steel, cat trax wheels, fiberglass cat boxes, and just about anything else that takes constant abuse from the sun. Suffice it to say, this is really good stuff and pretty cheap.

Vertglas does not have anywhere near as large a distribution network. I don't know where it can be purchased retail. I buy it through a chemical distributor who only sells to manufacturers willing to maintain large volume accounts. For individuals, I think buying it online at Marine Store dot com is probably the best bet. They carry a couple of sizes; 16 oz./$26.95 and 32 oz./49.95 plus $5.95 shipping. We only use Vertglas in limited applications. I prefer 303 on my F17 for several reasons and would just summarize by saying I like its' higher performance qualities.

Vertglas is less known than 303, which doesn't mean it's useless. Hundreds of manufacturers, worldwide recommend 303 to their customers. The manufacturer of Vertglas doesn't know much about how their product holds up under various conditions, let alone which surfaces will absorb them. They make understandably cautious claims. We do a lot of testing before we make a claim and as I've said I don't know how long either product will cling to the polyethlene surface your own boat is made from. I'd like to suggest you purchase 8 oz. of 303 and apply it to one hull and 16 oz. of Vertglas and apply it to the other. I realize I'd be spending your money but I'm really interested in the outcome. Also your boat is exposed to higher UV in Florida than more northerly parts of the country so it would make for a great comparison.

I've got a call into the engineer who developed 303 to see if I can find out the answer to your specific question. My hunch is it will work just fine.

I should probably make a clarifying statement so sailors will know where I stand regarding the relative merits of Vertglas vs 303. "303 protectant is head and shoulders above ANY product we've used since 1980." That doesn't mean Vertglas is worthless, it means 303 is better and a lot cheaper. But unless both of these products are applied correctly, neither will perform very well nor will they last very long. When I observe the condition of cats in various fleets, it becomes obvious that cat sailors in general, aren't very interested in maintaining their boats.

Correctly applied, Mary, your boat will sail faster and last for the rest of your life with no appreciable damage to it. If your interested in pursuing coating your boat with 303, I'd be happy to tell you how best to apply it.

Good luck
Daniel

Hey Mary,

303 Protectant available right here!

http://store.catsailor.com/tek9.asp?pg=products&specific=jrqqcocpe

Shhh. I don't want Rick to know about it. His hulls don't need to go any faster.

Okay, finally stopped raining so I could take a picture or two or three. Here is what it turned out like.....
I think it is miraculous. If this is what Vertglas can do I can't imagine what 303 will do seeing as Popeye seems to think 303 works better.
Thanks again Jake. I've very pleased.
Greg

Picture two

Picture three

Ohhh...so you're taking Popeye's word over mine?

That looks great!

Thanks. I think so too.
I'm saying I can't believe ANYTHING could work better than this..... (sorry Popeye)

Greg, That looks great! I have used 303, but think I'll try this stuff come Spring. I cleaned my hulls with Barkeepers Friend, and it seems to have really eaten the gloss off the gelcoat.

That's awesomely gorgeous! And it sure looks fast. But I guess we still don't know whether it is slippery for trapezing -- and for righting the boat?

I'm telling you - on the deck of a monohull healing at 20 degrees punching through chop without the aid of a trapeze line....it's livable gription barefoot and great with shoes. Most certainly that can be applied to trapezing.

To get technical about it - the static friction while barefoot remains the same...perhaps reduced a little initially. Static Friction while wearing deck shoes goes up dramatically. Kinetic friction while barefoot goes down dramatically (i.e. once you start slipping it's more slippery) while wearing shoes it is still increased a good bit.

Static friction can be losely interpreted as how grippy a surface is when neither of the contact surfaces are moving relative to each other - they are "static"... i.e. how much pressure it takes to get your foot to move while it's planted on the hull. Kinetic friction is resistance to motion between two surfaces when there is already motion between them (like resistance while you are already sliding). They are two very different values and the static friction is typically greater than kinetic friction. In this case, while barefoot, the static friction remains about the same while the kinetic friction becomes a good bit less.

WHAT???

September/October are the best months of year in New York. My weather station said 14 knts today and it was a bit higher yesterday. Just amazing days. Keep sailing, I know you buffalonians don’t get cold. No shirt? Bills game?

Matt

I'm still looking for the before pictures??? It would be nice to compare.

Mike Hill

This may be a silly question, but if these products make a boat faster in the water, does it also make them faster in the air? I mean, hypothetically, would you save a little in gas mileage when trailering? With the prices of fuel these days, every little bit helps -- and we always pull two boats double-stacked.

I would say that the jury is still out with regards to if any of these products actually make a boat faster in water (or air).

Before pictures, Mike....

Picture 2 before Vertglass

I'm talking hypothetically here, Jake. If it IS faster in water, would it also be faster in air?

I can't stop taking AFTER photos.....
Mike, I'm telling you the shine before the Vertglass was non-existant. It looked like flat white paint with no reflection at all on the outside of the hulls. The inside of the hulls showed some reflection but nothing like this.
Now it looks like the boat is wet all the time. In fact, my wife asked if she could touch it or is it still wet. That was two days after painting this stuff on.

Greg- did you do the whole kit or just the vertglass part? I just got the whole kit in the mail today and will probably start the process today.

I did the Oxidation Removal with the scrubby pad they provided. I went around twice washing the boat off periodically. Then I waited a day and washed the boat using Step 2 boat wash. Let that dry completely..
Finally I painted on Step 3 and I just continuously painted till I had 6 or 7 (I lost track, quite frankly, cause I was listening to the Red Sox game at the time)coats on. My hands were sick of painting and it was getting dark so that is all I've done and I still have enough stuff to put more coats on at the beginning of next season if I want.
Good Luck. Hope you get the same results I did.
Greg

Yes - but the affect would be ever so slight and tiny that it wouldn't be measureable. If you were trying to move the hull through air closer to the speed of sound - yes, it might make a measureable difference. However, at highway speed, the resistance due to airflow is more about profile drag than skin drag...and when changing the finish of a suface on the magnitude of these coatings, you would be affecting skin drag.

Skin drag is largely affected by how thin/thick the boundary layer of turbulent airflow is between the skin of the object and the smooth laminar air flow around the object. There is so much outside turbulance coming from other cars, the tow vehicle, and cross breezes that your not going to get a steady boundary layer no matter what you do. Hence the skin drag (through air) can't be significantly impacted by a coating on this level and at these speeds.

Disrespecting laminar flow?!? BLASPHEMY!!



I'll Paypal money for a six of Newcastle Brown Ale to anyone that can post a reference to a credible, objectively executed drag test that puts to rest the hydrophobic/hydrophilic debate. Preferably with a .edu, .nasa.gov or .navy.mil URL. I have yet to find one.

Just finished with the oxidation removal (FLIPPIN WATER STAINS!) and wash... looks better already... but as with washing anything- the flaws really stand out when you look at it THAT closely.

Did you take "before" pictures???? Hope so. Love to see them.

Greg

More after photos......

Last one....

I'll double that ante!

Jake,

Check out Bethwaite's book. I believe he mentioned something about waxing vs. not waxing his "GREAT ALMIGHTY AUSSIE SKIFF".

It's not documentable enough to win the brew, but it's a start.

I agree with the comments that polishing hulls does accomplish two things:
(1) it puts you in a racing mindset by focusing your brain on going fast
(2) it offers you the opportunity for CLOSE inspection of the hull, and you can spot and repair scratches, road grime, crud, etc. that could slow you down.

Last time I polished the hulls (about every 6 months), I noticed some scratches that I repaired. I wash the hulls before every race, and I once found that my daggarboard tape was sticking down (which has GOT to be slow), and fixed it.

This probably is only something the top sailors need worry about, since more of us blow races from bad tactics, bad technique, or just bad manners....

Either that or someone can Paypal me $100k and I could get some time in the Navy's tow tank at Carderock.

\
OK, but you owe me big time.
I was RC at the Savannah Olympics and we had a couple of lay days. I was staying in my RV behind a warehouse that had a couple of old wrecked cars.
So, I decided to do a speed test on surfaces.
The hood of this car was slightly downhill.
I set up several race tracks for drops of water to compare the time it took for each drop of water to move down it's race course.
Here are the race tracks
1)nothing
2)polish and/or wax
3)McLube
4)Rainex
5)McLube and Rainex

Results (as I vaguely remember them):
1)nothing = the drop did not move
2)polish and/or wax = the drop did not move
3)McLube = 9 seconds
4)Rainex = 11 seconds
5)McLube and Rainex = 1 second

Now if we could just keep McLube and Rainex on our hulls all the time, we would really be hot. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

When I got my diesel RV Stan Woodruff and I pushed it pretty hard and when we arrive at Sandy Hook for the Wave NAs, the boats were pretty dirty from the diesel soot.
Stanly worked hard for hours cleaning his hulls, but meanwhile I had talked to Mary. She explained that diesel soot is a long chain polymer.
I won the regatta. <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />
Rick
)

Greg,
Your original hulls looked pretty good compared to many I've seen. I recall you did a lot of work on them a little while back. Now that you've "Verted" your hulls they look great. Congratulations! If you applied the stuff correctly and continue to re-apply it according to the specs, you'll be a happy guy. By some of your comments, I noticed you misunderstand some of my comments. As do several others. You don't have to appologize to me. Listening to the feedback, I think we're talking past one another. I'm pleased somebody finally did something. Several times now I suggested some advantqages to using UV protectants, irrespective of brand. If it makes anyone feel better to use one instead of the other, by all means do so. Something is usually better than nothing. If you're the kind of person who's curious, or even skeptical, about the kind of marketing claims we are all continually bombarded with in this country, then you'd probably want to ask any number of probing questions to help yourself sort things out to your advantage, not Madison Ave. advantage.

I'm loath to open up Pandora's box (sorry Jake) and start discussing avionics. If I read this thread correctly it seems that it's more important to be right than correct. Jake is incorrect regarding whether these products, when properly applied, decreases drag. I don't think anything I can say will change that. I'm not even sure Rick's experiment will suffice. Jake and SteveH and those who doubt the drag reduction comment, would be better advised to go to a credible Physics Department on their local college campus and see if they can bend the ear of one of the post docs for an explanation.

Mary,
It sounds like you first must determine if this stuff makes things go faster in water, before you can move on and discover whether it does the same for an airfoil. I think you've indicated that your boat already goes fast enough, so I fail to see any advantage in doing a test. And you'd also have to move from the hypothetical to the material. I think the greater advantage for you may be in trailering. You would arrive at your destination with a cleaner pair of hulls or hulls that would wash the road grim off with less effort.

SteveH,
A six pack of beer, especially Newcastle, isn't much of a stimulus. Last time I was there the Britts don't even drink the stuff since they started pasturizing it; it's kinda like Bud for them. However, as I suggested a visit to your local campus may find a more willing taker. There is a caveat though, in addition to maintaining healthy skepticism when you walk through the doors of the physics lab, your required to have an open mind.

PTP,
Whether you need to use the entire kit depends upon the condition of your hulls.

In case any of you are still sailing out there, today was nasty. Steady between 20 and 25 and frequent gusts of 30 and better. As a newcomer I reserve the right of silence regarding whether we went over or not. Unfortunately no other cats were on the lake. There was a group of diehard boarders and some fall kite sailors out. Sailed an F18 all morning and a 6.0 this afternoon. We could take all but a couple of the boarders, I suppose because of the heavy waves. I'm sworn to secrecy so I can't disclose whether the hulls were coated and if so, what with. You know how it goes, ...orders from headquarters.

Daniel

OBJECTIVE DATA!!! Rick, you've at least earned a couple of bottles of substandard beer. However, not sure that it's 100% applicable. The surface tension of the droplet would play a part in the race and wouldn't on a hull. Also, in my googling of 'hydrophobic hydrophilic drag test,' I came across a reference stating that some coatings can be hydrophobic in air and hydrophilic in water. So if the RainX/McLube coating is hydrophobic/hydrophilic, which side wins? Yeah, I know, doesn't make sense to me, either.

Daniel, thanks for the suggestion, but almost half the people in my hallway at work are physics Ph.D's and I wouldn't trust them on SWAGging this nor on running the test. All I've seen for both sides until Rick's results is ad claims and intuitively obvious anecdotal evidence put forth by messageboard experts based on some other messageboard expert's intuitively obvious anecdotal evidence. I'm not claiming to be either right or correct, but if you can't bring anything objective to the table, then no beer for you. BTW, I'm fine with Pandora's boxes.

How about the one where Hydrophobic wax (regular 'ol wax) would make your boat float higher because it pushes water away?

I'm an enginerd and have never heard any testing that anyone performed that was objective and thorough in relation to waxy, oily, or wetsanded hull bottoms flowing through water. You can tell me until you are blue in the face that you think your boat is faster with this coating or that or that you were faster than sombody else without but it's not objective. As an example, it always seems like my truck runs better after a washing although I know it's physically impossible. Point is, personal opinion and "feel" are not adequate enough to stake a claim on some scientific result. Show me the money! Until then, I'll focus on keeping the bottom of my boat clean and fair and trying to avoid mistakes on the course.

Here's the kind of test that doesn't cut it. It's for the hydrophilic coating, Hyspeedkote. The results look interesting. Interesting enough to include in a test, but there are too many uncontrolled unknowns in real-world testing. This is what it takes for a thorough, objective test. A controlled environment, a carriage that can maintain a set speed and electronics to measure small differences in forces.

BTW, that's me on the plank. Seriously, $100k and a week at that tank and the answer is known.

Would a hydrophilic coating make the boat sit lower in the water?

All this stuff is bringing back my ice cream headache. Hydrophobic, Hydrophilic, it's all Hydro-PHALLIC to me....

All I wanted was purty, shiny hulls and I got em.

New question..... Triradial vs. Horizontal-cut dacron sails.
What is the difference? Why do I want one or the other. Why does Triradial cut cost a lot more? $820 vs $ 975 from Calvert for a 5.0 oz Yellow Square-Top Dacron Main.
Thanks
Greg

Wouldn't a thicker boundary layer produce less drag? Wouldn't a surface that is not as slippery to water produce that thicker boundary layer? Wouldn't this lead us to the non waxed/coated/slippery hulls being faster?

The box has been opened further.

Triradial is better because it aligns the fibers in the direction of stress on the sail. Thus the sail is consistently stretched throughout.

Triradial costs more because you waste more material when building the sail because of the many cuts.

Mike Hill
www.stlouiscats.com

The pre pictures are further back in this forum. I am not sure the pictures do it justice, but the system is pretty amazing with vertglass... it was amazing to see all the oxidation washed off the boat with the first step.. I have no idea how many coats I did with the vertglas- maybe 6 or so- some parts more than others. It DOES look like a new boat... now I guess I have to do the centerboards.. ugh

and another

last one... then maybe this thread should go bye bye.

Looks good. Glad you like it. It's really hard to take pictures that do it justice. In person it's much more impressive.

Have a great weekend.
Greg

Busy week,
But I do have some comments.
Greg your boat looks good. I have a friend that purchased a older faded yellow H14 and I plan on getting him to try it. Good tip Jake. I have seen this stuff at boat shows but I am skeptical of these kind of products and am tired of wasting my money on the latest quick fix that doesn't work. Fact is it's still just a band aid but the best I've seen so far.

I preface my comments with some of my experience just so you know. In the late 70's early 80's I worked for KIWI BOATS. We built custom one-off racing yachts. IMP,LOVE MACHINE, EVERGREEN, KIALOA IV. Just to name a very few. We were on the cutting edge building composite,balsa cored boats. Back then we built them on a male mold. As you might guess the outside of the boat is raw glass and has to be finished by hand. So how do you fair a 81 ft. hull to perfection? Sandpaper, fart rock, putty,epoxy primer, paint and a lot of work day and night. We also built the KIWI 40 and MINI TONNER in female molds. Those had gel coat exteriors. For the last 22 years I've worked in my own business touching up cars. The last 5 for high end dealers only. I have had Cats since 1982.
I don't claim to know everything but I do have a good working knowledge of finishes painted and gel coated.

One other thing Greg, none of us really explained why your hulls look good for a short time after you buffed and waxed and then go bad so fast. Picture a cross section of the surface. A new surface is smooth. A degraded surface looks like a mountian range with peaks, valleys and slopes. When you buff you polish only the peaks. Not the slopes which depending on how bad the surface is has much more surface area than the
peaks. You have done nothing to polish or remove the oxidation from the slopes and valleys. Wax leaves, right back where you started.

If the gel coat is not that badly degraded it can be sanded and polished. We have first hand experience not coming from me but MBOUNDS. He lays out a good schedule of sanding. The only thing I would add is a guide coat so you don't over sand or under sand. A guide coat is simply a can of flat black spray paint. Dust it very lightly on before you start sanding. Sand until the paint is gone. This will also show the highs and lows which may be too much info for some. Sanding should be done by hand with a board file and there is a right way to sand. I could go on and on about this and if anyone wants to know more PM with your PH# and I'll gladly call you and discuss it.

Fact is there is only few ways to fix bad gel coat. Polish,sand and polish,re-gel coat or paint.



Daniel,
This comment,are you speaking of yourself? Let me straighten you out on a some of things. My comment about polishing my painted hulls meant after four years they looked as good as the day they were painted. Like Greg's hulls do now. I don't use wax,I was simply trying show the guy who bought my boat how nice it could look. It's all I had at the time. I have argued against waxing for racing on this forum before. The paint has lasted longer than any gel coated surface I have seen.

You say don't sand and buff, but you say it's ok to use a rag and compound. Talk about paddling upstream. The gel coated surface of a cat is the best surface you could ever get to buff for an amateur. It's not that hard to learn.

I've given you examples of painted boats. No comment?

I did go buy some 303. 16 oz bottle. Now it may help keep a new boat looking new. The bottle says 100% Prevention of UV caused slow-fade with regular use. SPF 40 for your stuff. Like your comment about Vertglas I doubt it. I can tell you that on the places I tried it there was no difference in color or sheen. I used a third of the bottle just on my decks in front of the main beam. It does not make an old boat that needs restoration look better. I have friends whose boats have aluminum strips on the bottom of their boats to help protect the hulls from beaching. Trust me the aluminum wears. This stuff will not prevent any wear from the beach.

Referencing your comment above. A lot of people visit this site to get info. Some are people that have never had a boat before. Make sure you don't cause them to paddle upstream.

As much as I do like the vertglass- I agree.. nothing will protect the boat from being dragged on the sand- in fact.. when I was using the oxidation remover you could tell there was less oxidation under the boat from the "polishing" of draggin it across the sand occassionally (although, admittedly, the bottom of the hulls get less UV rad).

Steveh,
He may not have the credentials your looking for but Jack Sammons wrote on this subject in his book Welcome to A-Fleet. I think he's in the sailing hall of fame on this site. He discusses the various drag layers and does not recommend wax for racing. Though the book is written for the Hobie 16 it has a lot of good info and is well worth reading. It's also fun to read. Problem is I don't know if it's still in print. Someone has to have a copy.

Rick, did you use regular RainX or the concentrate that you add to the water in the washer fluid tank?

Jake, I'm thinking if you push the water away you go deeper.

Assume a glass-smooth finish. The problem as I see it is that, according to boundary layer theory, that very first layer of water next to the hull is going at hull speed no matter what the surface is. So unless that magic coating can allow that first layer of water slip by in violation of the theory, what's to improve on?

Steve,

The navy has been working on this for years. They discovered years ago that dolphins and whales as well as many fish exhibit far less drag than theory says they should given their shapes. They think they have it down to some substance exuded by their skin. Every now and then you hear a little blurb about it but I have not seen anything published recently. Not suprising with the Russians revealing their FULLY OPERATIONAL super-cavitating torpedoes. Can you say ketchup?

Jimbo

Maybe it's not as complicated as we think it is.

We have been through this before. Catamarans are in the laminar flow regime. That means the water touching the hulls does not move. For all practical purposes, as long as the surface roughness is the same, it does not matter what is on the surface.

Because wax makes the surface smoother a hard wax surface, should make you a little faster. Hydracoat, hydracote, etc. are supposed to work by adding something to the water to reduce boundary layer friction. The only data I have ever seen says you need a lot (about 1 beer bottle per day) A few drops wiped on before a race is not going to do anything, for very long.

I do not know how this, "do not wax" idea got started. "Welcome To A Fleet" has helped it and some other odd ideas keep going. I do know that knowledgeable people have told annoying novices silly things like "don't wax your hull and 2000 grit wet sand it with the grooves all going in the same direction" or "wipe the rudders with raw fish oil" and armor all the tramp to help you get across faster".

If you really want your boat to go faster, wash it really good at the regatta site.

I will not argue this point anymore, go look it up for yourselves.




As for vertglass and such, I used it on a monohull I was trying to sell. I think it is thinned water based polyurethane. Think of it as a delicate decorative finish. It is sensitive to UV and do not ever use harsh cleaners. It will look like old varnish. Opps or ammonia will take it off if it starts to look bad. I have never used it on catamarans.

It is slippery but that can be fixed. I use my leftovers to make non-skid. I add Interlux grit to it and roll it where I want it.

Carl

" I likes to rub me and me boat down with day old Squid before I race"! Ow, me head hurts ...3m wax makes her slide right up on the beach and straight thru umbrella and beach chairs just ask mr. Chip from Delray. The day he slapped a tourist sunglasses off with rudder was pretty impressive too,as his 6.0 was skidding sideways sailing up the beach, the bottoms of these boats are all in great shape still.

I've been using Starbright marine polish with teflon for quite a few years. I don't know if it's a wax or not.



This stuff is to protect a good finish not for restoration. I put two coats on about twice a year and it seems to keep my new boats looking new. It also makes the hulls slicker so that they wash easier. I would not go near my hulls with sandpaper until they were in bad shape with lots of oxidation. I would also not ever paint a cat. The paint looks great until it starts getting dinged up then the old color shows through and the boat starts looking bad.

Mike Hill
www.stlouiscats.com

I disagree that cats are in the laminar flow regime. They may be traveling at a speed where one would expect laminar flow under ideal conditions, but there is nothing laminar about the the flow near the air-water interface. Too much entrained air and eddies from the wave action. And those eddies will be deep enough to affect a portion of the dagger and rudder, so I'd skip prepping for laminar flow on those, too. Another problem with laminar flow is that it separates more easily than turbulent flow and separation is the big drag producer.

Once you accept that laminar flow is, at best, a fantasy and, at worst, undesirable, then you can move on to the smooth vs "rough" argument. Personally, from the journal articles that I've read, I see turbulence as sort of a microscopic version of separation. With separation, there is an adverse pressure gradient that builds up near the surface due to viscosity, and when this pressure reaches a certain value, the flow separates from the surface forming a coherent eddy structure behind the object. The way to prevent this from happening is to induce randomized, turbulent flow which brings energy down closer to the surface. Well, a similar thing occurs in the boundary layer of fluid. A coherent vortex structure builds up with vortices forming and bursting in periodic fashion and the thinking is that a randomized "rough" surface prevents this coherent vortex structure from forming.

But, there's arguments both ways, some more supported by experimentation and theory than others.

Not that I'm worried about a bit of this on my cat.

So which produces the "lesser of two evils", the rough or the smooth?

Rough. Though rough is on the order of hundredths of a millimeter. Plus, there's the possibility that the same disturbances that prevent laminar flow could prevent the coherent vortex structure from forming so the point could well be moot. Extrapolating results from one situation to the next doesn't always work.

Good to know, although I'm going to keep my hulls shiny until someone can prove to me that the shiny hulls are slowing me down more than a blown tack or getting rolled at a starting line...

Smooth vs. Rough or Textured? Remember the 12 meter Stars & Stripes down in Australia. Riblets. They won that one. Fun topic.

RIBLETS-You do not know what a riblet is? It is not an animal. Airlines in the United States are saving $300,000 a year because of riblets. Here is the story behind them:

Scientists at NASA tried to figure out how certain water creatures could swim so rapidly. They studied porpoises and sharks for months. The friction of the porpoise's body as it moves through the water ought to be great enough to slow it quite a bit. Yet the amount of drag that should be present-simply was not there! Given the drag of the water and the amount of flipper motion, something was enabling the porpoise to swim much faster through the water than it ought to be able to swim.

Then the experts figured it out: riblets. These are small triangular-shaped groves on the outer surface of the porpoise's skin. They are also found on fast-swimming sharks, but never on the slow ones. These grooves run from front to back. As the water touches the body, it is carried along in those riblets, and this reduces the amount of frictional drag as the large creature swims rapidly through the water.

NASA's Langley Research Center developed the riblets and tested them in wind tunnels. They then asked 3M Company to manufacture riblets in large, flat vinyl sheets. When these sheets were placed on the outside of large airplanes, the resulting savings were immense. It now costs airline companies a lot less in fuel to fly a jet liner a given distance.


Just when you think you got it all figured out.

Kind of like the dimples in a golf ball. Should we all be orange peeling our gelcoats? Maybe next time you mess up a paint job you can tell them "Those aren't fisheyes, those are speed riblets."

-Rob V.
Nacra 5.2
Panama City

More on riblets.

http://oea.larc.nasa.gov/PAIS/Riblets.html

http://www.google.com/search?hl=en&ie=ISO-8859-1&q=3m+riblets&btnG=Google+Search

So it looks like boats sanded with 100 grit with the flow would be the fastest.

I always knew my 18 was fastest with the 100 grit finish.

Everyone can be happy all the time...
Due to flow types The ideal is a polished hull for the forward third, sanded for the rest, and a waxed stern to repel water..

Mike,

One of the articles indicated that this advantage was lost if the angle of attack (direction of water vs. direction of riblets) increased over 15%. I would guess that the bobbing up and down of the boat would cause large deviations of the AOA, which would reduce the efficiency.

Also noted was the increase in total wetted surface caused by the riblets, which if memory serves, increases drag... Do the benefits outweigh the drawbacks? You be the judge.

Interesting discussion nonetheless....

There was a paper in Nature, v388, 21 Aug 97, pp 753-755 with a summary on pp 713-714 that described a test using random protuberances. The random did better than the regularly placed roughness, presumably because the regularly placed roughness produced a coherent vortex structure, albeit smaller than the smooth surface structure. Has the added benefit of not needing to be aligned with the flow, though the test setup in the the Nature paper was flow in a channel, not past an object.

The proper way to test something like this would be to use the smooth surface area of your object as the reference area. That way, any effect of the larger gross surface area are factored into the difference in drag coefficient. However, a vendor presenting the data might disagree with what is proper.

gelcoat shmelcoat, buy a boat with a high quality paint job. Super slick yet not too slick to screw up attachment, no wax or slime needed to restore surface, just detergent.... low maint. Easier to touch up and repair scratches and dings.

Jay,
Yeah I read that and the depth of them need to tuned the expected speed. However they seemed to work down under where the boats were sailing in big seas.

For what it's worth I like a scratch free smooth surface polished with a non-silicone polish. The water sheets off the hulls, doesn't bead.

Eric are you saying the ARC's are painted? Who's twisted idea was that?

I was at Robbie D's this eve and asked him what was on his Tornado....It wasn't gel coat.

Then...What do those guys know anyway.

I think it's more about surface tension, adhesion and low/high surface enrgy interfaces. A displacement hull has to push aside an amount of water equivalent to that it displaces at the speed of motion. The water 'wets' the surface to some degree and adheres viscously impeding the hull's motion. The water moves out of the way as fast as the hull goes, up to a point, at which the hull begins to plane. At that point the water is no longer 'wetting' the hull surface. So planing happens when the hull moves swiftly enough to exceed the capacity of water to move out of the way. Note that this is a pretty good analogy to subsonic and supersonic flight.

But there are other ways to reduce surface wetting, certain surface coatings for instance. Low surface energy coatings cause water droplets to bead up rather than spread out into a thin film, implying poor wetting and thus adhesion.

Jimbo

To further stir up the issue, the most applicable test data I know of, is rudder testing by some British grad students (Looks to me like they had too much free time). If I remember correctly, wax made no difference. The lowest drag and best flow attachment was with a 3200 grit finish. A real 3200 grit finish would be like a brand new camera lens.

So get to work. Try a high speed buffer, white plastic rouge, and continous water mist. Oh and be sure to clean the bugs off your hull after you trailer to the water. And the sand or grass off when you get it in the water. And Oh, maybe the scum, slime, and bits of stuff while its in the water.

Or you could just wax it to make it pretty and wash it before you race.

(For those of you whose native language is not English or have a hard time with humor, the last half of this was humor. In the real world, a 3200 grit finish on a catamaran might last until the dust settled on it. I would be hard pressed to maintain an average 600 grit finish at a regatta)

Carl

Carl, do you have a reference for that rudder testing?

Part of the study was on madforsailing.com or the Daily Sail with a link to the university library for the complete article. I read when it was a free website and did not think to copy it. Maybe someone with a subscription to The Daily Sail could find it for you.

I was told that someone found the article by going into the Online University Library search system. I can't confirm that.

There are actually lots of articles available on this subject however most are hard to for the majority of people to read. For example.

The Relationship Between Frictional Resistance
and Roughness for Surfaces Smoothed by Sanding
Researcher: Assistant Professor Michael P. Schultz
An experimental investigation has been carried out in the 380-foot towing tank at the U.S. Naval Academy Hydromechanics
Lab to document and relate the frictional resistance and roughness texture of painted surfaces smoothed by sanding.
Hydrodynamic tests were carried out in a towing tank using a flat plate test fixture towed at a Reynolds number (ReL) range of
2.8´106 – 5.5´106 based on the plate length and freestream velocity. Results indicate an increase in frictional resistance coefficient
(CF) of up to 7.3% for an unsanded, as-sprayed paint surface compared to a sanded, polished surface. Significant increases
in CF were also noted on surfaces sanded with sandpaper as fine as 600-grit as compared to the polished surface. The results
show that, for the present surfaces, the centerline average height (Ra) is sufficient to explain a large majority of the variance in the
roughness function ( &#8710;U) in this Reynolds number range. The results of this study have been published in the Journal of
Fluids Engineering


If you have access to an online search and retrival like a University Library. You will find many articles on the subject.