Hi,
When I was assembling the table, I wanted a better way to fill and drain the water, as I won’t use my table too frequently and didn’t want the water sloshing around and evaporating. I saw a video where Casey Customs created a forming die and enlarged the drain.
Youtube Video with for Attribution of this idea 
I modified it a bit by making the hole bigger to accommodate a 1.25” NPT stainless bulkhead that I connected to a PVC drain with a motorized valve. I made a forming die that I used with my knockout hydraulic punch and accepts a 3/4” pilot bolt. I am done with this die, and it is just taking up space. If anyone wants it, happy to ship if you pay USPS standard small box shipping. I am clearly no machinist, but it did work Another good use of 304 stainless - ha.
I also turned down the flange on the bulkhead to make it round, thinner, and allowed me to add a topside silicone washer.
Here is a link to more pics of how it was used to form the table
