Enlarge a glass hole

[atnet360]

Has anyone drilled a slightly larger hole in place of an existing hole in glass...

Ive got a 180 gallon reef ready tank with an internal overflow, but the overflow is drilled for one large drain and two 3/4 in returns. I would like to do a bean animal overflow (and run the returns through the back) but don't feel comfortable using a 3/4 emergency drain. So I'm considering drilling out the holes slightly larger to accept either 1 in or 1.25 in bulkheads.

I've drilled glass before, not worried about that, but I'm a little worried about the holes chipping out because the new hole will only be a couple of millimeters bigger than the existing hole.

Here's a shot down the overflow. The middle hole will accommodate an 1.5in bulkhead, the two on the sides will fit a 3/4 in bulkhead.

Thoughts?

 

[Reef man 89]

I want to do the same thing from 1/2 to 3/4. Following along

 

[315wall]

That is a lot of holes in a small, space. Are you drilling from the bottom? Do you have a jig to hold your drill ? I've done it before but the hole was much larger than the hole I was replacing or drilling outside of.

 

[atnet360]

That is a lot of holes in a small, space. Are you drilling from the bottom? Do you have a jig to hold your drill ? I've done it before but the hole was much larger than the hole I was replacing or drilling outside of.

I would be drilling from the bottom. Yes, I have (or would make) a jig.

 

[Scratch08]

Has anyone drilled a slightly larger hole in place of an existing hole in glass...

Ive got a 180 gallon reef ready tank with an internal overflow, but the overflow is drilled for one large drain and two 3/4 in returns. I would like to do a bean animal overflow (and run the returns through the back) but don't feel comfortable using a 3/4 emergency drain. So I'm considering drilling out the holes slightly larger to accept either 1 in or 1.25 in bulkheads.

I've drilled glass before, not worried about that, but I'm a little worried about the holes chipping out because the new hole will only be a couple of millimeters bigger than the existing hole.

Here's a shot down the overflow. The middle hole will accommodate an 1.5in bulkhead, the two on the sides will fit a 3/4 in bulkhead.

Thoughts?

I have done it successfully with 6 holes...nerve-wracking for sure. You need to make sure that bottom pane is not tempered glass if you decide to try it. I used a piece of plywood and drilled a hole the same size as my glass bit, clamped it to the outside of my tank and a second piece on the inside as a backer on the glass..then just let the weight of the drill carry the bit through the glass.

 

[John08007]

Maybe put a piece of duct tape on the inside so that you can do the clay, water technique from the bottom

 

[BZOFIQ]

You need a jig to hold the bit in place. Water for cooling - slow and steady wins the race.

That is like someone already mentioned ......after you ensure the bottom isn't tempered.

 

[AlexG]

I have done it before to go from 3/4" to 1" and 1" to 1.5". Double check the glass is not tempered. A jig is needed if a suction cup drill press is not being used. Also use tape on the glass to hold in the cutting coolant and let the bit do the work. Also tape with a piece of wood or plastic clamped in place can help to avoid chipping as the bit passes through the backside of the glass.

 

[theMeat]

Take it slow, you can do it. A jig can help

 

[315wall]

I second some good tape like duct tape, also let the cutter and weight of the drill do the work. No races to win here by going fast.

 

[Shon]

About to tackle this myself. 29g aqueon. I drilled the back years back, realized the template from eshoppes made it to low in the tank. So I decided to try to use it as a live food tank.

I drilled the bottom with wrong bit at first. The holesaw fit over the base of the bulkhead, so I was like, yup that is it. Nope, too much slop play and I do not trust it, especially since it is on the bottom. Wish my glass hole saws had writing on them, or knew where my calipers were at. It was a 2 inch holesaw when i ment to use the slightly smaller metric. Made a template with 1/8inch scap wood. It jumped a bit at start but am not worried about unsightly scratches.

Now I am using the 1.5 holesaw bit that came with the eshoppes overflow, bought an additional 1.5 bulkhead.

Bout to start drilling..

 

[BroccoliFarmer]

Who you calling a glass hole?!?

 

[Shon]

And... SUCCESS

I wanted a glass donut, should have put a towel down..

Came out great!

Really no different then drilling normally, just more water splashing on my feet.

10/10 Would do it again

 

[TangerineSpeedo]

if you are just going slightly bigger, make a template to the size you want. Then just take a dremel with a sanding drum. the template is just a guide for you.

 

[Derrick0580]

Yeah, if the hole isn’t much big I would think a glass file or some sort of sander would be the safer bet.

 

[Shon]

I found the dremel in my garage mess, but not the various bits. Need to really work on organizing. Used what I immediatly had. Never dremeled glass before, maybe in the future.