ABS thread to cast iron

[Yersmay]

I am now installing the shower drain... I have a cast iron drain with a threaded connection for the 2" drain pipe. I bought a threaded male ABS adapter, screwed it in the cast iron drain... It seemed like the threads were kind of sloppy against one another... and there is no tapered thread for things to mush up against each other. I put Gasoila on the threads, gently but firmly snugged the ABS fitting up into the cast iron... But before I bury this under a ton of mud and tile -- can I expect this ABS to Cast Iron threaded connection to be water tight? Or have I mixed materials that are not truly sized for one another? Thanks again for your advice.

 

[hj]

joint

First, check the Gasoila can to see if it can be used with ABS plastic. If not, then it will melt the threads and it will not make any difference whether the threads were compatible or not. The two threads are standard pipe threads, although the male adapter could screw all the way in without "tightening" since it is plastic and can compress to a certain extent.

 

[Sponsor]

 

[Yersmay]

Thank you HJ. Actually I called Gasoila and they said it's okay to use on ABS but not on PVC. I'm nervous about this threaded joint. Before it's installed, do you think I should take it apart and add some wraps of teflon tape, more Gasoila? Or will I make things worse?

 

[Cass]

While it is not customary dope the male threads and the female threads and screw it together. This should take care of any leaks. Be sure the threads are dry when applying the dope. Don't scimp on the dope.