Undercoating

[A.Gramz]

Heat gun is just slower will work but slower good luck worst part of my restoration so far

[Aar1064]

I used Aircraft paint remover and a oscillating tool with a scraper attachment to scrape the undercoating on the inside of front fenders. It's nasty and protection for hands and a respirator should be used as I'm sure you know.

[340challconvert]

Cleaning up my front and rear wheel wells/inner fenders of the factory undercoating.
Used a Dremel oscillating tool with a hard scraper
Was labor intensive, but the under coating came off relatively easy, then used sharp chisels (gently)  and brake cleaner to clean up the residue, then DA'd with 80 grit.
Granted this was in the wheel wells only and was not the entire bottom floor, and it was still several hours worth of work for each wheel well.
In the first pic you can still see the original undercoating pattern.
Before and after pics

[nsmall]

Looks beautiful.  Now stay off gravel roads.

[340challconvert]

Looks beautiful.  Now stay off gravel roads.

Yes-time to imitate the factory coating.

[340challconvert]

Finished the front inner fenders which are now painted and starting the rear wheel wells.
Wanted to make sure there was no rust on the welded seams.
Using a dremel osculating scraper, very sharp wood chisels and wire wheels in a drill.  NO FUN, a lot of labor, but it works.
I like the heat gun idea, garage is underneath the living area of my house, so I prefer not to use a torch (car is not mobile)
This is like "torchure", and by far the worst job so far on my resto: so the torch idea is sounding more feasible (with a respirator and good ventilation) 
Some pics on the driver's side wheel well.  Seems look good so far!