Boat Repair/repainting- Vespoli pair

[ccrc1992]

I am in the midst of prepping my vespoli pair for a repaint. I have been sanding out chips and gouges on the deck and elsewhere on the boat, using a 3M marine grade filler where needed. I am running into problems, bubbles or little cracks are occurring in spots where I had previously thought I was finished with. The decks are the only problems, the hull has been a breeze to prep for it has primer underneath the paint. The decks are gel coat according to Vespoli. Do I need to remove all the gel coat on the decks or what should I do???? Please Help!!

-Adam

[completeIgnorance]

most likely there is water in your boat. Put it out in the sun during the day and store it inside at night if you can. I had the same problem with a few i just repainted.

[ccrc1992]

The boat has been out of the water for weeks now, it is as dry as it will ever be.

[petermech]

If the hull is heating up any trapped air in the honeycomb will build up pressure pushing the paint out of the way of pinholes and small cracks.

[Withoutmercy]

It sounds to me the paint is out gassing, either due to incomplete curing(too cold of temp, improper mix), or application over uncured product, a professional finish will not happen if this happens.
What kind of paint did you use?
A curing 2 part system or a one part put the color on type of spay can paint(such as a touch up can)? If it is a one part, it may be due to the lack of a hardening agent, or you have painted over uncured paint. Single stage uncured paint will not allow repainting after a set amount of time, (@20 minutes to less than an hour). The crazing and pin holes will persist until all of the uncured product is removed. Lacquer thinner will remove this paint and continue removal until all is removed. When all the paint is removed paint with a 2 part hardening primer and then a 2 part top coat. Remember proper mix ratios and temperatures when applying these finishes.

[ccrc1992]

I haven't repainted the boat yet, the paint is the original Vespoli paint. I am just doing prep work on it right now. I am having it professionally painted when I am finished, with All Grip. I'm thinking the sanding/curing of the filler is creating bubbles underneath the gel coat. Should I remove the gel coat or just keep working at it until no more cracks/bubbles form?

[theGraduate]

3M™ Acryl-Green Spot Putty

This stuff works wonders. Not sure how it reacts with your current materials.
It has solved all kinds of problems for me on finishing, from chipping, bubbling, and orange peal. It is light weight too.

Sands super fast and smooth.

[Norm]

Some random thoughts based on experience with shells and restoring an Austin Healey.

The hull is tougher than the deck. It's not going to flake or bubble because it is primer over a layer of carbon cloth. Unlike the hull, on the deck, you're doing prep work over paint (gel coat). Check with Klinger or the guy in Oak Ridge, but Gel Coat may have to be sanded off to get it perfect, and that's a chore. It will also save weight. Paint over paint adds weight.

I would also not use marine grade filler. It's super tough and likely harder than the gel coat or primer. Auto body filler is softer, and if you look at older beat up Vespoi's and other painted boats, that's what they used. The spot filler is also called glazing compound and is softer than auto body filler. It is not a 2-part epoxy per se. It sands off easily and is used to get the last of the repair perfect with very fine sandpaper. It's colored so you can distinguish it from the filler.

A tip. Be sure your fill spots are really clean. Dust will cause the filler from bonding to the surface and it can pop out later. Acetone can clean it and evaporate away. Acetone can also clean your brain cells away.

What color are you going to paint it? After all this work, it's got to be hot orange or red metal flake. List photos when it's done.

[Rush Scapegoat]

Having refinished a number of Vespoli 4s and 8s in the past few years, I've had the same exact problem you're having a number of times. The paint doesn't seem to bond to the decks nearly as well as it does to the rest of the boat, presumably because the tops of the decks are a light layer of fiberglass over the honeycomb core rather than a thicker layer of carbon fiber over the honeycomb core. I've found bubbles and cracks in the decking's paint both before I do any repair work, and then after repairing parts of the deck, likely because the sanding I have done to the nearby areas have loosened the already fragile bond between the thick paint and the decking.

On the first boat I repainted with this problem (it's only happened on the Vespolis from what I've noticed), I repaired and sanded out the decks as best I could, finished prepping the hull, and then painted it. Bad idea. Bubbles appeared on the deck not long after painting, while the rest of the hull looked great. In all subsequent hull repaintings with paint peeling/bubbling/cracking on the decks, I've removed the painting from the decking entirely before painting and it's worked out great.

That's my two cents, hope it helps!

[Scott @ Noble Hardware]

I did have one thought on what might be causing your problem. Gel-coat can be pretty porous. If you wipe the boat with any solvent, like acetone, and then do your repair work or lay down a primer coat, the the solvent might leach back through your new layers. And removing the gel-coat would eliminate the problem, which is what others have seen.

FWIW.