I am working on this 1945 Coleman 523 and have most of it taken apart. Looking into the tank, it has rust in it. How much can be allowed? Or shall I try to remove it, the rust, and use tanksealer?
TRY SOME EVAPO-RUST FOR A DAY. IF THE RUST COLOR IS NOT GONE THEN IT IS RED PAINT USED TO COAT THE TANK DURING manufacture. i HAVE SEEN THIS MANY TIME BEFORE. SORRY FOR THE CAPS. IM TIRED.
I don't think the red fount coating came along until well after the 520. There are several methods for dealing with rust in the fount. The Evap-o-rust is a good suggestion, although my experience is that it will need more than a day. Any of the chelating rust removers will work. You can also use mechanical methods, i.e. drop some small screws and nuts in the fount and shake vigorously for several minutes. Once you have removed the rust examine the dried fount. How bad is the pitting? Are there pinholes in the base plate? If so the the fount needs replaced. If the pits are less tha half the thickness of the base then you are probably good. Your photo doesn't show enough for us to tell. It is very hard to get a useful photo of the inside of a fount. Light surface rust shouldn't be a problem. Deep flaking rust with large pieces coming loose is a different matter.
