Old plumbing trick: stuff dripping pipes with bread to keep solder dry

Originally published at: https://boingboing.net/2019/05/29/old-plumbing-trick-stuff-drip.html


Ah Reddit; it’s like the flea market of the internet, whose customers and sellers are nothing less than the finest crazies.


Roger That!


I wish they’d have shown it in action. I’m confused as to how you get the bread into the leaking pipe. I had a leak in a sealed pipe once and didn’t want to shut the water off to the house to fix it. I’m assuming this trick is not for fixing that situation…as I clearly can’t stick bread into a sealed pipe. But, if the pipe is not sealed…then…won’t water pour out of it?


I think this is for a more minor leak. I’ve pulled chunks of bread and stuffed them into both sides of a pipe that I’m patching to solder them. Even a small amount of water left in the pipes can heat up, turn to steam, and blow your solder joint out. The bread stops that. Use basic white bread - don’t want fancy seeds getting stuck in your faucets :wink: .


Screw solder. I’ve almost burned down my house too many times trying to solder in tight spaces.

Shark Bite and Pex all the way!!



Okaaay, how does the bread get out of the pipe afterward?


It’s standard procedure to flush out new supply pipes before connecting fixtures, or at the very least remove aerators/flow restrictors from fixtures before applying water pressure. Mainly to remove flux and solder residue. I have to think that bread is going to disintegrate almost instantaneously under full house pressure.

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Yep, the most sure-fire way to eliminate a drip is to crack open the pipe “upstream” from where you’re trying to solder and letting it drip at that location instead. Then throw in a shark-bite coupler (or better yet a shark-bite shutoff) and Bob’s your uncle.

I think this is used when you have shut off the mains, and drained down the pipes you are working on, but there are still horizontal sections of pipe with puddles of water in the bottom, and maybe all kinds of bubbles and airlocks further up the system which may dribble more water while you are working on the job, and mess up your solder joint.

If you stuff some bread into the pipe, it soaks up any drops inside of the pipe, and can stop small amounts of water drooling down from the rest of the system. It’s not there to resist mains pressure or anytime like that. The bread gets sealed in when you make the joint. When you turn the water back on, the bread will turn to mush and get flushed out.

It is probably a bad idea if you are plumbing in a shower, though you could probably take the head off. Anything else ought to be fine. I did most of the plumbing in my house, but I did not feel the need for this. He seems like a nice guy, though.


Pex is great stuff. I had to redo the plumbing in my 2nd floor bathroom and used Pex. Navigating Pex pipes from the basement to the 2nd floor between walls was easy due to its ability to bend. It would have been a nightmare trying to do that with copper.

The trick he explained works if you have a horizontal copper pipe that’s opened up while the water is off. As you try to solder it water gets drawn to the heat and you’ll never get the pipe hot enough to get a good bond. The white part of Wonder Bread or something like it works well because it’s almost all starch that will dissolve in the water afterwards. They sell manufactured plumber’s bread, but it’s basically the same thing. As someone already noted, you’re supposed to bleed your lines before you put your fixtures in so that you don’t get any debris stuck in your aerator screens.

Another situation is if the valve is old and won’t completely seal, it only takes a tiny bit of water to turn to steam and blow the solder out of the joint. This technique was more useful before the advent of the SharkBite style of fitting, as others have noted.

There is a tool for this that works much better than bread as it will stop a significant amount of water as you are replacing a valve:

Sigh. As everyone knows, that’s what the gorilla is for.

Correct, not for that situation. I don’t think it’s even possible to soldier pipes that are still filled with pressurized water because the water would act as a heat sink and prevent the pipe from getting hot enough to accept the soldier.

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