I've got a number of pinhole leaks in a section of cast iron drain piping I need to repair. (I know eventually I'll need to replace the sections–Im looking for a temporary fix that will last a year or so until we've saved enough to have it done right.) The pinholes are covered with scales, but on the advice of a friend I scraped and wire-brushed them off. He said then to kneed the epoxy into a ball then work it into the hole. However, now that I have the scales off i see no hole (I guess because on the outside its a pinhole). Should I press the putty into the area where tge he was or attempt to drill it out with a small-diameter bit first?
This is a question simar to How can i repair a nail head size leak on a vertical cast iron sewer pipe in my basement but I'm asking a more specific question.
Best Answer
If it were me, I would be wrapping the pipe with fiberglass, not just sticking goop on it, in which case drilling the holes out bigger would be kind of pointless.
You could use something like this.
If there are pinholes in that pipe, there is more widespread rot in the inside (aka rust), just like Daniel Griscom is saying, and the pipe could be one unfortunate minor event away from decorating it's surroundings.
I would be evaluating how to replace that pipe with ABS or PVC, as well.