Technical Painting a fiberglass car?

Educate me. Based on a TV show I saw 20 years or so ago, they pulled a C2 Vette out of a garage to restore. I think it had been sanded down then forgotten about for 35 years.
The guy doing the work on said he had to keep putting gel coat on it, as it kept getting absorbed by the dry body.
Maybe it wasn’t gel coat? Is there something else that was used?
Like I said was 20 years or so ago, so I might be mistaken.

 

Epoxy primer is also suited for fiberglass, not just bare metals.
I’m seeing newer epoxy primer surfaces and fillers used. The ones I’ve used are still not as heavy bodied as polyester or gel coat.

 

Hey, 54;
Thanks for the slam. You are the current resident bodywork professional?
I admit it. Just a hobbyist. I don't & won't do it for a living. I comment on some things I found out for myself.
Marcus...

 

That’s how I understand it. Poly over poly.

 

Because of superior bonding strength & strength of material ( plus it " wets out" cloth/ matte better , epoxy resin is preferred in the boating industry , especially in repair work . It is however more costly .

 

Let’s not confuse marine or submersible products with fixing an old car.
Not the same

 

Restoring vette's at Corvette's An Performance for 16 year's on off, We would strip with aircraft grade stripper, Tal-strip, 3-m 80 grit, v-out all seams, Resin gel, filler, block, An use a sprayable polyester resin called Sandy, Block again Light 80, 150,220, 320 with guide coats..
The shop's been doing it this way for 40 yrs. Many conqueror's winning car's

 

I have used Clausen polyester once.
Liked it.
Plan to use again

 

I have considered commenting on this thread a few times since my dad painted lots of vettes in the 70’s and I painted lots in the 80’s and 90’s as well as several parts I built from scratch from glass. We both chemically stripped most of the cars to bare glass and neither of us have ever put gel coat on prior to paint. Anyway, apparently nothing we did will work even though I have seen cars 30 years later that I painted that still look great.

 

Nope.
Gel coat isn’t a must do.
only a preference for some. It’s just like the filler over bare steel or epoxy debate.
Like any paint product, using it correctly and consistently is what’s important.

 

Yep, I’m just kidding around Anthony. I know there are best practices. I just apparently never used them.

I honestly love working with glass more than metal. But, I also know that is weird...

 

By my post I was in no way trying to say to the original poster he could not do this. But I do think as far as fiberglass is concerned, new fiberglass and old fiberglass is different, Back when, we would strip the fiberglass of paint, Corvettes , then use DP-40 which is now DP-90 I assume. The only difference between 40 and 90 was the 40 had an induction time of 30 minutes before spraying. Either way, we would shoot the car with DP and wait 30 minutes then prime it, However many coats. the DP was still tacky. The primer would bond with the DP. We would always let the primer cure for a month or so. Stick it in the sun was always the preferred method. The difference between a good job and a great job was always patience. I know those of you who have done cars that were standouts understand what I'm saying. To the OP, get as much paint off the original car as you can, Then spend as much time as it takes to smooth the body finish. Then prime and finish the car. But you may not want to put this much effort into it. If not, sand the bad spots and do like the last guy did. I may have gone too far with my comments. Lippy

 

I was the vette guy at the collision shop I was at.
Gluing them things together was easy.

 

X2 on allowing a primer to cure for a few days.
Let that stuff shrink as much as possible before ya sand it

 

Yes, you are weird Jeff lol... fiberglass is for fixing rust holes in metal, everybody knows that

 

Why is there a difference , they are both molded fiberglass shells ?

 

The stuff designed for your car isn’t submersible but…
Plenty of folks paint boats with car paint.
lot of Emron has been sprayed on em
boats that generally stay on a trailer or lift is fine
But for something that stayed in the water, I’d prefer marine designed products.
Most marine top side paints are non skid. Like big fishing boats or yachts.

 

Hey, Anthony;
Out of curiosity,
Is hull paint somehow denser/slicker/harder to resist effects of constant sun degredation, or sliding on sand, salt water, or preventing barnacle attachment - or somesuch? I always understood Imron was designed for aircraft, mostly to deal w/the sudden air temp changes, & to provide a very slick skin surface. ???
Marcus...

 

I’m no chemist.
That’s a question for them.
All these resins come from the same plants. Then paint companies modify them for whatever .
UV protection, hardness, elasticity, gloss level……..
I restored a church baptismal, they keep it filled 24/7. Has a salt water seat up now.
The old chlorine set up ate the old finish.
Researching material to spray in it I would read tech sheets for automotive paint that would say not submersible. Warranty reasons?
Possible. Used an epoxy designed for marine use. Looks great but I wouldn’t use it on a car if you wanted high gloss or something you can buff easily. I’d use it on the chassis
Is marine paint rebadged car paint? Some is possibly.
But I’m leaning to hull paints being less porous and harder. But hull paints have chemicals that resist (poison) critters attaching to the hull.
Some are designed to “self polish” as it moves through water. Again, paint companies tweeking resins.
Most marine paints on large boats, not bass boats, look lees deep or not as glossy as car paints.

 

Thank you.
Marcus...

 

Try scraping the paint off with a razor blade scraper. No kidding, it does a good job with no chemicals and minimal danger of damage once you develop the knack. This shouldn't take long and then the process goes fairly quickly.

 

Can't say in all cases, but of the Endura Epoxy I used, the marine grade had a greater percentage of zinc chromate, went on thicker, and subtle change to mechanical properties. For instance Impact resistance.

 

Id really enjoy the explanation stating the characteristics of " non submersible " fiberglass.

 

Me too.
You’re welcome
But if you plan to keep your vette in or under water you can apply marine paints that have chemicals that deter the formation of marine life and/or “self polishes” as it moves through the water.

 

You are are the one forwarding the theory , its incumbent upon you to clarify ...
Or just forget it ..

 

Just discussion.
I’m curious and learning as we go
What makes a paint or primer have “marine” on the can? what makes em waterproof but not submersible?
I don’t buy the theory that it’s all the same just because the resin comes from the same plant.
BBQ meat comes from the same sources but taste different depending on who cooks it.

but the guy just wants to fix an old glass car.
I’d suggest sanding the damaged areas to see whats on the car.
Then go from there.

 

Come on man, read what was typed. He's talking about paint products, not fiberglass.

 

This works well. My OT 69 Vette is totally stripped right now. About 80% of the 40 yr old repaint (feather fill, lacquer primer, and lacquer topcoat) was peeled off using a razor and a heat gun. The heat gun is used to warm the paint ahead of the blade so it will peel off in long strips rather than chipping off in a bazillion tiny pieces.

Razor stripping is really advantageous when a car has multiple previous repaints as you can strip all layers in one pass while sanding or chemical stripping are one layer at a time processes. It works best on fairly flat surfaces like hoods, tops, door and fender sides, etc, and these are the same areas that are most time consuming to strip by sanding as the heat from sanding on flat areas wants to soften the old paint just enough to clog the disc pretty quick.

A Titan long handle razor blade scraper is the tool most used for this. Available on Amazon for about $10 or at O'Reilly Auto for about $12. I found a heat gun with adjustable heat works better than the one or two temperature models from HF. About $40 at Ace Hardware. I used less than a dozen blades to do all my stripping, and most blade changes were due to breaking a piece out of the edge of the blade. The blade works in this application because it's thin rather than having to be razor sharp. And of course the process creates no dust so you don't have to contend with a dust mask while doing the work.