10-13-2008, 11:48 AM
Fishboy, In my experience that 3/4 worth of "gunk" is most like holding the old gal pipe together. I love showing this to my customers, sometimes you can't even see daylight thru a one foot piece, They want me to re-pipe the whole house. If there is a basement or crawl space below, you could try installing a cleanout tee ot wye. Chemicals may eat thru the gunk then finish off the pipe for dessert. I am a plumbing contractor working on hundred year old houses in Portland, Oregon.
Tom
Tom