I have a two bowl vanity with PVC drain lines. One sink drains fine, the second very slow. I removed the S/S trap on the slow sink and found it to be 80% clogged with a hard white substance. Not sure what it is. I suspect maybe dried toothpaste? But that was only a guess for lack of a better guess. I took it to the garage and put in in a vice and spent a half hour scrapping it clean. But when I looked further into the PVC where it goes through the back of the vanity and into the wall it is equally clogged. I could not easily clean it out. I reassembled the trap, but it is draining just as slow. Any suggestions? I am thinking I may have to remove the vanity and the drywall, and replace the clogged section of pipe, but that seems drastic.

I have a two bowl vanity with PVC drain lines. One sink drains fine, the second very slow. I removed the S/S trap on the slow sink and found it to be 80% clogged with a hard white substance. Not sure what it is. I suspect maybe dried toothpaste? But that was only a guess for lack of a better guess. I took it to the garage and put in in a vice and spent a half hour scrapping it clean. But when I looked further into the PVC where it goes thru the back of the vanity and into the wall it is equally clogged. I could not easily clean it out. I reassembled the trap, but it is draining just as slow. Any suggestions? I am thinking I may have to remove the vanity and the drywall, and replace the clogged section of pipe, but that seems drastic.

Did you send a snake up in the wall?(see image) Remove the "J" bend from the trap and send a hand snake.(see image)into the wall. You;llruninto a 90 about 8" in but once past that you only have 6 more feet to put out. Flush with hot water. Good nuck and thank you for ratinhg my answer. Tom

Thanks for the suggestion. I did try a manual snake, did no god. I didn't know they made one like you showed, I will look for one.