When you’re installing a new sink and need to put the drain tube into The bottom part of the porcelain sink, IT’S TRICKY!! If you’ve never done one of these there’s a few techniques but you need to understand. There needs to be plumbers potty in between the top metal flange and the porcelain. It is so easy to tighten disassembly up where the metal flange just barely touches the porcelain. When this happens you well ABSOLUTELY have a leak. I don’t care if you do this process 50 times. If you do not understand this concept it will leak every single time.
Pulling down on the drain tube and slowly forming the plumbers potty will get the momentum moving in the correct direction. The plumbers potty should come out very smoothly, Then you can just simply trim it with a knife and that’s it. The biggest problem is that people titan these assemblies up with a wrench. Plumbing is more finesse than Brute Force. Hope you found the video useful