doing it yourself is a long process....trust me.
I just got done putting a liner in my tank, as well as priming the outside. I used electrolysis to get the worst of the rust & crud out, then swished a gallon of phosphoric acid around inside until it was shiny clean...then installed a red-kote liner.
Hindsight being 20/20 I'd either take it to a radiator shop, or just buy a repo tank...
Unless you have very little $$ and lots of spare time that's the route I'd go....then again I learned ALOT in the process. I don't know how readily availiable your 46' tanks are, but I could buy a repro tank for about $160. I probably spent $80 coating mine...
