Restoring a Gat 5.7

Time to put this boat back into shape at 33yrs old it needs some TLC.
Work to be done –
Strip off automotive type paint from hulls down to gel coat
Repair spider cracks
Repair some major cracks where beams mount
Reinforce soft spots in decks - inside hull and outside
Make new rigging
Add captured ball mast step and shroud extenders – supercat style
May add self-tacking jib
Re Gel Coat boat

I'm working with cyberspeed Craig to get my website updated so I can document the restoration with pictures.

I have been wanting an ORMA 20. A scaled down version of the 60' box rule tris.

Your project sure would fit the bill.

Now all I need I some good lottery numbers.

Have you ever seen 3Hulls project over on Multihull Anarchy. He started on a Hughes designed 20 footer. But as with you, life has gotten in the way. Maybe you could start a support group.

You are a true believer in there ain't nothing better than messin' about with boats.

Stripping
Ok just painting type stuff....I've been a stripper for a long time well I guess about 43 years. Boot camp taught me to strip wax off of floors and my boots. I've used spit, compound, sweat, rocks, abrasive materials, sand blasted, and chemicals. In the SeaBee’s we had to sandblast the inside of a water tower the Marines painted with lead base paint during the summer on Isla de Vieques in Puerto Rico the place where sailing captured my soul. I ended up in the brig for a few hours on that dang base…but payback you know the saying. I’ve also done more show cars then I can count. Ok back on track I’m drifting. Anyway you get my drift been there and I have a few Tee shirts.

So here is my take on stripping Paint off of a fiberglass boat. First rule never paint a boat. Second Rule: Gel coat (poly) on poly never on epoxy or paint. So you have to know what you are starting with to decide on your topcoat finish. A general rule paint does not flex like gel coat. White gel coat is about $45 a gallon the prep is about the same as automotive paint and takes some finish work after it is applied depending on your prep and spraying job. Gel coat can be repaired easily, is flexible and forgiving it can be spot patched if you mess up a spot or catch debris like dust or a bug when spraying. Gel coat can be rolled or brushed but the results are not as nice as when you spray. The surface must be faired out so when you sand out the gel coat after it is sprayed with fine grit sandpaper to shine it up you do not sand through it on the high spots.

I’m not saying don't use paint if that is what you want or need to use because of epoxy base layup. I’ve had very good luck with Awlgrip paint the prep is important as with all systems; the paint is very toxic and expensive. The automotive paint I used was high quality and lasted 5 years. Patching paint is difficult and repainting is often as much prep if not more than gel coat. As with all surface coats the prep work is the most import part and that is we are beginning. In my case ALL PAINT must be removed. All spider cracks must be fixed and repairs as needed completed and cured.

Let the stripping begin. My surface is a clear coat / base coat paint, faring primer, etching primer, old gel coat, and factory gelcoat. The stripper will eat some plastics, skin, gel coat if applied long enough, filler, and safe to assume anything you don’t want it to. I use to wear layers of protective clothing when I started using this stuff but now I don’t. I’ve had globs hit my kakis soak in and burn me before I knew what hit me. By the time you realize what’s up you have a burn. So I wear shorts and T-****s plus with the Florida heat less is better. I have a hose ready to spray off if I feel a hit of gel. The stuff is water soluble. Decide what is best for you. I use to pour small amounts (about a cup) into glass jars. I found plastic handled pour cups at Harbor Freight for a little over a dollar that hold up to the chemicals and even have a built in bush handle. I buy a box of disposable brushes they can be used also for all sorts of stuff including stripping and glass work, a box of 36 is less than $10. I usually use a new bush each application seems to work better. If you want to reuse a brush rinse it out and let it dry. The scissors in the photo are the best I’ve found and cost around a $1-$2 at Harbor Freight. I can cut carbon fiber all day and they are still sharp. I always get a hand full of them when I’m there.

The stripping gel is applied with short one way brush strokes do not brush back and forth. Its best if not in direct sunlight read the directions on the can… let it sit 10 – 20 minutes don’t let it dry on the surface. I use a metal paint scraper with a plastic handle - with a file I put a bit of sharp edge on the blade. Watch your angle so you do not gouge the surface. Scrape what is soft and curled take what it gives you. I found that about 3 coats of paint bubble up. I wash it down with plain water then apply another coat after the water has dried. After that the gel coat starts to get soft and gouges so I sand the rest with 100 grit paper on a DA sander. Adding more stripper does not seem to yield that much and cost about $45 a gallon so in my estimate you reached the point of diminishing returns at some point and could start lifting off the gel coat. Once you start using it you can tell how it works best for your application. Always hose it down with water after you scrape to stop the chemical reaction. Then hose yourself down because the paint particles will have a small amount of gel on them. Work in a well ventilated area and use fans and/or respirators.

The TMS-20 is sitting and waiting.

Some pictures

More...

after sanding

Just for the record, I've had a lot of success with polyester gelcoat over epoxy repairs. I think this perception comes from open mold production where you don't want to mix the (wet) two types of plastics.

If there are any substantial chemically reactive properties left from the epoxy resin post cure, something didn't mix or cure properly. Once cured, it's just a solid plastic just like a polyester based product and you are getting nothing but a mechanical bond with anything you put on top of either one (paint, gelcoat, etc.).

Ok, back to your regularly scheduled program...

Jake in some case you are right it depends on the cure time and the reaction to the amine molecules but I'm trying to keep it simple and fool proof no room for an adverse chemical reaction especially if some fresh repair work is done. You and I have been up the tree and in the pond with this stuff and know how to recover and what look out for plus a few tricks up our sleeve.

That is correct Jake, but epoxy has more adhesive power then polyester.
That has to do with the difference in the polymerisation process (the curing) which apply for the epoxy and the polyester resin.

The polyesterharder is only the katalysator and accelarator in the curing, while the epoxy harder plays really a role in the curing and hence in the bonding with the underlying surface!

Besides that the thermal expanding coefficient of both resins are not exactly the same, nor are the mechanical stressvalues. Moreover polyester shrinks while curing.

This leads to the following rules of thumb: epoxy on polyester is better then the reverse and also better then polyester on polyester.


Ofcourse you can have had succesfull experiences with other combinations; but think wise.

OK. But I'm no rookie when it comes to FRP repairs! You guys aren't giving me enough credit...feel free to browse a few projects many of which are epoxy on polyester and vice-e-versa.

So I don't hijack the Manshed's thread anymore than I already have, I've put the photos in this thread:
http://www.catsailor.com/forums/ubbthreads.php?ubb=showflat&Number=279637#Post279637

Dear Jake, I was just underlining the common rule for repairs where polyester and epoxy are involved.

I feel obliged to do that in order to make the repairs done by rookies, who don't know anything of resins, as safe and sound as possible.

There are wordwide a lot of guys who read these threads.


By the way, I love your pics which you showed us and I'm impressed by all your repairs.

Jake are you using West System Epoxy?

Yes.

No problem going over West System with Gelcoat. Just make sure the surface is completely sanded.

This repair done with West System.

it'll buff out

One other thing is make sure it's cured well. I would wait at least a week before coating.

Now THAT is a serious repair.