As the title implies, I want to know the consequence of a short cut fix for this frame. I know the proper repair would be to replace the seat tube. But given that I still ride this bike (now with a much longer seat post) as-is, how improper would it be to just have the crack filled in with brazing material? Would that sort of repair be strictly cosmetic?
For some back-ground... I bought this 531-tubed frame (unpainted) from an amateur frame-builder in the 1970s. At the time I (temporarily) had a very short seat post in it, which ended right where the crack is. While the bike was stationary something heavy fell on the seat resulting in this crack -- apparently levered out by the seat post. I replaced the post with a very long one and continued to ride it and have not noticed the crack getting any worse (although it might be).
Recently I have dusted off this old friend and started to ride it. Now I am trying to decide what to do with it first if I want to get it repainted.