Downsizing Pressure Stubs
Normal threaded pipe caps are bulky and require a large hole. Try this tip to stay on the small side.
When drywalling and tiling bathrooms, I like to install temporary 1/2-in. or 3/8-in. pipe stubs in all threaded drop-ear elbows so the supply lines can be pressurized. But I find that the normal threaded pipe caps are bulky and require a large hole. To stay on the small side, I take a 4-in. black pipe nipple and weld one end closed. Then I grind it smooth. This way, I only need to make a hole a little larger than the pipe’s outside diameter. My tile guys particularly like this trick, as it can be difficult to make a hole large enough to clear a normal threaded pipe cap that will still be completely covered by the fixture escutcheon. As a note, I always use black pipe, as welding galvanized pipe will produce unhealthy fumes.
— Don Marty, Verona, Wis.
Edited and illustrated by Charles Miller
From Fine Homebuilding #269