House was built in 1958, the pipe is in good shape except for the small rusting now leaking nail size spot. I tried rustoleum, that is not helping. will epoxy work?
Epoxy is unlikely to make a lasting repair. What you need is a pipe repair clamp, which is a stainless steel band with a rubber gasket inside it - the "in place repair" type have a beveled overlapping edge so the clamp can be opened up and slipped onto the pipe, then clamped in place to seal the leak. They look similar to the "hubless coupling" clamps but those typically use a gasket that needs to have the pipe cut to slip onto it.
I assume your leak is something along the lines of the following:
Even though the hole may look small on the outside, it is like a tooth cavity, the corrosion on the inside is much larger. In most cases, even a small leak is an indication that the entire pipe needs to be replaced.