How do you remove an old 4" cast iron plug from a trap (Y fitting)?

Question

I heard a story from a guy who tried and tried to get this plug out, at the trap. It had a square block as usual on the top for putting a pipe wrench. He called a plumber. When the plumber came, the homeowner left the room for no more than a minute and the guy had it off, with no noise or banging. When asked how he did it, he said "trade secret". Anybody know? I have to get my plug off too.

Answer 1

You heat it with a torch.

Answer 2

Apply a torch to the outside rim of the pipe. The outside will expand from the heat, making the plug loose in the threaded hole. Any propane torch will work, just go around the outside rim with the flame for a minute or so is all it takes.

The best thing to do is to bust the cast iron out and replace it with a piece of Black Plastic ABS. Just cut the ends of the cast iron pipe evenly across, and drop the ABS fitting in place. There are rubber bands that go around the ends of the ABS / Iron pipe and is tightened with 2 large stainless steel clamps like you use on a car radiator. You will never have a stuck clean out plug again.

Answer 3

If the plumber did not use heat, he may have simply realized that the guy was turning the plug the wrong direction. When a threaded fitting is upside down (as being in the bottom of the trap) it can confuse your direction of turning correctly. Seen this done many times.

Answer 4

If you have caution about using heat, try ice pack, or dry-ice packed around it, the different contraction will loosen it's grip as well. I have used this method to free stuck gas valves.

Answer 5

It is an ordinary nut. Just use a little penetrating oil. Isn't that simple.

Answer 6

soak with winter green oil over night before you try to remove is best break free you can find and smells good also

Answer 7

i don't know where ranger c got his info, perhaps he is a plumber, but he is absolutely right on. good answer from this person.