Removing undercoating?

I used a propane torch and Putty knife for the main part then sprayed WD40 penetrating fluid and wire brushed it. Wiped it down then heated fairly large areas at a time then wire brushed the remainder which comes off like a powder residue, so you just sweep it away, and all is completely clean and looks awesome. Wire brushes were hand brushes not drill type attachments. They clog up but you can buy packages of them at the dollar store and toss them when they are used up. I won't candy coat this what ever way you do it this job sucks, and you'll be thankfull when done!