This morning I scraping the tar undercoating that remained on the insides of the front fender panels and inside the doors. The undercoating was originally applied to protect the metal surfaces from rocks and road debris and, in the case of the doors, to provide some noise reduction.
I removed the undercoating the same way I removed it from the underside of the body, by heating it and scraping the bulk of it off, then using a solvent to remove the remaining residue to reveal the clean metal underneath. I began with the doors.
Most of the undercoating was behind the opening and on the outer door skin. I heated it with my heat gun, set on high, for about ten seconds.
Then I scraped the covering with my small metal scraper. I removed the lower half of the coating first.
Then I rotated the door 180 degrees and went to work heating and scraping the upper area.
After about fifteen minutes I finished and repeated the process on the other door.
The insides of the front fenders were also covered in undercoating.
I started along the rear edge of the fender, heating and scraping.
I worked on the lower edge, revealing a considerable amount of rust in the sheet metal. This is a typical problem area in these cars.
Then I worked my way up the rear portion of the fender. The material was actually much easier to remove where it was thickest.
Then I scraped along the middle of the fender towards the front.
Here is the front of the fender before and after I removed the undercoating.
Here is the fender finished. Each fender took around an hour to scrape–the headlight areas went fairly slowly.
In order to remove the remaining tar residue I used more of the De-Solv-It citrus solvent that worked so effectively on the underside of the body. I sprayed the tar-covered areas liberally and allowed around 30 seconds for the solvent to soak in. I did the doors first.
Then I scrubbed the area with a stiff stripping brush, following that with a preliminary wipe with a rag.
Next I made a second application of the solvent and wiped the metal clean.
Next I moved on to the fenders. I used the same process. First I sprayed the inside of the fenders.
Next I scrubbed and wiped away most of the tar.
After another application of solvent and a final wipe with a clean rag the fender came clean.