Anyone know sink drains well??

I've replaced them before without incident, (in other sinks). Here's the situation: I decided to replace the drains in my kitchen sink because they were looking pretty rough with paint chipping off, etc. The new ones both leak like crazy. Water is getting under the flange and past the plumbers putty, and past the rubber gasket that is on the underside of the sink, where the big lock nut is. Upon close examination of the new drains, I can see where the water is getting under the new drain flange edge on the top side of the sink....there is a slight gap in a couple locations. Could the sink be goofed up?? I know realize that these gaps were slightly noticeable before I pulled the old drains out, as my wife has noticed bubbles come from these very same area, and she also noticed the water level drop if water was left in the sink for a long time. I assumed that this was water creeping past the drain itself, as we never noticed any leaks or water under the sink. Now, the old drains had the "cup" under the sink that was pushed up against the bottom side of the sink by a nut that was on the same lower part of the drain that the tailpiece nut screw is on. The "cup" has some rust in it, which probably indicates water was getting past the seal on the old drains and sitting in it. The new drains are just like you might picture them: Drain gets placed in from top of sink, I rolled plumbers putty to Number 2 pencil size around hole in sink before placing drain in hole. Rubber gasket on bottom side under sink then friction washer, then big nut. (Old drain description is: drain in from top of sink over plumbers putty, thin rubber gasket on bottom side of sink, then "cup", then nut that pushes "cup" up while pulling drain down to sandwhich sink bottom).

Don't know if this has anything to do with anything, but the new drain has a big thick rubber gasket that goes against the under side of the sink. The old drain has a very thin gasket that is between the underside of sink and "cup".

I've attempted to lessen and add plumbers putty, thinking it wasn't the right amount, but still leaks the same amount of water. I thought of using the "cup" again, but it doesn't allow the lower part of the drain to come through enough to get a jam nut started on it.

I figure the sink needs more leak prevention where the tiny gaps are not sealing, and wonder if I could use silicone caulk instead of plumbers putty?? Or should I use a thinner rubber gasket against the bottom side of the sink? OR is it as simple as the "cup" things are essential to remain with the sink and I have to get the exact drain replacement? Again, there is no difference in the new drain other than the lower part, (with the smaller of the two big jam nuts), being a little longer the through the cup to recieve a jam nut. The new drain is the same depth as the old drain, and I matched the new one as closely as I could even visiting several stores. I have not seen that I can purchase a drain with the same long length to this bottom part of drain.

Would sure appreciate any thoughts!!

Visser

 

There should be enough plumber's putty to squeeze out all the way around. Silicone caulk won't necessarily be any better because it lacks the firmness of the putty to fill the gaps when the drain is tightened. Besides, it the silicone doesn't work, it is the dickens to remove.

It may be that the design of the sink requires the 'cup' in order for there to be pressure in the right place to seal properly.

 

Chris, I was sort of expecting someone to suggest that the sink design might require the 'cup' underneath. I think you're right, and my only solution is to replace the drains with the manyfacturers exact replacements. I'll do some searching.

Makes sense to use the plumbers putty vs silicone!

Thanks,

Visser