My '57 tank had enough rust that I didn't want to run it .
I treated it with Wood Bleach ( Oxalic acid ) and it truned out right .
I did not use any sealer after that^ .
I have used RedKote on my 'Swiss cheese' 1989 Yamaha XT 350 gas tank , which turned out good .
RedKote is fairly 'runny' . Enough so that I think it would run through the holes at the top of the tank divider .
Sure , it would take a bit of patience , but ...
I think that^ because I drained the excess RedKote out of the XT tank through its petcock mount hole . That hole is about 1/2" x 1 1/2" or less , which seems smaller than some of the hols in the divider .
RedKote can be thinned slightly with MEK or acetone .
Pete .