Automatically assume gelcoat?

[adams77331]

I have a 1974 fiberglass tri-hull. I am in the process of removing what I thought was a chalky, crazed gelcoat. I sanded a test spot today with 120 grit mesh and the finish is very thin. Also, sanding revealed a overall yellow coat on the fiberglass. Is this yellow primer or fairing compound? Second, is this boat really gel-coated? How problematic will it be to sand with 120 grit mesh with a power sander? How do I attach pics?<br /><br />Clay

 

[petrolhead]

Re: Automatically assume gelcoat?

To attach pics click on "Full Reply Form" below, to insert the pic click on "Image" at bottom right and type in the URL of your photo, that's it.<br />The photo must be hosted on the web somewhere for this to work, not on your hard drive.

 

[Elk Chaser]

Re: Automatically assume gelcoat?

The yellow may be the gel coat under a coat of paint. Someone may have painted over the gel.<br /><br />Keep in mind that not every coat of gel is real thick, I've found that some colors on my jet boat were thin and the main color or base color was thick. What was interesting was that the main color was the graphic stripes color.<br /><br />Nearly all fiberglass boats are originally built with a gel coat. It's part of the mold process.

 

[self taut]

Re: Automatically assume gelcoat?

the thin coat you speak ofe sounds like the mold release.it is a clear gel coat much like a clear coat on a car witch works as a release agent.tends to get a yellow color ang starts to flake afer a number of years.i suggest you go to a lighter wet/dry paper.as fine a grade as possible and wet sand.too rough a grade will take off additional gel which you dont want to happen.and the wet sanding will help to bring the shine back.the " clear coat" wont be too difficult to take off but will still take a good amount of time work and patients.careful around corners.

 

[cc lancer]

Re: Automatically assume gelcoat?

I respectfully disagree, to the best of my remembrance in 1974 the molds were heavily waxed with Carnuba wax.<br />There no way this wax could hold up for 30 years.<br />I agree with Elk Chaser, sounds like a paint over to me.<br />You can remove some deck hardware and see if there is any yellow under it. On the bottom are there any scratches, exposing yellow.<br />Any possibility this is a Johnson or Chris Craft?

 

[self taut]

Re: Automatically assume gelcoat?

not familiar with how it was done in 74'.my experience comes from a boat made in 78'. whole lotta changes in that time.mine was a thin layer of clear mold release which was very flaky and had turned yellow.mostly on the deck. the lower hull was actually still in rather good condition.

 

[Terry H]

Re: Automatically assume gelcoat?

self taut...mold release is what it sounds like...a release agent for the mold and gets cleaned off the finished product. Prolly what they used is a clear gelcoat, and it will react as did the finish you are describing...just a thought

 

[self taut]

Re: Automatically assume gelcoat?

I stand corrected

 

[ThomWV]

Re: Automatically assume gelcoat?

There's not mold release agent left on that boat. The yellow stuff is the actual glass, probably shot on over the gel coat as a barrier to prevent print through from the cloth that was to follow. A lot of times a coat of chopped matt is sprayed on for the same reason. The thing is that if its a glass boat and if it was ever shiney then its gel coated. I can't think of any small boat that is made out of glass that left the factory with paint over the glass, not one. In fact I can only think of one large boat builder that paints over top of glass for new boats, and you didn't say you had one by Buddy Davis.<br /><br />Thom