Undercoating

[Lenn Nelsen]

Anyone have any ideas for removing undercoating?

[Chuck R.]

Re: Undercoating

There's been alot of talk in prior posts regarding this.

Simple Green, laquer thinner, enamel reducer, etc. etc. etc.

There seemed to be pros and cons on all of them ranging from Simple Green being slow to work but user friendly to the thinners (though they worked quickly) was volital, had fumes and soaked into the glass.

Give the archives a try.

Chuck

[Terry F.]

Re: Undercoating

My opinion....if it is asfault bases like the original stuff, start by using a hot air gun and a putty knife (with a grinder, round the CORNERS of the putty knife so they won't gouge the fiberglass). This process works very well. Work in a small area and keep moving. Goes pretty fast and the results are nice. You can sweep up the mess because it just falls to the ground in little chunks that get hard again as they cool off. After everything is cleaned up, I use laqure thinner and lots of paper towels to get the faint remains off. It's not so bad a job as long as you can keep it under control. Terry

[Ryan Clark]

Re: Undercoating

I have been removing some of the undercoating from my frame while trying to clean things up.

It kind of depends on the thickness of the undercoating. I have been using a heat gun and razor blades to scrape off the heated up undercoating. You just want to make sure to work on small areas and keep the heat away from the fiberglass.

Once I get the majority of the undercoating off, then I go to simple green and a coarse wire wheel on the frame.

Ryan

[Al S.]

Re: Undercoating

Kerosene breaks it down well, not "as volatile" as thinners won't hurt the paint and fiberglass like thinners or acetone. You can get the less odorless stuff also.
I believe they referred to the higher purity kerosene's as "Rocket Fuel" back in the early days of the space program. Always be careful if you know what I mean.

[Dave S.]

Re: Undercoating

Lenn,
I'm just completing removal of some undercoating and without question kerosene has worked the best. I tried lacquer thinner and paint thinner and it is to aggressive and evaporates to quick. Also tried a product called "Undergone" purchased from Eastwood which was a disappointment. Use a spray bottle and use light coats so you don't make a "dripping" mess and carefully scrape or wipe it after is sets for a few minutes. In some places kerosene soaked rags makes it a bit quicker. The only thing that works on the frame is a heat gun as it is asphaltic based paint and kerosene will remove the paint. If you are careful with the heat gun, scraper and some simple green you can preserve a lot of the frame paint. If you take your time the finished product will look almost "as new" as it has been protected since the undercoating was installed. Good Luck and be patient

[Jace H.]

Brake Parts Cleaner

Brake parts cleaner worked for me. Just have to make sure you are working in a well ventilated environement. Putty knife and LOTS of elbow grease. Good Luck.

Jace Holt

[Greg S.]

Re: Undercoating

Easy off oven cleaner. Spray on, let it penetrate for 10-20 minutes. Scrape off with a putty knife. Really loosens up the undercoating so the scraping is relatively easy. Use rubber gloves. Works great without the smell or danger of kerosene.

[Mike Geary]

Re: Undercoating

Len: My '65 had a THICK layer of undercoating on the lower body surfaces. Removing it was probably the nastiest process of the whole restoration. But you've gotten some great advice from the Forum on using a heat gun and scraper to take off the bulk of the stuff (be patient and let the heat do the work). Then as Dave said, spray on KEROSENE, let it do its job, and then wipe with paper towels. Take a scotchbrite pad to any stubborn spots.

The very last amount of residue can be taken off with kerosene, mineral spirits or lacquer/enamel thinner. But kerosene is so much more friendly to the skin and lungs --I don't know why you'd use anything else.

The payoff is worth the effort. Too bad it's not more visible!

MAG

[Gary S.]

Re: Undercoating

I would be REAL careful with Easy Off oven cleaner. It is a very strong alkalai and will cause burns just like an acid. I can't imagine that it would be any good for the fiberglass at all. Read the container and see how many warnings etc there are.

This would be my absolute last choice of a remover next to say a flame thrower.
Gary

[Terry F.]

Re: Kerosene

I prefer laqure thinner because it does not leave an oil residue. Kerosene will stick around longer and can penitrate the fiberglass, cracks, loose strands, etc and leaves an oil residue which is bad for fiberglass. Laqure thinner is pretty safe on fiberglass as long as you don't over do it. You can work small areas with a paper towel. It evaporates completely. Acetone is probably the worst, it can soften resin and takes a while to evaportate out of the resin once it gets into it (in my opinion). Acetone is recommended for clean up of resin. It desolves it pretty good and softens it pretty good.

[Donald M.]

Re: Kerosene

I, too, have found lacquer thinner to work great on fiberglass. I used it to remove layers of black paint from the fan shroud of my '67. Wearing rubber gloves, I scrubbed it with steel wool dipped in the thinner. I flushed the area with water often. Do small areas at a time. Just be careful about using lacquer thinner (ventilation, flammable, etc.)

[Todd H 26112]

How 'bout GoJo?

or similar liquid hand cleaner?

[John M.]

Re: Undercoating

I have allways used mineral spirits (paint thinner). It will not evaporate quickly like lacquer thinner and is not hard on the hands or lungs. It keeps the undercoat damp long enough for it to start to disolve it so that it can be scraped off. Follow up with some simple green and a scrubbie pad and it looks like new!

Regards, John McGraw

[Jon S.]

Re: Undercoating

John,
Would mineral spirits (paint thinner) also be better than lacquer thinner in removing black paint from the underbody?
Regards, Jon