hammer on a threaded cast iron cap?

Hello-

During an unfortunate experience with a plumbing contractor, I was told that it was ok to hammer on a threaded cast iron cap (they were replacing a broken cleanout cap on a 4" cast iron pipe after jetting the line, and this was the method they used). My reaction to this was disbelief, as this seems totally bogus. I need to know for sure before I settle with the company - is this true??
A professional response is appreciated.
-sjj

If you meant to hammer on a threaded cap meaning like drive it in straight (like a nail) then no that's not ok.

If you meant to hammer on a threaded cap using the hammer to apply torque to the cap in order to turn it, then that's probably ok. Many people do this to remove caps. Generally if it's not going anywhere then it is cut out (being careful to not damage the female threads) before it breaks the pipe.

What happened? What'd they break?

Was it a cap or a plug? Was it cast iron or brass? Yes, it's OK to hammer on it. Sometimes that will break it loose, sometimes it won't. Using a chisel with a hammer is good and often works. Last resort (with thin brass caps) is to simply cut them out with a chisel and hammer.

Lakee and Herk:

It is a threaded, cast iron cap. They hammered it to put it back on, not to get it off! They couldn't unscrew the old cap so they broke it to get it off (fine). After clearing the clog, they then placed a new threaded cap on the cleanout opening, and proceeded to hammer it down to secure it (no wrench was involved). Bizarre.
Thanks for the input.

sjj22 said:

Lakee and Herk:

It is a threaded, cast iron cap. They hammered it to put it back on, not to get it off! They couldn't unscrew the old cap so they broke it to get it off (fine). After clearing the clog, they then placed a new threaded cap on the cleanout opening, and proceeded to hammer it down to secure it (no wrench was involved). Bizarre.
Thanks for the input.

Click to expand...

I'm betting it is a lead fit all. Lots of drain cleaners use them and will hammer them on.

The fit all is actually cast iron with about a quarter inch of lead around the sides/bottom of it, the top doesn't have that. So looking at it once installed you're going to see a cast iron plug with a lead ring around it. It also has rings on the sides which can look like threads from a couple feet away.
If that's what you have, then yes it gets hammered in. It's hard to find a new brass cap for an old cleanout as sizes and threads have changed and your threads may be damaged. Even if they do install a new one it's probably just going seize up and have to be cut out next time you need the drain cleaned.

There's another thread going with the lead fit-all. I have never seen one and although it sounds interesting, I'm not sure it's something I'd want to use.

However, if I understand the usage correctly, hammering it is completely normal.

Herk said:

There's another thread going with the lead fit-all. I have never seen one and although it sounds interesting, I'm not sure it's something I'd want to use.

Click to expand...

I've only seen them used on house traps but I suppose they could be used on clean outs elsewhere. I've seen them hold pressure where the waste was coming out of the trap vent (so the whole first floor worth of water) plenty of times. I've yet to see one pop off.

If the lead fit all is installed right it will hold back alot of pressure. I have seen one hold back a house filled to the first floor bath tub. The tub was about half full.

I still don't like them. If you don't get it on right it will not hold anything back. I have seen a few that when tapped it pops off real easy. That is not what you want when the line is full.