Vessel Sink Pop-up

I have a property with vessel sink that I'm in the process of remounting because the sink can swivel.

First I noticed it was missing the special fat washer that goes between the sink bottom and the counter top. So I figured I'd start with getting that when I remount.

But I have some other concerns also.

First is that the pop-up I took out has the over flow holes. Can I re-use that? Or will it create a leak below? (Given it's a vessel sink without an over flow feature)

The small counter top is actually some kind of finished plywood. Should I be concerned about being able to properly tighten the pop-up nut from below against plywood? Or how can I accommodate for this?

Thank you for insight and suggestions!

 

I have never seen a gasket between a sink and counter. Usually a sealant is applied at installation.

"...the pop-up I took out has the over flow holes. Can I re-use that?"
If it was working before why wouldn't it work in the future? Are you changing something that would cause it to not work?

"...Should I be concerned about being able to properly tighten the pop-up nut from below against plywood?"
No, the drain attachment has nothing to do with how the sink is mounted. Two totally different tasks done by different hardware. The sink is usually held in place with special clips or toggles underneath or just held in place by the caulk/sealant under the rim on top. First mount the sink. Then you adjust the plumbing underneath to mate with the bottom of the sink. The drain piping has nothing to do with holding the sink in place.

 

Thanks for the reply PD. However I'm thinking we're not on the same page in terms of a vessel sink?
I will send pictures.

 

OK, some pics....vessel sink. One shows a typical gasket that goes between the sink and counter. This sink that is swiveling was missing it, so I installed one. It still swivels a little. I'm thinking at this point to omit the rubber gasket that goes between the pop-up nut and counter....since the successful installation, pictured doesn't have it. But again, I'm leery about tightening that nut against plywood a plywood counter.



Gasket/mounting ring for vessel sink


Under counter attachment without the usual pop up gasket.


This is the problematic plywood counter and blue swiveling vessel sink below.

 

PD...Are you on with me? I'm still interested in your take on this?