This afternoon I finished removing the undercoating by removing the remaining tar residue from the sheet metal. The black coating remaining was similar to that left after I removed the coating from the floorpans above. I tried a new solvent, called De-Solv-It which is citrus-based and doesn’t have a noxious smell, though it does get to you after a while. This stuff came in a spray bottle which made it suitable for applying to the underside of the body. I bought three 12 ounce bottles ($4 each from Walmart–in the groceries section, not the paint-stripper section) and used almost all of it to complete the job.
I began with the areas underneath the front fenders. Despite the orangelike smell I put on my heavy gloves to protect my flesh and wore safety glasses.
I sprayed the area liberally with the solvent, waited thirty seconds, then agitated it with a stiff stripping brush.
Then I gave it another coating of solvent and then wiped the residue off using a shop towel. The surface came pretty clean.
I determined I could work relatively large areas at a time in this manner.
I started on the underside, going to the driver’s side first. I worked the entire floorpan area in one pass.
Here is the rear section of the floorpan, before and after.
Then I did the passenger’s side, and moved on to the transmission tunnel.
Here is the passenger side.
Next I proceeded backwards toward the rear, under the rear shelf and the trunk area. I sprayed, waited, scrubbed, sprayed, waited, and wiped.
The sheet metal came pretty clean using this method.