My house is 40 years old and all the plumbing in it is original. I recently discovered a constant leak in a bathroom that had been out of use for well over a year. I've only owned the house for 18 months but it was clear once I moved in that no maintenance had ever been done on anything in the house. I closed off 3 rooms including the bathroom to save on HVAC costs and until I was ready to put them right.
The leak was coming thru the single lever mixing valve and going to the tub spout. The tub spout was not tight against the wall and when I unscrewed it saw that a plastic threaded insert in the spout had broken and that some metal threads were missing on the nipple. Closer inspection of the nipple showed that there was significant corrosion on the out side and the inside as well. It seemed obvious to me that replacement was needed.
I enlarged the hole for the nipple so I could see where the nipple screwed into the the feed pipe fitting. At this point I applied penetrant to eat the rust and hopefully make removal easy. I banged on the nipple in all directions hoping to create a crack in the rusted threads so penetrant could get in and do its work. This process went on for 3 hours before I started to try to turn it with a pipe wrench. 2 more hours went by with alternately sparaying penetrant, banging the nipple and applying torque with the pipe wrench all to no avail.
The pipe started to deform where the pipe wrench was gripping it (only a half inch sticking out from the tub liner) and quite soon after it was obvious just how corroded the nipple had become as the metal gave way.
I purchased a new nipple and an easy out sized for the stubborn nipple (1/2"). Sawed off the end of the nipple that had given way and proceeded with more penetrant and banging the easy out in the sawed off nipple. Another 2 hours later (7 hours all together), I decided to write this post and ask if anyone here had faced a similar problem and if so, how they solved it.
When I considered possibly using heat I realized that heating the nipple would only expand it and that to heat the fitting it was screwed into would require removing the drywall behind the plumbing to be able to heat that fitting. I also considered trying to freeze the nipple but don't have anything that can do that like liquid nitrogen.
I figured that 7 hours was more than enough time for the penetrant to work and to be able to back the nipple out with the easy out. I obviously don't want to destroy the fitting the nipple is threaded into or the line feeding it, but I just might have to open the wall up from behind and cut the fitting off and put in new.
Should I give the penetrant over night to work or just plan on cutting the dry wall out and replacing the fitting that the nipple is threaded into?