Disposer flange and sink basket in cast iron sink

Ok, here is a newbie question for you, be gentle !

Am installing a Kohler cast iron sink, replacing an old stainless sink. Currently, I have an In-sink-erator garbage disposal on one side, regular sink basket drain on the other bowl. I want to keep this same arrangement on the new Kohler sink, but my question is:

The hole(s) in the bottom of the cast iron sink have a large, curved radius lead-in to the hole. I am just now noticing that the other sainless sinks I am looking at have a rather flat area where the flange seems to mate up with nicely. However, I am noticing that the disposal flange and the Kohler sink basket flange both have quite a right angle underneath the flange, very small radius. This really seems a little strange when I set these in the hole. Am I supposed to be using a special flange for the disposal and basket mounting?

I have looked high and low for a special flange, no one seems to make one. I can only assume that this means that all the parts out there must work.

So, I guess load up the underside of the flange with plenty of silicone before installing and completely remove the excess after tightening the nut underneath?



This one is on a stainless sink. The cast sink will leave less space to snap in the ring.

Actually the only thing you have wrong is loading the flange up with Silicone RTV. Your Kohler cast iron sink is a good one and will probably outlast several disposers. You may want the option of removing the flange and using a nice new shiny one off one of your new disposers at sometime. Despite what the Silicone RTV users claim it does have very strong adhesive properties making removal a bear of a job.

The cast iron sink is much thicker than a stainless sink and the flange will fit. However, if you are using the Insinkerator style flange with the snap ring I would recommend a second person to push down from the top while securing the ring. It can be a lot of fun to do alone there is very little room left.

Ise

It can be a lot of fun to do alone there is very little room left.

That is why I have an ISE snap ring installing tool. It is helpful with stainless steel sinks, but INVALUABLE with cast iron ones.

That is why I have it too!
Joe Homeowner DIYer however probably will not have it...

ring

And by the time he does get it installed, even with a helper, he is going to curse the day his "decision maker" decided she wanted a disposer.

Sooo, plumbers putty instead of silicone? I think the instructions with the basket says plumbers putty, but I thought it tended to dry out and crack?

hj said:

That is why I have an ISE snap ring installing tool.

Click to expand...

What? A tool I don't have? I've installed and un-installed ISE disposers on SS, CI, and manufactured stone sinks, and never felt the need for another tool. What am I doing wrong? Or right?