Acetone does sound like a long shot. Does it look like someone could've dropped a mast or rested something hard on your hulls?

Dirk,

Here's what most likely happened. The old gelcoat was most likely bad which means porous. So it was painted. You decide to re-gelcoat. Ok, but the paint's chemicals have made thier way into the pourous gelcoat contaminating it. Meaning even though it appears the all the paint is sanded off some must have remained. Gelcoat will always react when applied over any paint. Wiping the boat with acetone before spraying was not a good idea in my opinion. I would never use any chemical to wipe after sanding. Soap and water and a tack rag is it. Just a lot of chemicals there. I might of missed it when reading some of the earlier posts but when I said re-gelcoating was fine I didn't know that the boat had been painted. Knowing that I would of just repainted if I were you.

Also understand these chemicals take time to cure. Its not surprising that it took a couple of weeks to show up. I only hope the chemicals have used up their energy so this does not happen again.

Catman, While I agree that there are problems covering paint with gelcoat that should show up as a peeling gelcoat problem not what is happening on his hulls.

My only guess is that a heat lamp was used to set off the repaired area. The area got very hot and the foam under the skin shrunk from the heat. The outer layer wasn't affected. But now a void was under the outer layer. After the boat was in the sun for a while the unsupported outer layer of glass fell to conform to the shrunk foam. Thus causing the ripples.

That's my best guess. It doesn't help the situation but I hope that the boatyard will take responsibility and fix the issue.

Mike Hill
www.stlouiscats.com

yeah, I really doubt a gelcoat reaction caused that. However, any great heat damage should have been pretty evident shortly after the heat was removed (as was in my case).

I'm going to disagree with you simply because I've seen the result of gelcoat sprayed over a painted fiberglass surface.

A guy I knew had a perfect 69 Camaro with a fiberglass hood. A buddy of his had one he was fixing up. Well he who had was willing to help the buddy who didn't have make a glass hood for his car. Now these guys worked in the fiberglass shop at a boatbuilding place I also worked at. It was suggested to him that he would have to strip the entire hood before he could use his hood for the plug for the mold. Well he didn't agree. He felt as long as he put enough coats of mold release wax on, the paint would be protected. <img src="http://www.catsailor.com/forums/images/graemlins/smirk.gif" alt="" /> Well he was wrong. In fact not only did it ruin the paint but extensive damage was done to gel surface and in some areas it seemed to burn down into the glass. so needless to say they both were without hoods.

Lesson learned.

Also I can't find where Dirk said heat was applied to the area that had problems. Just guessing?

In the 27 years I've been around boatbuilding and automotive finishes I've seen some really strange things happen. When you apply gelcoat over something that has been painted with the possibilty of a laminate repair anything can happen. I don't see the boatyard as culprits in bad work. They could not have known what they were getting into until they did. I would have been more suprised to hear that there was no reaction knowing what the facts are at this point.

every mold i have ever made has beed taken off of a plug that has been painted with two part lp stuff with no problem.

Well this was back in the early 80's. For all I know the hood was painted with lacquer. I watched it done and saw the results. I don't believe anyone knows what kind of paint was on the boat previously. Cause for pause I think.

ya, you know what, we had a plug with some textured 'wall paper' on it. the paper was painted with lp, but the edges were sealed with lacquer and they [censored] themselves

gelcoat is a pretty good solvent for paint- styrene monomer is an unsaturated molecule- the next cousin to ethylbenzene- also a great solvent.

Catman Mike,or anyone else,

You have got me thinking.... (smell the smoke?)

I am using 3M Acryl-Blue glazing Putty to fill fine scrathes and dings on my rudders and boards. Do you have any experience with this product? Do you know if it will react to the gel coat or styrene?

I have no experience with that 3M product. I have no reason to think there would be a problem though.

I've just worked with that Formula 27 by Evercoat. Stuff works great and you can gelcoat over it and get it to match pretty easy.

Mike Hill

...she looks like a boat again!

even more important: floats!

this pic was still with the old 10 m sail on the 12 m mast, but luckily in quite some breeze, so did not miss my new sails too much that day.

with so many changes to the boat, it's quite difficult to say what brings what, but regarding the hull extension I am very happy. She cuts much nicer through the waves now and splashes significant less than before. Probably the new bows also generate more lift but with the new sails and the increase mastlenght and sailarea she will be quite some beast. Hope to post better images soon. Although the new sails finally arrived, summer is here and we enjoy what all Qingdao Olympic sailor will fear... less than 6 knots of wind all day long :-(

Nice going dirk. The boat looks great. It was a long time in coming, so go out and enjoy the light winds. In the fall you should be able to get in more full-tilt sailing.

Dirk,

Is the boom original equipment?

no, not many details are still original.
boom is pretty different from stock.the traveller track on the boom is not a standard but works pretty fine under load.

hi,

some sad news from the SC 6.5 ...
she dismasted last Sunday in 15-18 knots of wind due to a fitting failure...

searching for a new mast it seems I might be able to extrude one for a much more reasonable price than shipping anything here...

as an alternative to just extruding the same profile section like the original mast, I am also thinking of a redesign. anyone out here with some experience and knowledge to share?

thanks!

If its carbon - repair it!

Unfortunately, it is not. It is an aluminum section which already consisted of three parts and was sleeved twice. I used a carbon look sticker to cover all holes and rivets. That helped the look and the watertightness but well, guess it doesn't matter anymore...

I wonder why the mast sections we know always feature the same wall thickness around the profile? Wouldn't it make sense to have more material on the sides and less material front and aft? I guess the Taipan 4.9 section has kind of stringer reinfocements at the inner sidewalls for similar reasons...

Indeed,

Other masts have thickened sides for the same reason.

Wouter