increasing hole diameter in glass

[Mark]

Hi there,

Anyone ever try to increase the diameter of holes predrilled into the side of their tanks? I have two 1 inch holes in the top back corners of my tank. With the bulkheads, the output size is about 3/4 pvc. I would like to increase the diameter of the hole to accommodate larger bulkhead and consequently larger pvc. Could I use a rotary tool or a dremel to do this?

[Adam]

Mark,

You could not do this with a dremel or similar tool.

You might be able to do it by getting the appropriate size glass hole cutter, clamping a scrap over the existing hole and drilling throught both pieces. I would still consider this to be very risky.

Adam

[harmonic]

I have cut holes and/or routed them out larger in glass lids with a dremel & it's stone grinding wheel. It did not leave the edges as smooth as I would have liked, but did do the job.

[Mark]

Thank you. I needed an excuse to buy a dremel, and now I have one!

[harmonic]

I had to cut this out to accommodate the output pipe of a Lifereef HVS2-24 skimmer. The skimmer's down the road, but the hole's still there. :lol:

[harmonic]

Oh, btw... I have the larger dremel rotary saw. I would not recommend it to anyone. It is improperly designed - top heavy. The imbalance causes the saw to want to "twist" as it's running due to the off-kilter centrifugal force. I am positive it was not the fault of any cutting bit either. I tried some very expensive & well balanced drill bits in it as well as the free bits it comes with. My saw could just be a fluke, but I still have no faith in them. The smaller hand held dremels are great little tools though.

[rvitko]

A good stained glass shop will have a glass grinder bit for use in a hand drill. It is still very risky but I have done it before.

[AquAddiction]

I bored out a 1" hole to accomodate a 1.5" bulkhead using a diamond-coated sanding drum (~$8) and it worked like a charm. I just attached the sanding drum to a power drill traced the hole in the glass and sanded away. I checked every now and then until the bulkhead fit snugly in the hole. Make sure to use silicone when installing the bulkhead as a percautionary measure. This link was very helpful in my endeavor, check it out:

http://www.nano-reef.com/forums/showthread.php?s=&threadid=2982