My 78 R100 had a poorly repaired hole in bottom of the tank. Needless to say, it was slowly leaking. I brazed a little patch over it and that’s fixed. Next, the rust and decayed factory red liner. I decided upon casewell epoxy liner, but prepping the tank first. I tried a “safe” stripper and got nowhere. Then, went with methlyene chloride. I was expecting all the liner to be removed, but it’s still “mostly” intact. I did the sloshing around with chains in the tank and a lot of gunky liner came out, but not all. Does all of the old liner need to come out before casewell liner is applied. Also, I was planning to use Phosphoric Acid prior to casewell liner. Are there any additional steps? Any chemicals/rinses between the phosphoric acid and the casewell liner? Thanks!