TMS-20 update 6/17

TMS-20 Update
Closing the access port.
When I was in the earlier stages prior to joining the hull halves I wanted to glass in the first bulkhead from both sides on each hull half. The reason was because this bulkhead although small carries load from the bow sprit and forestay and once the hulls are joined it is not accessible. The bottom half of the hull was easy it was open before the hulls were joined. So I planned out an access port once they were joined to get the rest of the bulkhead glassed.

I made two backing plates. One patch panel was 90 degrees to go against the bulkhead and hull to give a bite for the flat patch panel it was glued in place before the hulls were joined. The second flat patch panel overlapped the cutout. The flat patch panel was left loose inside the hull when it was glassed together and I tied a string to it so I could pull it in place when it was time. I also built a ridge in the bow area so when the hulls were joined I glassed them together by the ridge.

The first two pics show the access port and making the patch panels. The third pic is the carbon bonding the bulkhead to the hull working though the access port. Also when I joined the hulls I edge glued the bulkhead to the hull side with a bead of thickened epoxy.

More.....

Just for fun let's pretend this is a repair job on a carbon / foam boat. You would cut away the bad. Form some type of flange, and then create a backing skin. This is the point that I'm at now.

The flange could be strips glued that overlapped the cutout and the inner part of the hull. The flange would build a lip that a formed piece of pre-made skin could be fastened.

Happy Father’s day to all of you dad’s out there. The boys are home this week-end but the family let me work on the boat some. Here are a few pics of what I got done before the rain started. We really need the rain so……

I finished the frames to hold the boat upside down so I’m working on the keel to fare it out to get ready to tape the seam. Then some more faring and get ready for the bottom outside skin. I’m also working on closing the access hole on the port side around the chine. I scuffed up the area, fitted a piece of carbon, wetted it out with a bog of west systems epoxy with 404 thickener, lay-up up the carbon, then put the cut-out back in and clamped in place.

If this was a repair job there would be more of lay-up but in this case the cut-out had a lay-up on the back of the foam already. Then you would place the foam over the inside skin.

More pics

Epoxy dried and dished out some for faring

The first layer of bog.

Not pretty yet but I want good saturation and make sure it filled all the cracks and voids.

The next step would be the outside skin after the repair is fared out. In my case that will be a week or two as I go back to working on faring the keel and taping out the seam where hulls join. I will tape it out with one 4" strip of 200 gram carbon and then a layer of the lightest Kevlar cloth I can find locally to cover the keel area that will be exposed directly to the beach. Next a layer of E-glass (white) fiber glass cloth so I can sand and fare as Kevlar does not sand well it balls up and frays. The Kevlar is for preventing punctures from any sharp objects or rocks when beaching. Once that is completed I will do the normal lay-up of two layer of carbon and one layer of E-glass for the outer skin.

Fared out as far as I'm going to take it at this time until I make the final faing for the chine and top lay-up. Working on the keel at this time, pics later in a week or so for next update.

Also working on getting a new job more travel in the US but more time off to work on the boat.

Hi Mike:

This is a little off subject for you, but have you ever thinned gelcoat? If so, with what and how much?

Thanks.

looking good. what size rounds are you going to shoot out that bow sprit? ;p

MN3-Funny my son and I talked about that it would make a great potato cannon.
Pete yes I've used acetone. Enough to get 10 drops from the mixing stick. Not too scientific. If the gel coat is really old and thick buy new it is fairly cheap. I'd say about the same thinning I've done with Lacquer paint if that helps. Once thinned you may have to do multiple coats with a little flash time in between.

Thanks Mike.

Pete what are you putting gelcoat on?

MEK, Styrene, or Acetone. I prefer MEK as it flashes off a little more slowly than Acetone. Styrene is the best to use but it's nasty nasty stuff. Duratec makes a good product that you mix 50/50 with gelcoat to act as a thinning agent and to allow it to air cure. It works well, although, I've found that it makes white gelcoat too opaque for my liking.

DO NOT THIN TOO MUCH with the solvents. If you do, the gelcoat will not cure properly. I would thin just enough to spray...make sure your spray gun has at least a 2.3mm tip if using a spray gun. Quality of the gun is not very important...you're going to have to finish it later anyway.

Thanks guys. I'm refinishing my boat but I'm going to roll it on. I just don't like spraying.

Never thought of MEK that works also. I always seem to have Acetone around the shop and it works.
I agree Styrene is pretty nasty so I’ve been staying away from it. Actually I've stayed away from all Styrene, polly, and ester based products the last few years I started to have reactions to it. I guess I played with it enough over the years that my system was getting pissed at me. I’ve been happy working with Epoxy and it does not stink! The only complaint I have about epoxy is that it takes at least overnight to cure up enough to work on it. With all the work I’m doing my neighbors do not have to put up with a styrene smell coming from my shop. I walked into a large fiberglass supply house in Ft Lauderdale a few days ago and the Styrene smell was getting me high.

Pete you can add some wax to it and it will help it seal to dry and sand better, just cant re-roll it with out sanding.

Thanks again. Typically I roll two coats, wet sand roll two more coats, wet sand and buff. It doesn't take quite as long as it sounds but it is time consuming.

It is summer time so I may roll only 1 coat before sanding.

Pete: I'm in the process of putting gelcoat on the 20, and I do one coat, sand, another, and am about to put a final third coat on.

Sounds like we are going to have a few nice looking boats out there this summer!

I don't find it all that tedious and I don't have to deal with overspray. Most of my sanding is wet sanding so I don't even have dust to deal with.

I find sanding with a cigar and drink close by an excellent form of relaxation. Now if I can just get rid of this cough.

You're my kind of guy: I'm reading the forum right now smoking a Cohiba Robustos and sipping on a 15yo Talisker

can you apply Gelcoat with the HVLP sprayer given the correct tip and thinning?

I've only used an old cup sprayer Binks 7 - all metal.
I would suppose that a HVLP would work - that is a good question. With thinning, tip, and pressure adjustment it should work because the Gel coat is reduce to about same as paint for spraying.
Perhaps Jake or somebody else can help that has used a HVLP gun.

I keep on thinking about getting a new gun but I just rebuild my Binks each time. I have a “mini” HVLP for tight spaces and touch up but I not used it for anything but paint. A long time ago when I first started messing with cars a friend of mine who did show corvettes tutored me in shooting lacquer paint and a show car finish. But we all know that paint is only 20% of the job – prep is 80%. He helped me in the technique but always seemed to do better paint job it took me awhile to figure out why – it was all in the gun.
I was using a cheap gun at the time. For Gel Coat you can get away with a cheap gun. I have shot gel coat that came out pretty smooth with the Binks and it did not need to be sanded.

The last few boats I’ve used paint – auto paint on one for a custom job and Alwgrip on the other.

Gel Coat is cheaper the durability falls in between Auto paint and Alwgrip but the effort for Gel Coat is much more then both.

Pepin Cohiba Robustos - mmmmm from Havana?

you can use an HVLP gun for gelcoat. I do frequently. Just be sure your tip size is 2.3mm or larger. Northern Tool has a decent $30 gun with the larger tip (the green gun). There's no point in spending a ton of money on the gun...it's going to end up a little lumpy anyway.

I just bought a cup gun that has a 6mm tip (good lawd). I haven't had a chance to use it yet but am hoping to make a cradle mold with it in the next couple of weeks. The cup gun spits out unthinned gelcoat but is, in my opinion, probably not good for finish work (perhaps if you have a finer tip). It is great, however, for interior mold gelcoat prior to lamination and looks to be super easy to clean up.

I guess it's just up to the guy doin' the work. Imo, paint is for cars, gelcoat is for boats.

In the end I don't suppose it really matters.

A shine is a shine be it a 5 cent or 10 cent job.

How it gets there is up to you - unless you got a good friend or payin' somebody!

As a general rule gelcoat is best for boats.

And, also as a general rule, I am bad for boats (or at least Trap lines, right pete?)

Pete,

How big of an area are you doing.

I got one of the little Preval sprayers. It will do about a square foot at a time. You can thin the gel coat in the glass spray bottle, then clean the sprayer and then spray with PVA.

The whole boat. There are five years worth of nicks, scrapes and dings. Time for a face lift.

Gelcoat is best for HEAVY boats

Paint is best for LIGHT boats

Thinning of Gel coat, Someone said they used Lacquer thinner for gel coat. I never had, but I tried it. I have used mek solvent,styrene, Duratec, and Duratec thinner. I think the lacquer thinner worked the best. I have had no clogging of the sand paper when using lacquer thinner. Duratec is good but it adds a lot to the cost and I haven't seen the abilty of the gel coat to resist stain or loss of gloss improved by using it. Their thinner works great but is expensive. I haven't tried the the clearcoat they make but I will at some point.

Some of the dings will need filling. I was thinking of making my own bog by thickening gelcoat with cab o sil. The rationale: easy sanding, relatively water proof, the color will be easier to cover.

Thoughts?

cabosil (fumed silica) does not sand easily! use microballoons (preferably phenolic but glass microballoons will work).

Or...easier...use premium bondo (black/gold can with blue hardener...I think the can says "professional" or "premium"). I use bondo with good results under gelcoat. It has a polyester resin base.

Thanks Jake. I'll try the ballons.

I want to get away from any contrasting substrate colors. Additionally, I use such small amounts another can of anything will just clutter up my work bench while it's going bad.

That's one of the best reasons for gelcoat. It's easy to fix. there's also stuff called Q-cells that sands very easy.

Thanks.

the different colors can actually work to your advantage in they help you see how the fairing is going. I would suggest a light color rather than a vivid one so it won't show through on the final product.

Maybe a light grey under a white topcoat?

It's very hard to hide darker colors under a white top coat. At a distance they will show up as shadows.

It's simpler to tint the substrate the same shade as the top coat. Fairing is accomplished by dusting a light coat of black lacquer on the substrate and working until it is gone. It's like looking at a topographical map.

I don't rely on different colored material. I close my eyes while rubbing my hands over the faired spot while muttering "na na na na na na na".

be the boat.... beeee the boat....

Funny but on small spots I use the eyes closed method first. Some people have a good touch, I happen to blessed with a good touch. Sometimes I'll shoot just a dusting of light gray lacquer primer because it gets sanded off. Then I use lacquer thinner to remove the left over paint on the low spots once they are identified.

I used bondo in the past but not any more since I've switched to epoxy. Bondo will still absorb water and gel coat is porous no matter what anybody says. But for cats that live most of their life on a trailer it is negligible. I use West System with the light filler I think it is 410 that is cream colored.

That's why I like to wet sand, it enhances touch, imo.

I'm back to bondo, there just isn't a good source of material here.

As for gelcoat being waterproof, if it is how come leaners have such a terrible time with blisters?

They sit in the water all of the time.

I use the 410 for most final fairing, but I often get pinholes from tiny bubbles. I now use Dolping Glaze, an automotive glaze specifically for such minor imperfections. It goes on real smooth, and sands effortlessly. It's a 2 part polyester, not epoxy, but I've not had any problems with it. And I'm getting great life and gloss out of high quality auto paints. Flight Risk's paint is now 7 years old, and it's still glossy everywhere I haven't scraped it off.

Dave

Dave,

Great picture, but is there a reason that boom gooseneck is so low on the mast, and the foot of the main so high? Seems that you could either squeeze in a little more sail area, or raise the boom up a bit.. But I'm sure there's a good reason it's set up that way....

Shortly after I bought the boat the wingmast mysteriously broke 6' above the deck. Malcom, the builder, suggested moving the gooseneck to the main beam(like ORMA 60s) to eliminate boom induced forces on the mast. It's worked just fine, and it's easy to get across the tramp, either fore or aft, and mast rotation is induced otherwise. After the modification, the general consensus came to be that the mast was probably damaged in transit at some point. So I could move it back up to the mast, but I'm generally lazy. So sloth is the real reason the boom is rigged that way.

Dave

I like that term "Leaners" HA!

Has anyone used xynole-polyester fabric?