Keeping water out when sweating copper

I just found a product called "Plumber's Bread" at Lowe's last weekend and tried it today. It's white, kind of styrofoam-ish stuff you push into a pipe before sweating a joint to keep water out. It then dissolves.

Seemed to work very well, and no clogged aerators.

For what it's worth, while I had the water off and pipes drained, I sweated a full port ball valve into both the hot and cold 3/4 pipes leading from the basement to the 2 floors above, figuring that for future repairs in the basement (e.g., water heaters, water softener), I could isolate the upper 2 stories' worth of pipes and not have to contend with water coming from above.

Thanks for the report. Sounds like it could be useful stuff to have around.

I like Wonder Bread. Enough to plug up your whole house on sale for 99cents and snack if you get hungry. For the price, I'll clean out the aerators.

Good points.

On the other hand, might be nice to have something you can throw into your tool box which won't harden up or get moldy, and is always ready to work.