Undercoating

[hopsBB]

Does anybody happen to know what kind of undercoating Studebaker used?Reason I'm asking is I just took off one of my fenders to work on it some and whoever(if it was Studebaker) put some for real stuff up underthere.It looks more like roofing tar than anything else.Some of this stuff is atleast 3/16 thick.Anybody got any tips on getting it off.I been grinding away getting all the loose off and I'm seriously thinking about just leaving it on.Its so thick that I can't get the bolts for the headlight holder thing out.(I don't know what the actual name is)

[Welcome]

What model year is your Stude???

[N8N]

usually it dries out and you can just scrape it off with a putty knife and then wipe the rest off with kerosene. Sounds like you got some of the stuff that actually stuck...

nate

[hopsBB]

Cars a 59 4dr Lark.I don't know what this stuff is but I've tried grinding,sanding,chiseling and it don't move.Some of it came off pretty easy but the rest is seriously almost as thick the bolt heads.Somebody went way over board.

[jnormanh]

Roofing tar is just about what it is. After all these years it has oxidized and hardened, but you may be able to soften it enough to scrape off with a heat gun. Not your wife's hair dryer, but a genuine industrial heat gun.

It's original purpose was more for sound deadening than rust proofing. A decent coat of zinc chromate paint, or aluminized wax would have been way more effective against rust. Or they could have used galvanized steel for another $20 per car, and they would have lasted almost forever - but nobody else did either until Porsche about 20 years ago.

[rockne10]

What has hardened and not correctly adhered to the steel can be chipped off. What has correctly adhered can be heated and scraped off. Final cleaning can best be done with kerosene/diesel fuel and rags, then final clean or prep-sol to prepare for paint.

[COMMANDERPINK1]

What has hardened and not correctly adhered to the steel can be chipped off. What has correctly adhered can be heated and scraped off. Final cleaning can best be done with kerosene/diesel fuel and rags, then final clean or prep-sol to prepare for paint.

This works very well, use like a heat lamp or a heat gun.
Tom

[Jim B PEI]

Even galvanized steel is not proof against a design mistake. I own one of the legion of VW diesels (a Jetta) with the VW replaced front fenders. Seems putting sound deadening material over galvanized lead them to loose paint/rust in exactly the same place, in other than a desert climate. Oops!

[Milaca]

Asphalt undercoating? I scrape it off with a large flat blade screwdriver. I use a small flat blade screwdriver for scraping the bolt heads clean. As for galvanizing, that gets stone chipped through and then it rusts underneath. At least the asphalt undercoating doesnt stone chip when its applied thick.

[Welcome]

Cars a 59 4dr Lark.I don't know what this stuff is but I've tried grinding,sanding,chiseling and it don't move.Some of it came off pretty easy but the rest is seriously almost as thick the bolt heads.Somebody went way over board.

IF ..what you are dealing with was in fact "Factory applied," it would be:

Trade name: INSULMAT
Stude p/n: KFD8809
Supplier: Mortell Company
Supplier's product number: 2071

[zoegrant]

Carefull scraping off undercoating

Hi...I have found that the best way to remove the undercoating is with the use of a heat gun and scraper.....if you dont let the gun heat the undercoating to make it soft you risk doing damage to your elbow through repetative motion of trying to chip it off...LET THE HEAT GUN WORK ITS MAGIC...I am siiting here typing this with my right arm in a sling due to not letting the heat gun soften that tar like material where I could just push the scraper thru it...now my project is on hold for at least a week or two...John

[R3 challenger]

The undercoating applied by Studebaker varied tremendously in thickness. Nelson Bove recently weighed three 1964 Lark-type dual headlight fenders. All three had paint and no body filler. The one without any undercoating weighed 30 lbs. One with a moderate amount of undercoating weighed 37 lbs, and the heaviest one (which had a ridiculous amount of the stuff) weighed 51 lbs. Also, from my work in scraping/chipping it off the Plain Brown Wrapper, I found that some areas hardly had any undercoating while other areas had a very thick layer. Most of it was hardened. The best technique for removing it will vary, depending on how dried out it is and how thick it is. A heat gun, chisels, flat-bladed screwdrivers of various sizes (sometimes with hammer) and other methods were used at varous points.

Good luck; there aren't too many things you can do to a Studebaker that are less fun!

George

[woodysrods]

Heating and scrapeing is a good method, but if you are impatient and careful. Use an air chisel with a flat blade at a real flat angle so as not to dent or puncture the metal. This works best if the undercoating has hardened. The vibration from the air chisel makes this stuff rain off of the underside of your floors. Sometimes in large sheets. I know it sounds risky but it is easier than you think!
Good Roads
Brian

[Warren Webb]

I would also recommend wearing a quality resperator. Back in the day undercoating was made with asbestos, so wearing a resperator will be a safe investment for the future.

[hopsBB]

Got a heat gun from a friend of mine.Its not an industrial one or anything,I think its one they used to take down some wall paper or something.It still a slow go on the thicker spots right around the headlight assembly,but I did finally manage to get the bolts out.Some areas I just can't get to the go though,like right above the headlight.I'll keep trying though seems to be better than anything else I've tried.Been working on it for hrs now.