I'm using a heat gun and some metal cleaner paste, but it won't come off easily. You guys have better ideas or now some nasty stuff that works?

I'm not going to use dry ice.:surprised

I'm going to put the whole underside in POR-15. But want it bare to the metal first.

I'm presuming you've already pressure washed with plain old water to remove the mud, as that is water soluble. That will have removed anything that a good shot of pressure will knock off.

Using Dry Ice on the underside would be a tedious and non productive process at this point, from what your picture shows.

Have you tried Mineral Spirits...that may go by the name of White Spirit (per Wikipedia) in Europe, or Turpentine. Both of these will dissolve the tar, so be prepared to use copious amounts of blotting agents or put a pan down and wash the underside of the car with it. You'll be down to the next layer (probably the paint or the primer) in a short period of time.

You could also try paint stripper, but in my experience stripper won't work well against tar....it takes several coatings before it will remove the stuff.

2¢

E

i used paint stripper, but that even makes a bigger mess haha

You're doing it the right way. I had a butane torch and paint scraper and about 8 to 10 hours of hot and stinky work. Liberal quantities of turps and plenty of rags gets rid of what's left.

Okay..than i have to do it the hard way. I don't mind lots of handwork haha.

There is so many rust coming from under the tar, it's amazing. I think i have found a very rusty z over here haha. If i have cleaned it all up and removed the rust. POR-15 is gone be my best friend.

I don't want new tar under the body anymore. It hate the stuff, and it seems that it atracts even more moisture/water.

I allready spent many days on the underside. So 8 to 10 hours wont be it for me .

I also used a small propane torch and a scraper. I used steel wool in mineral spirits after I got a chunk off to clear the rest off to metal. It was a long process...and messy. But it worked.

I know POR-15 has a very hard finish but I'd put some sort of stone/chip guard back on if you can. I've never used POR so I can't be sure but IIRC there is some additional prep you need to do before applying another paint over the top of POR.

At the very least, an additonal stone/chip guard paint will help deaden noise etc. Especially around the wheel wells.

Mineral Spirits, Jet Fuel, Kerosene, Diesel Fuel, Fuel Oil are all refined/distilled products of crude oil... all of them are solvents for tar based undercoatings.

Mineral Spirits are EXPENSIVE today - Kerosene would be the best trade-off between cost and effectiveness. All of them are FLAMABLE at various Flash Points... but used carefully, outside, with good ventilation you can use kerosene.

Turpentine - is a refined product from tree sap... not related to the refined crude oil products.

FWIW,

Carl B.

So what's best? Using chemical stuff to disolve the tar, or just scrape it of together with the heat gun?

For the inner front fenders and all wheel wells, I used a propane torch (heat gun wasnt hot enough) and a scraper to get the bulk of the stuff off. The I used mineral spirits and steel wool to get right to the metal. Then I used Metal Ready to etch the metal, then Marine Clean to wash it all off, then used POR-15.

Okay..thanks.