Dagger Board/Hull Repair (Minor)

Ok guys, I posted a while back when I first got my NACRA and the help was awesome. Now that it's getting warmer around here this weekend I figure I should do some work on her.

The dagger boards are a little banged up.



-The whole leading edge is scraped up as well. Can I fill in the chips and recoat the entire boards? What would I coat them with? I'm clueless.

Bottom of Hulls



Looks like they coated the bottom with something, no idea what it is. It is rubbed through in one spot into the gel coat and there are smaller chips here and there. I'm guessing this is because they lived on the beach to protect it a little but I won't be doing any beaching and if I do it will just be to pull it up on the sand at little islands in the Bay.

Any advice on smoothing this out? Maybe sanding down that coating they put on it?(The bottom looks thin, you can see light through when the sun is bright but it all feels solid, no soft spots, is that normal?) And what should I patch the chips with?

Any help is much appreciated.

Sweat equity into an abused beachcat. Been there. Done that!

You will become very proficient with gel coat finishing, Grasshopper, which can be very rewarding once you get the right equipment and practice. The brown/tan stuff looks like epoxy that is a repair from beaching and colliding with another object(s). If the tan epoxy is sound, fair it out with something like West Systems epoxy and build up the worn spots. If you are really compulsive, grind/sand off the tan epoxy to see what really lies beneath. Thereafter, shoot some gel coat. Goes on heavy (20mils?) per coat and requires prep sanding (150 grit?)to achieve a mechanical bond. I prefer to use non-waxed until my final coat to keep it tacky during build up via chemical bond between coats (I prefer 3 for you project and about 20 mins between coats).

Let it cure well (1-3 days depending upon humidity and temp). If need be, sand off any drips after curing with 220ish. Quick wet sand with 600 and then the magic. Rough cut polish (its like tooth paste consistency) with an electric grinder and buff wheel. Followed by regular marine polish with grinder and then hand paste wax and electric buffer.

I'll defer on boards.

does that daggerboard have a wood core? It appears to have been cut off on the end. To my knowledge, wood cores were not used in Nacra factory boards.

Sorry to Hi-jack but I am looking at doing the same thing on a Prindle 18 where the bottoms are worn thin. It's just worn through the gel coat I think and starting on the fiberglass. do I do the same thing with epoxy or do I need to layer on some fiberglass. I have never done this and have no clue but I am a do it yourself kind a guy and would really like to learn.

It there any step by step pages or books anyone knows about? What kind of sprayer can you spray on gel coat with? I have a spray gun that came with a compressor that I have never used. I would like to refinish/coat the entire hull as the current gel coat is pretty dull and faded.

I also may want to custom paint some with an airbrush but am not sure what paint to use for that and was wondering you can then put a clear gel coat finish over that?

Thanks! I think the tan(epoxy) is pretty sound. I just want to smooth it all out a little. That stuff is going to be in the water most of the time so I'm not super concerned about the appearance. Do I have to worry about the epoxy finish or can I sand it all smooth after it hardens? (I guess I'll find this out when I look at the instruction for the stuff but first hand info is always better)

So I should use another epoxy to build up the chips and thin spots?

The boards are structurally sound. They just look rough. Would spraying on some gel coat hold up to usage for a while?

Hi Guy,

Jake, I believe has some instructional videos of how to do Hull repairs that are very good .... Jake where can this gentleman see/view your videos???

Also Jeremy at Surf City Catamarans has some excellent videos also.

In the Hobie HotLine they have been running a series on doing hull repairs to Hobies .... your repairs are no different in reality.

In the pics it looks like someone used "MarineTex" to repair your hulls previously (availible at West Marine .... and DON'T you even think about using it!!!)

I use WEST Epoxy because of the ease of useage w/ the metering pumps available ... and there are thickeners availible to make it "THICK" ....

Find a local Automotive Paint Supplier in your area for wet/dry sand paper ... if you wish to spray gellcoat, and you use a seperate shop aircompresser make sure you use a Micron Air Filter to capture/remove compresser oil at the sprayer.

The better the repair and prep work ... the better the finished repair .... extra time spent sanding in the early stages .... saves time and materials in the end and leads to a better end result

I fill-in/repair my daggerboards every couple years and recoat them w/ WEST Epoxy ... I then sand them up to 2000grit Wet/Dry and then polish ... There is no such thing as a tooooo smooooooth daggerboard or rudderblade.

MD you have my E-Mail address ... or send me a PM, I'll tell you some of the tricks: brushes, mixing, gloves, tape for masking ... But view Jakes and Jeremy's video's ... excellent and you can learn so much just watching thats impossible to be explained adquately w/ words

Oh find DEFENDER Industries and Jamestown Distributers(?) ... you'll be purchasing you cloth and other supplies from them most likely.

HarryMurphey

I wonder .....

.... there are two easy ways to get a daggerboard to look like that ...

... Cut it with a saw ... or drag it on blacktop road at "speed".

Anyone want to place bets ....

Harry

You should try to avoid gel-coating over Epoxy. It's do-able ,but has a less than perfect success rate.

Don't even think about just slapping on epoxy and sanding it down later. That stuff is really tough to sand. It is hard and also clogs up sandpaper real fast.
Aim to get it right the first time around!
Dennis

I don't have any videos (and I've neglected my website for a while), but there is some detail on my website about doing fiberglass work and bottom jobs. If you really want to go overboard with it, my first part of an unfinished two-part series is here:

http://www.teamseacats.com/index.php?s=bottom+job http://www.teamseacats.com/index.php?s=bottom+job

Epoxy itself does not sand well and it makes a good filler only if you don't plan for it to be the last layer. Epoxy yellows quickly with exposure to sunlight leaving it looking pretty bad. Ideally, you want to fill minor imperfections with a body filler. There are marine specific versions but I've had good success with the premium bondo brand...make sure you use the premium. Body filler is not very durable and will definitely need to be top coated with gelcoat...but it's a really involved process to do all this and get a good result...and there's not much instruction on it. If you think you want to go this route, read that article and ask some questions - it might finally motivate me to complete part II!

"...but it's a really involved process to do all this and get a good result"

Yes and no. What are you trying to achieve?

If it's perfection then Jake is right 100%!

If you just want a sound boat for recreational sailing, and you are going to be dragging the boat on the beach, you don't need to be nearly so fussy. You can even apply gel coat with a roller. . . or not at all!

I had an old H16 that was more beer drinking platform than racer. When the bottoms needed to be done, I only sanded the repair with 80 grit and left them unfinished. The boat sailed just fine, and after a couple of "hard" landings you couldn't tell what the bottom was finished with.

well put pete...I went for the sort of anal-retentive finish that was better than new. For most people and most recreation, it's just not necessary.

Do you have any shots of the blocks that serious racers put their boats on? That might help this guy decide which direction he wants to go.

I'm actually doing the bottom job on my boat right now and Jake's tutorial has proven very useful. Getting the longboard is the key. It'll save you hours of time and without it, you risk your hulls getting all fubar'd.

Plus, strapping your loose hull to the sawhorse isn't a bad idea either.

yep. So when the whole thing blows away, you'd have metal sawhorses with sharp legs punching holes in all kinds of things. Better to just take the hulls off and put them on the ground.

Wow, those are some pretty hulls. I don't hope to achieve anything near that realm of repair. I basically just don't want it to sink on me and be fairly smooth so she glides through the water a little better. Once I take it apart and flip the hulls over I think I'll get a better idea of what needs to be done.

How hard is it to get a good finish when spraying on gel coat? Do you recommend being an experienced painter? Maybe down the road I'll restore the boat and get that nice gloss back to the entire hulls(maybe a different color? red, dark blue, would that work?)

Evercoat, polyester glazing putty. Sandable, primer freindly, marine product.... look iy up and see if it fits yer application. I think it does.

i had similar wear on the bottom of my nacra hulls

fortunately nothing had been done to them so i was able to clean them up nicely with 2 thick gel coat mixes brushed on with a paint brush, not perfectly fair but i don't race

if you've got a previous epoxy bottom job already on your hulls then you are probably best to continue with epoxy

something in epoxy inhibits the catalytic reaction in gelcoat, polyester resin, so it just stays tacky and either never sets or sets so weak that it peels off in next to no time

for your daggerboards, just clean them up with sandpaper and then give the bases a couple of coats of white gelcoat

for the leading edge chips/holes you could just fill them with 5minute araldite, or drip some white gelcoat in there a few times

What Eric is refering to is the "Amine Blush" that occurs in the final stages of the epoxy curing (at least w/ WEST Epoxy). Also note that research has shown that epoxies bond better to "cured" polyester resins then fresh/new polyester resins do. But there are a few tricks ...

1) Surface prep is KEY ...
2) You can not rush ... curing times are critical.
3) Gelcoat is designed to cure WITH OUT AIR ... so unless you are using it in a mold you need to have the formule w/ parafin(wax) so it will harden
4) If spraying gelcoat w/ an "aircompressor", compressor oil droplets can cause the gellcoat to never harden. You must use air filters to eliminate the aerosolized (small droplets) oil. Or you can just brush the gelcoat w/parafin on and sand the heck out of it w/ wet/dry paper ... start w/180 grit to cut the wax off then 220, 320, 400, 600, 800, 1000, 1200, 1500, 2000, ... now polish w/ polishing compound and it will look like Jake's!!!

Now, you can accelerate the epoxy's curing w/ heat and UV light. The trick to "amine blush" to let it run it's course which take 3-4 days in a garage/inside .... if outside w/ strong sunlight/UV radiation that time can be reduced. Sand the cured epoxy up to 600 to make sure the repair is Ok ... then resand the repair w/ 220 wet/dry to rough up the epoxy repair so that the gelcoat will adhere to the epoxy.

It's been my observation that most people "rush" the curing times .... with predictable results.

First you need to determine how much is missing from the bottom of your daggerboard, as there are several option on how to do that repair ... 1/2" or 1" or 6" it will make a difference on the technic used.

Harry Murphey

There are two more solutions, and in my opinion more reliable options, for curing gelcoat on an exterior surface.

1) Duratec gelcoat additive thins the gelcoat slightly so it will spray a little better and it also acts to promote curing of the gelcoat in open air - you don't need any additional additives to spray and cure. Reportedly the duratec cures the gelcoat harder than it would on it's own.

2) top coat with PVA (poly-vinyl alcohol). After you spray the gelcoat, you can spray a layer of PVA ontop of it to seal it from the air and allow it to cure. The PVA forms a "saran-wrap" esque coating that will peel or wash off easily once everything is cured. It is very water soluable and I use it all the time when I'm molding things to prevent resin from sticking to my molds.

Good Ideas Jake !!!

... those products just were not availible when I did most of my boat repair work. I started to become "Hyper-Sensitive" to the solvents and haven't done any major work for a number of years. I was stupid about taking baths in solvents ... dust masks .... etc

I've heard of such products , I just don't have personal experience w/ them ... but I've heard positive whisperings ..... I do have some small repairs to do (bows)....

The problem that took me the longest to reconize/understand/solve was the compressor oil contamination .... it was random.

Harry Murphey

I use a filter at my spray gun that screws inline before the quick disconnect fitting. I've not had any trouble with oil or water....knock on something.

Everything Jake says and... Spraying gel is pretty easy, and gel is very forgiving if you mess up. Definitely use Duratec, and you may need to thin it a bit more to make it flow. Use laquer thinner to thin it instead of styrene. I find that 3%+or- LT makes gel flow much better. Styrene yellows after a few years of UV exposure. You just have to take it a little slower with the coats.

Also, it doesn't take an expensive rig to get a good gel coat finish. Go up to your local Kragen, ect. and pick up one of their cheap gravity guns (no suction feed) on sale for $13.99. I swear you can't tell the difference between my $400 pro auto gun and the cheapo. I'll tell you the difference if I ever have a pot go off in my good gun.



Surface prep down to 320 is fine. (for most repairs I'll spray over 180 no problem and have sprayed over 80 for a quick and dirty) Once you're done, take it down to 1000 G and buff with this:


It works magic.

Hope that helps. I'm working od a video right now, but it's going to take some time.

J

The other way to get rid of epoxy blush is to use peel ply on your epoxy repairs (at the time of the repair.) Once you peel off the ply, you peel off the top layer of epoxy and the blush. And it leaves a nice level and rough surface for your next layer.

Wow I love all this new info. Is there any tips specific to asymmetrical hulls like my Prindle 18. All my wear covers a fairly narrow section on the point of the keels.

Bondo type products sand fast but they are not the best repair. It will collect water and swell and if water gets to the core of your board it is not good. The best repair is to use West System with a bonding filler to make a paste. The key to the repair is to have the surface clean and sanded to make a good contact. Be neet with your work. Read any body repair manual and apply the West System "paste" like bondo. Let it dry for a day or two the sand it out with sandpaper using a sanding block. You can use 120 - 180 - 220 - 400 progressive in grit.

Once you have it faired in you can buy gel coat and roll it on if you are not handy with air painting equipment. Make sure you add wax to the gel coat so it will dry tack free. From there you can wet sand the dry gel coat 400 – 600 – 800 – xxx.

The other option is to paint it with awlgrip paint it can also be rolled and it flows pretty well. Awlgrip is nasty paint if you do not know what you are doing gel coat is cheap and not as poisonous.

I’ll be repairing a dagger board on a Supercat 20 and document it. I need to get the picture part of my website up then you can see the steps. I've also done other repair work on boats and fabricated parts.

www.themanshed.net

A friend of mine, more familiar with fiberglass work, came over to check out my hulls today. He said they seem strong and it looks like the previous owner did just epoxy over the gel to beef the bottom up for beaching. So, I may just fill in the chips and sand that smooth. Would that be fine for every day use? I know it won't look pretty but as long as it can all stand up to the water I am fine with it for now. (since it sounds like gel coat won't go on over the epoxy very well?)

I'll definitely look more into the products you guys recommend such as the PVA. I just have to wait until it gets warmer here since I don't have a garage to do all of this in.

As for the dagger boards, I think the picture is misleading. It looks like the bottom of the board is worn but there is really about a 1/4" of some kind of clear resin on the bottom.

yeah, that's simply the very square cut on those type of nacra daggers

i was thinking of something with a nicer curve but realised that as there is no gasket in the lower slot they need to be that shape to fill the hole fully and so have the lease drag when fully up

MD,
I suggest filling in the bottom of the hulls with West and filler to make a paste it is hard. Bondo is a waste of time if you want to keep the boat. If prep is done gelcoat will work. You can use PVA but gelcoat wax additive to the last coat is cheaper and works just as well. Ask your supplier or look at Glue Products or same type of website. Gelcoat can also be brushed and rolled on the bottom it is out of site and can be sanded smooth. The key is to seal the glass.

Painting is great the best. If you have the equipment and knowledge or want to learn the ropes paint. It is hard but rewarding. I just finished painted this boat last weekend. The project included bottom work, fabrication, and fairing work. http://www.themanshed.net/supercat-20.html look at last picture. I need to get the picture part of website working I have a lot of repair type of pics that may help. I hope my webmaster gets that going soon, I just finished his boat....

If a slacker did the work, original epoxy, some people use epoxy when they should add glass. If your friend knows glass and says it is ok - you should be ok. I've seen slacker work, and I've had some of my old glass work popped when I suffered internal damage in the hull and the boat flexed after a nasty capsize. It is not nice to start sinking at sea, been there. Also I do not do any repair work with poly resin anymore.

If you "sail up" when you beach the boat and to just want to get by easy and cheap - tape off the bottom and go to Walmart and buy a spray can. The bottom will not show and it will sand off with each beaching.

Living and sailing on the beach for 30 plus years I've done my share of bottom jobs on cats. It is still thrilling to sail right up on the beach, baby the boat – I’d rather leave it on the trailer.

All of the posts are great, everybody is right it is up to you to decide. Me I'm a bit anal.

I've built boats, worked for several boat builders, built show cars, enjoy doing this type of "hobby", and I have 30 plus year of tinkering. It all started with a NACA 5.2 when they first came out and waxing then the hot cat a hobbie 16 in the mid 1970's. All of a sudden my 5.2 had a hole in it the 3rd race. Next weekend I learned repair work and it is all history after that.

My suggetion is set a few goals. How much money, time, and what level of effort you want to spend on the project. From those decisions you can go from Awl Grip, Gelcoat, Spray, Brush, Paint can from Walmart. I spent over 6 months of my free time on the SuperCat.

Enjoy!