Cast Stack need to tie into?

Old 04-06-21, 03:16 PM
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Cast Stack need to tie into?

I am putting in a under mount sink with new counter tops.
Since the sink will sit lower than the orig. I need to lower the drain.
The drain that is cast as well.
What do I do for taking out this old drain and putting one in lower?
I know I will need to support the stack above where I am working.
What do I use to cut the cast?
Will a metal blade on a reciprocating saw work?

Old 04-06-21, 09:29 PM
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I'd use a grinder, but there are sawzall blades made for cast.
Old 04-07-21, 06:03 AM
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I normally use a fine tooth metal cutting blade in a reciprocating saw. Get several because once the blade dulls cutting get's really slow. A cutoff wheel or grinder also works but throws sparks which can be a fire hazard and makes smoke (ever smell burned poo juice?) so it's more of a mess inside a home.

Also, make sure you support the weight of the cast iron & steel pipe above so it doesn't drop when you cut out a section.
Old 04-07-21, 06:16 AM
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I would definitely use a grinder and 1/16" cutoff wheel for as much of the cut as possible. Leaving less to sawzall. A standard fine toothed sawzall blade will burn up almost immediately, but the ones with medium sized teeth (for thicker metal) last longer, especially if you cut slowly and lubricate the cut with oil. As mentioned,, there are also blades specifically for cast, such as the Milwaukee Torch (carbide) or better yet, the Milwaukee Torch (with nitrous carbide). But they are quite expensive compared to ordinary blades.

When buying sawzall blades, you get what you pay for. Milwaukee Torch brand is one of the best.
Old 04-10-21, 06:32 PM
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couldn't find reciprocating blade with diamond grit.

Used cutoff wheels on angle grinder with diamond.

That worked like cutting through butter on the cast.

On the galvanized pipe not so well, ended up using regular cutoff wheel for metal.

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