This is a simple question, but being a residential guy, I haven't done one before.

How do you guys seal the mop sink drain to the pipe? I wasn't sure what the "normal" way to do it was since it didn't have a gasket like a no-caulk shower strainer (which I was assuming it was going to). I ended up using JB Weld around it and made a little slope down into the drain.

Is this mop sink off the ground with exposed cast iron drain line or an inground/floor mounted mop sink with curbs?

Best Wishes

If it is one with a molded drain outlet, then someone stole the gasket which came with it.

It sits on the floor. You attach the drain to the base, but the drain is just basically a no caulk shower strainer with no threads and no gasket? The 3" goes through it, but there is nothing to seal it with?

Is it terrazzo? Fiberglass or China? A Fiat?

Best Wishes

As hj stated, it was probably furnished with a gasket.

I think it was a Swan. Even if it had a gasket, there were no threads and there
would have been no way to compress it in there

They do NOT use threads. IT is a press fit between the pipe and the hub. You lube the gasket and drive it in with a calking iron or blunt chisel.

...or wood dowel.

That would work, but you usually want something wider.