[Ratpack]

I want to install a coast to coast overflow in my tank but I want to keep it as small and as close to the top of the tank as possible. I really hate eating up any usable area with a box. So, how close to the edge of the glass can I drill my holes for the bulkhead? I plan to use 1" sch 80 bulkheads, so the hole is 1 7/8" in diameter. I can figure out the rst of the overflow, once I know the limit on my hole placement.

Thanks!!

[Randy]

I recall being told to keep all edges of your hole saw at least 3" away from any glass edge and 3" away from any other hole drilled.

That's what I did.

[flgoose]

I drilled my at 3" to the center of the hole and it works just fine. I asked a local big glass supplier and they told me that the hole does not weakens the glass as long as you don't have cracks after drilling. My overflow boxes are 4" x 9". That gave me enough running lenght overflow to supply the pump adequatelly.