Vessel sink with overflow

[bimfi122]

I decided to replace a vessel sink that sits on top of a granite counter in my dining room butler pantry. The original sink was a non-overflow bowl. The new bowl has an overflow. I thought I could just reuse the existing drain pipe, but that didn’t work for obvious reasons. The issue I have is that the hole in the granite is just wide enough to fit the drain pipe. The thickness of the drain opening on this sink is about 2”, plus the granite thickness is 1 1/2”. I cannot seem to find a drainpipe (with overflow) that will fit through the bowl and granite counter to allow me to both tighten the drain fitting and secure the bowl to the top of the granite.
I went to Lowe’s where I purchased the vessel sink. The employee in the plumbing department said that the granite opening was too small. He said that I am supposed secure the drainpipe to the vessel bowl first, then place it on top of the granite and secure it with silicone adhesive.
I did happen to find a website that sold extra long threaded drain pipe for a pop-up drain (Jaclo) for $150. This is more than this paid for the vessel. Any suggestions?

 

[Terry H]

Bronze Bathroom Decorative Sink Drain https://www.lowes.com/pd/Keeney-Bronze-Bathroom-Decorative-Sink-Drain/1000422959

They have them.

 

[Sponsor]

 

[Terry]

With the overflow drain, you will need a bigger hole in the counter.
They make a masonry bit for a jigsaw.

 

[bimfi122]

Thanks Terry. So, the guy at Lowe’s was right? I secure the drain pipe to the vessel, then drop it onto the granite with a hole big enough to accommodate the nut on the bottom of the connection. Would a hole saw designed for stone be quicker and or cheaper? Thanks again.

 

[Terry]

Using a hole saw without a pilot can be difficult. I have sometimes put some thin plywood down so that I have a place for the pilot.

 

[bimfi122]

I thought about drilling a hole in the granite counter but was concerned about cracking or chipping the counter. I came up with an idea that I would like to run by you. The actual pop-up drain tailpipe tightening nut will fit in the hole but the lip of the nut is stopped by the tight diameter of the hole. This leaves a gap of roughly 3/8" (.375") above the counter. the flat diameter of the vessel sink is roughly 9.5". My thinking is that I cut a spacer that is 9" round outside diameter and a center hole of 3" diameter. This will give the vessel something to rest on and leave room for the tailpipe to clear.

I purchased a 12" X 12" by 3/8" sheet of HDPE which I want to use as the spacer. The problem that I am encountering, after I purchased it, is that I am told that nothing will adhere to the HDPE. I was hoping to use silicone adhesive to bond the spacer to the sink, then to the granite counter. I haven't tried doing anything with the sheet yet other than drawing the two circles onto it.

Is it true that HDPE does not easily glue to anything?