Undercoat removal is a bitch.

I'm still not sure whether what I am removing is factory undercoat, or something applied on top of the original undercoat. In places like the back of the door lock striker plate, the very top of the wheel wells where body meets frame, and near the torsion bar cover it is very thick. My arm is sore today from spending about 3 hours last night working on it with my putty knife.

At the start of my undercoat-attack yesterday I tried a suggestion I had read about from several sources: application of thick paint stripper to the undercoat. Maybe it worked for those people, but for me, it wasn't helping much. And maybe that is because I have so much mud and grime caked on top of my undercoat, or for some other reason, but the heavy duty Zip Strip wasn't really making an appreciable impact.

What to turn to? Another suggestion was to use heat. I've heard enough about the negative aspects of heat on body panels (namely, potential for warping) to be careful. I used my heat gun to heat the stubborn areas until I could just see the thin parts of the undercoat starting to melt.

Then I stopped and scraped. The coating was much more pliable that before heating and easier to remove. It still leaves a tar-like residue that I hope to be able to clean up with paint thinner or turpentine, but I think this is the only way I'm going to be able to finish the job by hand. I haven't used a sand blaster before, but I really don't understand how a blaster would be able to remove this stuff. It has too much "give." Perhaps someone can enlighten me. In any case, I have the majority of the gunk removed from both rear wheel wells. Getting at the stuff behind the engine tray on the inside rear of the body is going to be pretty difficult. It may be easier with the engine out. I hope to get the engine out in the next few weeks.