My running boards have some sort of undercoating on the underside of them. How can I strip it to prep for painting?

Looks like it was brushed on. It's holding well and not rusted underneath. Probably should have left it, but I've started stripping it so I guess I gotta finish it.

Does anything work faster/better than what I am using ...

Klean-Strip 10-min "Strip-X" to melt it. Then scrub with a brass or steel brush. Wash and scrub more with gasoline. I found that a little kerosene in the gas will slow evaporation. Using a lot of paper towels. I will probably lightly sand blast it after the coating is off.

Can't seem to remove all of it at the joins where the supports are attached.

Looks like both sides of the boards were painted with red primer before painting and/or undercoating.

Here are some work-in-progress pics:
> Underside stripped vs orig
> Underside close partially stripped vs orig
> Underside coating close up
> Top partially stripped vs orig

Thanks for your help,

- Lonnie
My '54 3104
Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post.
lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt.

OLD STUFF ... houses, furniture, cars, wine ... I love it all