Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tunnel

[Roger D.]

Folks:

I'm still in restoration of my '72 Coupe. The under body of the car was mostly dirty of road dirt/grime and was easily cleaned.
What I haven't gotten to yet is the drive train "tunnel", i.e., fiberglass directly adjacent to the transmission and differential which has a layer of grease/oil.

What should I use to clean those areas?

Thanks in advance.

Roger

[Bob R.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

When I cleaned the underside of my 63 I only cleaned where I could reach. Eventually I had to remove the transmission for service and cleaned that area at that time and I lowered the rear to replace the bushings on the rear cross member and cleaned that area at that time.

[Carl N.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Mixture of simple green and water. I hook up hose to hot water heater in the shop and hit it with hot water. May take several applications. If really stubborn preheat carefully with old hair dryer.

[Eric J.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Roger. I have used simple green and it works, but now I use Purple Power. Small plastic brushes and a flexible putty knife with the corners ground off/rounded. Lots of rags. This is something that there is no quick way. I just did the tunnel on a 62 this way. I got it up in the air and went to work. Put plastic down if your floor isn't epoxied.

[Alan S.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Hi Roger,
I bet you'll be surprised at the good condition the surface of the fiberglass is under all that 'gunk'.
The mixture of oil and road debris is often a pretty good 'preservative'.
I agree with the use of something like Simple Green and also with Eric's suggestion of a plastic putty knife with the corners rounded off. The less you scrape up the surface as you work the better the appearance of the fiberglass will be.
Regards,
Alan

[Eric J.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Roger yes I am always surprised as well, gear oil is like cosmoline for fiberglass.

[Roger D.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Simple Green it will be then! Thanks for those suggestions. I've used Purple Power before and know that it isn't good on paint (the garage floor is painted)

Roger

[Bill L.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

One suggestion if I may having just cleaned the underside of a 70. Try using the bondo plastic applicator first. You can cut them to various sizes to get in cracks and crevices. Work in a small area at a time. Even the plastic putty knife can scratch the fiberglass a little.

Lacquer thinner works very well to get some of the residue off. You can use a grey scotchbrite pad but with little pressure because it too will scratch the fiberglass. If the fiberglass does get scratched try some VERY light pressure and a little meguiars scratch remover if it is bothersome.

Bill

[Patrick H.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

I've used kerosene with excellent success, and if there's no paint around then using AutoZone brake cleaner to degrease it when I'm all done. For the kerosene I usually use one of those generic parts cleaning brushes that looks like the one you used in kindergarten to paint with, but a lot larger.
So far I've prepped a few cars in this manner and they look great. The AZ store brand of brake cleaner seems to work better and affect paint far less than other brands. It doesn't hurt that it's less expensive by a little bit.

Patrick

[Edward J.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Roger, Its a very messy job some advice, if you want to keep the floor some what clean use an old tarp and lay on the floor to catch the grease. using a plastic scraper first is the first step on the fiber glass. then I would advise using some rags with mineral sprits it will remove the grease, undercoating, and will not harm any finishes, be careful with anything like lacquer thinner, brake cleaner if it gets on any painted surface on the car it will damage the paint( floor also). I have done this method a few times over the years.

[Kevin G.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Here's a after shot of my LT 1. Hours and hours were spent cleaning it's belly. I don't have the same undercarriage before picture but it was pretty bad.....There's a chassis judge here that might remember how dirty it was. The only products I used as the above posters suggested to me years ago was a warm Solution of diluted Simple green. Followed by a complete coating of CRC SP 350. I'm not sure if the aerosol cans are still available but I found it at Grainger at the time.

[Alan S.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Hi Kevin,
Pretty nice CAMERA work on your part in creating that picture!!!
It appears the diluted Simple Green doesn't remove the dents from the front saddle.
Might full strength Simple Green do the trick?!?
Regards,
Alan

[Duke W.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Mineral spirits, also known as paint thinner. Kerosene, which is like diesel fuel leaves an oily film. Mineral spirits doesn't. IMO Simple Green isn't worth a damn at dissolving petroleum products compared to mineral spirits, and mineral spirits won't attack cured enamel of lacquer paint.

Be careful. I've run across some "paint thinner" that appears to have water emulsified it it, which eventually results in a cloudy white substance that doesn't work very well as either an enamel paint thinner or petroleum solvent. Don't buy anything that says "environmentally friendly" or similar nonsense. It's probably the watered down junk.

Duke

[Rich C.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Here's a after shot of my LT 1. Hours and hours were spent cleaning it's belly. I don't have the same undercarriage before picture but it was pretty bad.....There's a chassis judge here that might remember how dirty it was. The only products I used as the above posters suggested to me years ago was a warm Solution of diluted Simple green. Followed by a complete coating of CRC SP 350. I'm not sure if the aerosol cans are still available but I found it at Grainger at the time.

Wow, Nice Job!!!

Curious as to the CRC, what was that product? Is it a protectorant of some kind?


1973 LS-4 454 coupe owned 24 years
1996 LT-4 CE coupe
Victory Hop Devil IPA-currently on tap!

[Don H.]

Re: Corvette Body Restoration - Cleaning Grease/Oil from Fiberglass in Drive Train Tu

Google CRC SP350 or CRC SP400 and you will see green aerosol spray cans of industrial rust inhibitor. It is a lighter version of old cosmoline.
I sprayed it on bare metal camber strut rods, half shafts, front springs, anti sway bar, etc. Good stuff.