In case anyone is interested, here's a progress update.
I finished scraping off the rest of the gunk on the floor pan, which seemed to be a mixture of asphalt, bondo, jb weld & fiberglass cloth, seam sealer, and adhesive (used to stick down the carpet).
It was pretty miserable work at times, but a friend came over the weekend and helped finish it off. For posterity, here are all the things I tried:
1. Dry ice: as recommended earlier, this worked pretty well on the big areas, but I wasn't able to use it in tight corners or vertical surfaces, and it didn't work as well on the other non-asphalt coatings.
2. Heat gun + putty knife: Required a bit of elbow grease, but cut through the seam sealer/adhesive pretty well and left a relative clean finish. I mostly focused the heat on the putty knife to heat it up.
3. Mineral spirits: You can find the low-odor variant in California, which seems to work fine. This was okay for dissolving the asphalt film when it was already mostly scraped away, but not well on the thick stuff, and not so much on non-asphalt.
4. Acetone: I didn't have much success with this, as it evaporated too quickly to dissolve stuff.
5. Denatured Alcohol: I thought this wasn't available (
https://www.timesheraldonline.com/2019/ ... -nonsense/), but I did manage to find some at the paint store. . The guy at the store said they had some way of getting around it. As far as I can tell, it's the real deal (it tasted the same j/k). Either that or I'm now a rum runner. This didn't work to dissolve stuff, but I used it before painting to clean up the dirt and residue.
6. Oscillating multi-tool: I found one of these at Harbor Freight for $20. How have I not known about these until now! This is a handy tool, great at getting into tight spaces. I used a few scraper attachments, which cut through the coating pretty well.
7. Wire wheel/drill: When the coating was thicker, it just kind of smeared it around, but once I had it thinned out, it was good at removing the rest. Also, we used to to clean up pitted rusty spots.
I welded in a patch panel in the floor where a hole was rusted away. My wife and daughter helped cut out the old rusted section. I made an improvised welding spoon out of a copper pipe that I smashed with a hammer, and also used a hunk of aluminum I had around as an additional heatsink. It was a bit tricky to keep burning through, but I kept the current low and took my time:
Here is the whole thing prepped:
There are many strong opinions on the Internet how paint metal.
I ended up using Rust Destroyer (
https://rust007.com/destroyer.html), as it seemed like a pretty good all-in-one solution, and I've used it before. Here is the bottom all primed:
After giving this a few days to cure, I'm planning to top coat with an oil-based paint, then perhaps fill in some of the smaller pinholes with epoxy.
). Any other suggestions for removing this gunk?
