removing undercoating

[Ryan Clark]

I am in the process of removing the rear suspension on my '65. All that is left is to remove my trailing arms, which will be done tonight. While my trailing arms are being restored at Bairs and the rest of the suspension is out, I plan to clean up as much of the underbody as I can. There is undercoating on everything. It is on the frame as well as the fiberglass, especially in the rear wheel well area.

There has been discussion on cleaning undercoating off the frame, but what can I do to remove the undercoating, and road grime, from the fiberglass under the car and in the wheel wells.? Should I use Simple Green and a good stiff brush?
When done, what should the underside look like, should it be basically bare fiberglass? Or was something done to the underside?

Thanks
Ryan

[Bob R.]

Re: removing undercoating

The undercoating on your car was factory installed. It can be removed with a heat gun and scraper. I have also washed it off using gasoline. The gas breakes it down quickly.

[Wayne C.]

Re: removing undercoating

I concur: heat gun, scrapers, plus oil-paint thinner or spray can of brake cleaner to get the residue. Messy, so protect the floor with plastic sheeting and have lots of paper towels available..

[Patrick H.]

Re: removing undercoating

Ryan,

Your car sounds like it may have a little more undercoating than what the factory installed. I know in talking with the guys who worked at our local dealership years ago (in Mich) that undercoating was often done even to Corvettes to "protect the frame" (and to pad the dealer's pocketbook).

Eastwood makes a new product to remove undercoating. You might give it a try. It sounds easier than heat.

Patrick

[Duke W.]

Re: removing undercoating

NEVER use gasoling as a general purpose degreasing solvent. Use paint thinner.
Gasoline is highly flamable and you run a significant risk of starting a fire.

Duke

[Mike Geary]

Re: removing undercoating

Ryan: My '65 was originally a Minnesota car and the entire underbody was caked in undercoating. It now looks so pretty that I sometimes crawl underneath just to admire it. The process: use the heat gun to soften the stuff -- be patient, let the heat do the work. To scrape it off, I used a hardwood kitchen tool similar to a wide putty knife. No risk of gouging the glass, plus the edge could be kept sharp by sanding. The best solvent I found was kerosene. Dissolves the undercoat really well, isn't dangerous like gasoline, can be misted on using a plastic spray bottle, and won't wreak havok with your skin, eyes, lungs, etc.
Lastly, the brown scotchbrite pads are best for getting the last, stubborn deposits off while preserving the glass. Messy job, but not as bad as paint stripping! Mike

[Gary C.]

Re: removing undercoating

Please never use gasoline for cleaning. It is just too dangerous.

Should you ever consider using gasoline as a solvent I would invite you to pause first and tour a local or regional burn unit. If it is of any significant size there will likely be some poor soul in there who had a bad experience with gasoline. Terrible accidents happen when gasoline is around. As one who has spent some time in burn units, it is not pretty.

[Ryan Clark]

Re: removing undercoating

Paint Thinner, or similar solvents, won't hurt the fiberglass?

If I clean off the undercoating that is there, should I then reapply some sort of protection to the fiberglass?

Thanks
Ryan

[Duke W.]

Re: removing undercoating

No, paint thinner won't wont hurt the fiberglass. Even acetone won't attack cured fiberglass. As mentioned previously it sounds like you have aftermarket undercoating. The plant only sprayed it in the fender wells for acoustical damping.

The heat gun is probably the best way to start, then wipe off the residual with paint thinner. There was no specific coating the the bottom of the fiberglass floor pan, but they typically have some blackout and undercoating overspray.

Duke

[Ralph E.]

Re: removing undercoating

Patrick, Is the Eastwood product called "Under Gone Undercoating Remover"? If so is it safe for fiberglass. Do you know how it is applied. Have you tried it? How messy?

[Patrick H.]

Re: removing undercoating

Ralph,

Yes, that's it. Other than that, I don't know a thing about it. I'd call Eastwood if you're interested. It's just that spray-and-wipe sounds a lot easier than heat-and-scrape.

Patrick

[John H.]

Re: removing undercoating

I've used Eastwoods Undergone on my '64. You get the undergone undercoating remover and undergone degreaser. Both are aerosal sprays. The stuff works pretty well but depending on how thick things are you'll need 3, 4, 5 cans of the stuff. I ended up using a heat gun to get most of it off then the undergone to completely eliminate it. It did not harm the fiberglass at all.