I need to cut out a section of 4" CI pipe to replace a cracked 4 x 2 CI san tee. The pipe is tight to back of the wall so I don't think I will be able to get ratchet chain snaps behind the pipe. What is my best option to make two very tight cuts? Sawsall with CI blades? or Grinder with cutoff wheel? thanks.



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Either one will work fine but the grinder will be quicker.

plan on drywall/plaster repair. i used a lennox sawzall blade the other day to make one cut in THICK cast iron pipe. i don't remember the number but the blade was curved like an arabian sword. i cut slowly and squirted some oil as i went along.
i know we aren't supposed to use them but i find in that situation the all rubber fernco to be the easiest to use. you aren't worried about needing strength for a horizontal pipe to prevent it from sagging. it is a vertical pipe and it is not going anywhere.

I have made 6 cuts thru 4" cast with one of these blades and it is still cutting like a hot knife thru butter [www.diablotools.com]

I need to re-evaluate this repair. there's a chance I didn't install the cast iron hub donut correctly.
Really tight spot to try to get hub saving donut and 2" ABS repair pipe in. Talked to another plumber today and he reminded me about cutting the CI stack. Don't want the whole thing crashing down. Returning to apartment again tomorrow to see if it's really a cracked san tee or a plumber who is having difficulty with repair donut (what's the correct term for that?) are there different brands that are better quality and easier to install? tomorrow I will try to make sure hub is totally clean and smooth. thanks for replies. I have a short video of the current leak. Can you upload video to Plbg.com?



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you cannot host images and videos in plbg,com. But you can upload videos to many free sites. For example you can upload your video to youtube and then post a link here.

I have yet to seat one of those donuts, to my liking. What I was considering doing the next time, is to drill tiny holes, straight down into the donut, to relieve some of the compression as it goes in.

Being a DIYer I have only dealt with donuts three times and I had a hard time even removing them. One time I had to stick a 2x3 down the shaft of a 4" CI fitting connected to another CI fitting below with a donut. I rocked that 2X3 back and forth trying to unseat the donut and it wouldn't give in and eventually I cracked the CI fitting instead.

they sent the lead plumber out and he cut the 4" stack twice and removed the san tee causing the problem. when it was initially installed many years ago the 2" branch was back graded. I was successful using a hub saving donut years ago as an apprentice but I had reasonable access unlike this one. It's OK to get beat on occasion to keep you from getting a swelled head. Nice to have back up. Most likely I damaged the hub trying to get the old lead, oakum and 2" galv. pipe out. Need to be more careful next time. Thanks for the responses.



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