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Plastic J trap on galvanized stub-out ??

1.7K views 5 replies 3 participants last post by  Dan1973  
#1 ·
Greetings;
am trying to replace the drain system under my new kitchen sink. Old galvanized basically fell apart when I tried to take out the cast iron sink (50's house), so I had to rebuild the drain system (and the new sink drains would not have aligned with the old piping anyway). The only original part remaining is the stub-out which uses a J trap (galvanized has downward threaded elbow). So - seemingly basic Q: can I use a plastic (cheap plastic) j trap on old galvanized threads?? all 1 1/2" plumbing. The problem I'm having is a very very slight leak at the junction of the plastic/galvanized threads. I have teflon tape on the threads and plastic nut is fairly tight, but still leaking. So I can't finish the install yet! Will a little putty be needed/advisable?

The guy at Ace hardware originally said I needed the brass J trap; he didn't mention that there was a plastic J trap - so when I found it the next day - I decided to save myself $20+ and bought the plastic to go along with all the other cheap plastic parts I bought.

thanks
Kelly
 
#3 ·
thanks @jmon - my understanding is that this adapter is for straight pipe; I have a male 90 elbow on the galvanized with threads; and I'm not using 'real' pvc (Ace told me they don't make fittings in PVC to connect with my galvanized threads), but am using those cheap plastic pieces with slip-nuts and washers. see pic
Image


also - forgot to mention, that the J trap didn't really fit the galvanized pipe anyway - the instructions indicated that no washer was needed, but the trap would slip around regardless of how tight the slip nut was on the pipe. So I added a washer which tightened the trap piece so it didn't move, but still leaks - probably cuz the washer ain't supposed to be there.