In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
I have a100+ year old steam boiler that I am working on. There is a 4" nipple in the bottom of the boiler that is rotted out. I know when I crank on it with my wrench it will crush an collapse, requiring me to chisle out the threads. The problem is getting my hands on a 4" pipe tap. They cost $600 or more on line. Crap! I need to chase these threads and will probably never use it again.
Any one have a trade secret on cleaning up these threads without a tap?