Getting waste disposal to seal to stainless steel sink.

[DerekG]

We replaced our old waste disposal about 1 year ago. The circular hole in the bottom of the sink is slightly dished but the fitting on the waste disposal is flat.

A water tight seal depends on a flat rubber annulus which is about 1mm thick x 1 cm x 10 cm dia. overall. This worked OK for about a year but now this is being extruded where the dished sink has to mate with the flat disposer neck fitting and it all leaks big time. I presume the rubber ring has stretched and is now oversize and baggy like the neck on an old sweater.

Suggestions are invited for the most effective bodge. Presumably lose the rubber ring then fill the ensuing gap with Boss White, Silicone Sealant, - or summat else ?

DererkG

[Ian Jackson]

In message , DerekG writes

Over time, any rubbery seal like this tends to squeeze outwards. One way of preventing it is to contain the rubber within a 'wall' of hard material, around the circumference. Obviously, the 'height' of the wall needs to be somewhat less than the rubber. When things get tightened down to the height of the 'wall', the rubber provides the seal, and cannot gradually escape. [If you see what I mean!]

[Jim K]

"plumbers gold"

Jim K