I got a PVC flange for my table but am uncertain about two things:
First, the inside face of the flange isn’t totally flat, it’s raised slightly in the center (which might be ok if that is used to center the flange in the hole), but the mounting holes are also raised, which, I would think would create a potential for leaks. I guess it depends on how ‘goopy’ the 3M 5200 is. I haven’t used it before, but I did get a tube for this application.
Secondly, the mounting holes are HUGE! They’re 5/8" diameter! How do you use a 1/4 bolt in this???
I’m thinking that I need to make a backing ring that the screws thread into to pull the flange tight to the bottom of the water table and that I should put the flange on my lathe and turn off the raised face, at least the raised port around the mounting holes.
What’s your advice, master of flanges?

