• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Removing Gunk from bottom of 68 coronet

dcollord98

Member
Local time
7:32 AM
Joined
Jul 31, 2013
Messages
13
Reaction score
0
Location
Delaware
I don't know the real name of it but I'm referring to the rust preventative coating the factory put on the bottom of the car. I have been grinding away at it as well as using the sandblaster for upwards of two-three weeks now and I have made significant progress but there are some areas that are proving extremely difficult to get to. Does anyone know of any solvents that are commercially available that will dissolve this stuff to get it off a little quicker? Any suggestions are greatly appreciated.
 
Not sure it was the best thing, but I found that brake cleaner was good at dissolving it on my 68.
 
I removed the undercoating from my car. I used a map torch and scraper, to start. I found what worked best, was to heat a very small area for few seconds, and scrape it off, before it cooled. Then i used the torch with screw drivers & pics, for tight spots. Then went over it with wire wheels, gas, and clean rags.
 
A good heat gun should work as well. Probably a little safer.
 
Another member here recommended a small Harbor Freight needle scaler. He was wild about it's performance.
Mike
 
I used a propane torch & STIFF scrapper. Be careful of the hot melting undercoat. I may try to ignite, but usually blows out easily, have water handy. Takes time. I used brake clean & rags on the residue. Got fairly clean but not any show quality.
 
Last edited:
My undercoating was very dry. I used various scrappers and it worked out well. No sloppy mess to clean up. Same with the inner front fenders.
 
Not sure a heat gun produces enough heat for the job at hand
It does....and especially if one that have adjustable temps.

I don't like to use anything that produces a flame since most times it's hot enough to make the stuff smoke. A heat gun can do that too but at least you don't have to worry about a flame.

And please don't use gasoline as a solvent. It's way too dangerous.
 
Small Berz-O-Matic propane torch and a 1-1/2" scraper. After that, spray on some Gung Engine-Brite
and let it sit overnight and then wash with soap & water.
DSCF8423.JPG
DSCF8406.JPG
DSCF8418.JPG
 
If you use a torch or if a heat gun gets warm enough to work, be careful of falling pieces of undercoating. It will burn your skin. As for gas being too dangerous, i used it with common sense, and a li'l ventilation. Never had a problem.
 
I did this as an experiment the past year in my collision class on my 69 RR conv. Many of the ideas already listed from above replies. I did use a two post hoist and not a rotisserie. I bought two light LED on stand for vision helped greatly. Needle scaler (went through 3 all Harbor Freight) to knock out large chunks, Used Aircraft brand Paint Stripper (aerosol not as strong as in a can), brush on in little areas, so doesn't dry out. Overhead can be messy as it drips. Putty knife (rigid type) and Wagner heat gun. I did use air chisel with large blade for areas I knew I would not damage. Used 36 grit flap disc on grinder for flat areas and wheel wells and sometimes a wire brush on a drill, and then pressure sandblast. I then finished with gravity feed blast and used razor blade and long flat screwdriver to find the small stuff. Make sure you remove the seam sealer as well as I found often surface rust underneith. Trunk pan was replaced so that saved some time. I experimented first on fender and fender rails first and because was mostly flat, paint stripper worked best there. We have huge sand blaster so finished that inside of it. Going to use epoxy primer then Raptor tint-able bed-liner to match car. Looks good in trunk. Needle scaler for majority of project but watch air pressure. Roughly 50 hours work. Wear dust mask and gloves. Took a fresh air supply from a paint hood and converted to a blasting hood for blasting purposes kept cool that way. Good Luck! School closed for virus so now I sit

DSCN1505.JPG
 
Ditto on the torch. It takes very little heat to soften it enough peel off like butter. I used plastic scrapers and some paint stir sticks shaped to fit the hard to reach areas. Cheap paint thinner and Scotchbrite pads cleaned it up to look like new metal.
I did not use a rotisserie.

20160311_154026.jpg
 
I used oven cleaner on mine and then hit it with a pressure washer after sitting for a half hour worked great!
 
I guess I like peeling it all off, sweeping it up and putting it in the trash. No fuss no mess.
Then spray it down with engine degreaser and wash. It's nice to get all of that junk off!
Of course, that's what kept it so nice for so long!
 
I guess I like peeling it all off, sweeping it up and putting it in the trash. No fuss no mess.
Then spray it down with engine degreaser and wash. It's nice to get all of that junk off!
Of course, that's what kept it so nice for so long!
I've found hidden rust once the undercoating was off and some of the rust wasn't pretty. If it was applied well and it didn't crack open, then you're good....
 
Auto Transport Service
Back
Top