Hi, I wanted to try to clear a backed kitchen sink, so today I removed the P-trap and the slip fit PVC pipe and I discovered that my drain that goes to the outside of the house was severely clogged. After clearing the drain I found out that the aluminum pipe is severely rusted and is falling apart. So I know I need to replace the pipe but it's screwed into a brass fitting. And the pipe is corroded. So do you have any ideas I can use to remove the aluminum pipe without damaging the Brass fitting?

Thanks

Pass7100

That aluminum pipe isn't aluminum, it's galvanized iron. Spray the threads with WDE-40 and put a pipe wrench on it and turn it out counter clockwise.
Once the old pip's removed consider converting to PVC with a threaded male adapter, use Teflon Tape on the threads. (see image). You may now run PVC to the sink. Don't forget to prime the fittings before gluing. Hope this helps and thank you for rating my answer. Tom PS> if you have trouble removing the old pipe click on back and tell me about it. T.