I'm trying to remove the drain/flange from a kitchen sink so that I can install a garbage disposal unit. I can not get the wide nut on the underside of the sink to turn. I'm assuming it's glued or rusted or painted into place. Is there any sort of special tool to help remove it or anything I can do to try and loosen it up? Right now I'm just using a 12 inch groove joint plier to try and remove it. It's just barely big enough to get a grip on it.
Attached is a photo of the underside of the sink
Tap (don't overdo it and break the "ears") with a hammer and nail or hammer and punch against the projecting "ears" - and do as many of them as you can easily reach, rather than only tapping on the most accessible one (at least until the thing starts to move.)
Scribe a line before you start that goes across both parts so you can detect even a small movement. The shock of tapping may start to move things where grabbing with pliers won't budge it.
If no joy, add heat - use a serious heat gun if you have one, or a torch VERY carefully and pretty much so far out that the flame isn't directly contacting the sink parts, at least at first.
A Tub Drain Removal Wrench might help in this scenario. These can be found at your local home improvement or plumbing supply store.
You might be able to turn the drain instead of the bolt in order to remove it.
Another idea that may be necessary if the thing is so rusted and corroded is to cut the lower section of the basket assembly off. This can be done by several methods. The easiest one may be to cut into the side of the lower assembly along one side (vertically) with a Dremel tool with a cutoff wheel. It may be necessary to cut it on only one side or both. When cutting be careful not to grind up into the sink casting. After it is cut you can open up the cut with a chisel or pry bar. This will relieve the threads and allow you to peel off the lower basket assembly.
A sufficiently large strap wrench could be used. But at some point tool cost may approach the cost of fixture replacement.
When the nut is stuck that well, the basket has a tendency to start to slip before the nut. So instead of twisting the nut loose, you'll end up spinning the basket.
At this point it's likely you'll have to replace the basket anyway, so trying to save it could be a moot point. I'd start by trying to crack the nut. Use a hacksaw blade or oscillating tool, and cut as far through the nut as you can. Make two cuts, one on each side of the basket. Do your best not to damage the threads of the basket, but don't worry too much since the basket is easily replaced.
Once you have the two cuts, try to break the nut into two pieces. Use a flathead screwdriver or cold chisel, and poke, twist, and pry at the notches you cut.
NOTE: If this is a one piece sink, and that's not a seperate basket. Disregard the above.
