Washing machine drain pan

I'm putting this in the plumbing section rather than the large appliance section, because it really has nothing to do with my washing machine, I hope that's ok.

I needed to replace my washing machine drain pan, as the old one had gotten cracked pretty badly. Anyway, the drain that was connected to it was a metal threaded drain that basically just screwed down onto the pipe, kind of securing the drain pan to the floor. I can see there was some sort of silicone gasket or caulking of some sort underneath it at some point, but that had deteriorated for the most part.

So the drain is in good condition, and easily reusable, plus I don't think I can find another one like it anywhere, so I measured and cut the proper size hole in my new drain pan to place it and screw the drain on. And it works just fine. However, I'm a little worried about not having a good seal under the lip of the drain, so some water can get underneath it and drain down outside of the pipe. I can't seem to find a rubber gasket or washer with a 2 inch inner diameter that this drain has. I found a rubber washer that had a big enough outer diameter, and for now I have cut out the inside of it, making it kind of fit. But it is a bit thick, and I'm not really liking the seal it made.

Does anyone know the proper way to seal the lip of this drain? I imagine caulk would just break loose as soon as the washing machine was moved or replaced, because the drain pan will twist around a bit, so I don't want to use calk. I've only looked at the hardware store. Would a plumbing supply shop be more likely to have the right size washer?

I'll include some pictures below to try to clarify the situation. The rubber washer you see is the one that I have cut up to make fit. But it's a shy too small and doesn't fit on very well. Any advice would be appreciated. Thanks!

Here is the drain pan:


I backed the drain out a bit so you can see how it fits. But it doesn't fit very flush to the floor. I know it won't with a gasket, but this one just doesn't fit quite right, and is a bit too thick:


More images of the drain:


I took the washer off in this one so you could see the whole drain without it.

 

That looks to me like a bathtub drain. I've never seen a drain specifically for a drain pan, though they may exist.

I would probably treat this like a kitchen drain. Remove the rubber washer, and instead use plumbers putty around the underside of the chrome lip. Tighten it down so the putty seals well.

I would probably also secure the pan so it doesn't move around when you're installing the washer. Regardless of how you mount the drain, movement will likely weaken the seal. I'd probably silicone it to the floor, or maybe use a construction adhesive if you don't think it's going to be replaced any time soon.

 

Tub or sink drain, Plumbers putty. Usually drain sits up about 1/2 or more inch in pan. Have never seen a drain like yours,

 

That drain fitting is designed to be used in a pan where the drain hole area is recessed and also tapered to allow the strainer top to fit flush. That rubber washer is designed to be put under the pan. The top would normally get sealed with plumbers putty. In your case I might consider using silicone.

It actually installs just like in a bathtub.

 

Thanks for the replies. The washing machine came and got installed before I got your replies. I think the way I have it now will work, however, I think I'm going to redo it anyway. I put the new pan in the same location as the old one, as the washing machine is the same size as our old one, however the hoses are in a different location, and they are butting right up against the wall and at a sharp bend, putting strain on the hose and probably the connector on the washer. So I'm going to get a new pan, and redo it anyway. Need to put the pan away from the wall a couple more inches to give room for the hoses.

Thanks for the advice.