Rusted Sink drain pipe

[erthwrks89]

Daughters bought a restaurant and Bar The main part of the bar is from 1948 it has a crawl space which has much to be desired. There is sink in the bar that has about 10' of 2" galvanized drain pipe and then a 90 and 8' more feet ,in the 8' section it is completely rust through then it goes into a 6" vertical black cast iron pipe. The question is can I run plastic pipe into the black iron drain pipe from the sink? Is there anything I can use to soak the galvanized pipe where it enters the black pipe? Iam really nervous about cracking or screwing up the black drain pipe .Thanks For your Time --erthwrks89

[Mike Swearingen]

No problem and no need to try to unscrew the old rusted iron pipe.
Just cut the old 2" drain pipe off a few inches above the connection to the 6" with a pipe cutter or reciprocating saw with a metal cutting blade, and use a Fernco coupling or a no-hub coupling to connect either ABS black plastic or PVC white plastic pipe all the way back to the sink. Don't forget the 1/4" of slope per linear foot from the sink toward the main where it turns "horizontal".
A Fernco is a neoprene rubber sleeve with two stainless steel clamps around it to seal onto the plastic and the old pipe. A no-hub has a stainless steel sleeve over neoprene and is stronger and more rigid. Available at almost all plumbing supplies (big boxes, hardware stores, etc.). Fernco and no-hub connections meet most local codes for drain pipe.
Good Luck!
Mike

[Cass]

Mike is right about replacing the pipe but don't use the type of Fernco (that is a brand name) that only has the 2 bands. That one is supposed to be used underground only (sorry Mike). You need a shielded or like Mike said no-hub Fernco coupling or any brand of shielded no-hub coupling with the band of smooth stainless steel .
They have some that look similar to what we have described but the band is corrugated not smooth. These are not what you want to use.

[erthwrks89]

Thanks Guys --I appreciate the help , with this project Iam sure Ill have more questions---- erthwrks89

[finnegan]

When you cut the galvanized pipe, try to knock out any scale or deposits on the remaining stub. Make sure to leave yourself the appropriate clean outs as well. good luck.