I am trying to cut a whole in the back of a glass block. What do you use?

Hi, Newt57!

What kind of glass block is this and how large are you wanting the whole to be, please?

Thanks!

8x8x3 1/2 inch whole

Using a Dremel Moto-Tool or other type of high-speed drill with the appropriate bit and lubricant should work.

There is some pretty good information that can be found via clicking on the following link about that.

OZ REEF - Cutting Holes in Glass

Thanks!