Gelcoat

[Impatient '71]

So, I've been thinking about using Gelcoat instead of paint for my 1972 satellite due to the durability of gelcoat, but have not been able to find anything regarding gelcoating a steel car. Does anyone know if you can gelcoat steel? I plan on getting the car blasted and epoxy primed and after messaging Bladecutter about his filler secrets 101 think that I will be using fiberglass filler as my filler material. If anyone has done this have they run into any problems using gelcoat? Other than the increased work of getting the gelcoat sanded and buffed is there any other downside? Any help is greatly appreciated!

 

[slimt]

So, I've been thinking about using Gelcoat instead of paint for my 1972 satellite due to the durability of gelcoat, but have not been able to find anything regarding gelcoating a steel car. Does anyone know if you can gelcoat steel? I plan on getting the car blasted and epoxy primed and after messaging Bladecutter about his filler secrets 101 think that I will be using fiberglass filler as my filler material. If anyone has done this have they run into any problems using gelcoat? Other than the increased work of getting the gelcoat sanded and buffed is there any other downside? Any help is greatly appreciated!

I don’t think it will work . That’s a process that’s used prior to fibreglass that would be in a mould. Eg boat bottoms

 

[1967coronet440]

@eldubb440

 

[Photon440]

I wouldn't do it. Gelcoat is basically colourized resin and is meant to be used with fiberglass or on wood. It usually goes down first in a mold, then layers of fiberglass go on top - if gelcoat is applied on the outside like paint, it will never surface cure and will remain sticky unless air-dry wax is added, or PVA is sprayed while it cures because air inhibits the molecular cross bonding.

It isn't meant to be applied to metal, the lack of reinforcing structure (like fiberglass or carbon-fiber) mean that it is going to be brittle, and the different rates of expansion compared to steel when the sun hits it or it gets cold will guarantee cracking.

 

[flypaper]

I have to ask why?
it will not protect your car like the proper materials would
and it sure would be a expensive experiment to your car to find out
you are not going to make a better wheel if that is your angle.
your fiberglass filler idea is not a good one
they make specific products for use as a metal filler for a reason...
so why would you waste the effort ,time and money?

 

[Jerry Hall]

I've been thinking

That's seems to be a dangerous thing in this case. I've pulled some good ones with putting to much into thinking, but this has never crossed my mind.

 

[vintage chromoly]

I’ve done quite a bit of work with gelcoat and thickened fiberglass resin.
The boat in my signature pic has a gelcoat bottom (running surface that’s under the waterline) I made a rotisserie and flipped the boat and re-gelcoated the bottom. The reason being, is that gelcoat holds up to continual contact with water better than paint.

The sides and deck of the boat are painted in PPG concept and 2021 clear. The reason being, paint is a much better product for UV protection and quality of finish.

There is absolutely no upside to using the incorrect products for the job at hand.

Also, as has already been said, there is no reason to thicken resin and use that in place of today’s fillers on a metal substrate.

 

[YY1]

If you like Bass boats.....

 

[YY1]

....or carnival midway rides.

 

[eldubb440]

@eldubb440

I have no idea

 

[PurpleBeeper]

I happened to know quite a bit about gelcoat. It's a polyester resin & as others have mentioned, it is usually used with glass fiber (or carbon fiber). It can also be used as an industrial paint.

As far as using it as a "car paint", the three main problems I see are:
1. It's not nearly as smooth, so your car would have a lot of "orange peel"
2. It does not hold up well to sunlight (UV-light)
3. As others mentioned, it is very brittle, so a minor "parking lot ding" may crack off a large section.

 

[Johnpat]

Not something I would do,if it was a good idea
restoration shops would be all over it

 

[slimt]

You want a thick direct to metal finish use aue370 from ppg if they can mix it. Other wise to it properly even if it takes longer to do.

 

[Impatient '71]

Thank you for all the replies. After all your insight I guess I'll be sticking with paint.