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I was replacing the sink this afternoon when I noticed that the p-trap would not reach the drain pipe. No biggie, right? I'll just buy some extensions from the local big box and be on my way.

I attempt to take off the drain pipe so I can fit an extension on and what I can see appears to be someone who took a 1.25" pipe, shoved it into the 1.5" hole (with the threads "holding it in") and then tightening everything up.

Now, I'm trying to unscrew this mess (literally) and I can't get the pipe out of the 1.5" drain. I'm wondering if I should try to heat up the system with an acetylene torch to try to make everything a bit more pliable or if I've got no other choice than to get a plumber to come and rerun the drain in the back of the wall.

The input of this community would be most appreciated.

Here are some photos:

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Once again proving that everyone who lived in your house before you was crazy. I just hope to not be the next owner's crazy guy. –  Eric Lippert Apr 28 at 16:06
    
Just wondering: why do none of the answers suggest a little LiquidWrench or similar rust-reducers/lubricants? You almost always have the best results when combining chemical and mechancical(big wrench or chisel :-) ) attacks. –  Carl Witthoft Apr 28 at 16:58
    
I wonder if it's soldered. –  Some Free Mason Apr 28 at 18:59
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I had to eventually call a plumber -- it just wasn't coming free the way I would expect. He wailed on it for almost 20 minutes -- sawzall, chisel+hammer, the whole nine yards. When he pulled it out it was not soldered, but just calcified so entirely that it bonded extremely tightly. –  Peter Grace Apr 30 at 19:55
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8 Answers 8

up vote 5 down vote accepted

I'd slip a cheater bar into the drain and see if you can pop it loose by turning it clockwise (so you don't unscrew the tail-piece). If you can get it to turn without twisting it you should be able to get it to pull out. If you can't and it starts to twist the pipe without breaking it loose, cut it off with a hacksaw close to the tail-piece leaving enough of outside to grab with a pair of vise-grips. Then take a hacksaw blade and carefully cut through the pipe from the inside. You should then be able to use a vise-grip or pliers roll it in to a smaller diameter and pull out the last bit.

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This is essentially what the plumber did. I didn't have the stomach to try to sawzall it myself. –  Peter Grace Apr 30 at 19:56
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Do not use an acetylene torch! That will melt the pipe and make holes, cracks, etc. in it.

I suggest turning with great force. A 18+ inch pipe wrench applied to the insert will probably unscrew it so it will just slide out.

Otherwise, it will turn the outer pipe loose from whatever it is connected to. If the outer pipe was built well, it is fastened to structural framing which will easily hold it in place. Just unscrew the whole assembly and either replace the 1.5 inch pipe or separate the two and replace the 1.5 inch.

If that is a standard wall, there is an elbow just a few inches inside the wall, so it will be quite easy to re-install.

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I'm not sure unscrewing the tail-piece and reinstalling is the best idea. Not only can you not inspect if for leaks without removing a chunk of the wall, if the threads are rusted together it may not unscrew cleanly inside the wall. Unfortunately there doesn't look like there's enough sticking out to get a pipe wrench on it to prevent it from turning without damaging the threads for the slip-joint. –  Comintern Apr 28 at 5:05
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Dissimilar metals, the inside of the iron pipe will have rusted so tight to the brass pipe that you will need a half-round cape chisel and patience to get it out.

This is a normal installation, the 1 1/4" pipe is supposed to slip in rather loosely into the larger pipe with a threaded ring and rubber gasket to make it water tight. Years of corrosion have won out.

Been there on this one; if the recommendations already made by wallyk and Comintern don't work, chiseling it out is all that's left.

It would help to know what's inside the wall as in, does the iron pipe thread into an iron Tee with the rest of the system being iron till it gets to the larger diameter pipe? Most of the Swede bar methods mentioned will need to take that into consideration otherwise dealing with the aftermath can be kind of annoying.

BTW, I have seen 1/2 iron pipe rust internally till the water channel was less than the diameter of a pencil, quite something to see.

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I have seen those older pipes too, bad stuff. Galvanized pipe will usually rust through at the threaded portions of fittings where the galvanizing has been removed. This is worth checking into on its own... –  Jack Apr 28 at 5:45
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@Martin James
Agreed. As the volumetric thermal expansion coefficient of brass is nearly twice that of steel at room temperature, but the amount of heat needed for sufficient effect might damage the existing installation (or you), chilling the pipes would probably be the better option.

I've freed jammed press brakes with a whole lot of ordinary ice, and the dissimilarity in metals there is pretty minor. But check with your local welding gas distributor--they may have dry ice. Just remember that it can burn you, too. And if you haven't worked with it before, you might be surprised how fast it can disappear, so be sure to be ready to use it as soon as you get it home.

Also, please heed Fiasco Labs' advice about the breaker bar.

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+1 I was going to comment about the coefficient of thermal expansion. Heating on and cooling the other would cause them to break free from each other. –  Some Free Mason Apr 28 at 13:47
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I know exactly what you need here:

enter image description here

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Here! Here! Yankee ingenuity!! –  Jack Apr 28 at 5:43
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That's a puny hammer. You're not doing it right, if you're not using a sledgehammer. –  Tester101 Apr 28 at 10:51
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You could try shrinking the inner pipe with cooler spray. That will temporarily provide a bit of clearance and crack scale/rust. If you can warm up the assembly first, even better but, if you use a gas-axe for that, just use a bit of gas AND NO OXYGEN. An ordinary butane blowlamp would be safer :)

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I would have used a hub puller.

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Can you explain what a "hub puller" is and how it would have helped in this situation. –  ChrisF Apr 30 at 21:25
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open the wall, remove the old pipes, install a thermostat.

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How will a thermostat help with the plumbing? –  Niall C. Apr 28 at 19:10
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