Where to drill aquarium

Kasey Grohowski · Feb 11, 2019

Planning on drilling my 220 this week or next week, putting in a modular marine low profile overflow, rated for 2400 gph. I'm planning on putting it close to one of the corners on the tank. Does it matter how close to the edges I drill? I am also using a ryobi hammer drill corded. Any advice? Also can I achieve 2200 gph with this overflow?

Ron Reefman · Feb 11, 2019

I think the general rule is to leave any hole a distance from an edge or another hole at least the diameter of the hole away. So a 1" hole should be at least 1" from an edge or another hole.

Don't use the hammer setting on your drill, just use it like a regular drill. Run it slow and take your time. It helps a lot if you have a guide or jig attached to the tank to keep the drill bit centered. Don't add much pressure on the drill and even less when you get near the end. If you can drill from both sides you'll avoid any chance of the glass 'chipping' when the drill bit punches through. If you can't drill from both sides, add some strong tape to the side of the glass you aren't drilling or use a reverse clamp to hold a block of wood against the back side.

Kasey Grohowski · Feb 11, 2019

Ron Reefman said:
I think the general rule is to leave any hole a distance from an edge or another hole at least the diameter of the hole away. So a 1" hole should be at least 1" from an edge or another hole.

Don't use the hammer setting on your drill, just use it like a regular drill. Run it slow and take your time. It helps a lot if you have a guide or jig attached to the tank to keep the drill bit centered. Don't add much pressure on the drill and even less when you get near the end. If you can drill from both sides you'll avoid any chance of the glass 'chipping' when the drill bit punches through. If you can't drill from both sides, add some strong tape to the side of the glass you aren't drilling or use a reverse clamp to hold a block of wood against the back side.

Yeah using the drill mode of course, what do you mean by chipping? I was planning on duct taping the bottom side of the tank and putting a towel below it just in case.

Kasey Grohowski · Feb 11, 2019

Ron Reefman said:
I think the general rule is to leave any hole a distance from an edge or another hole at least the diameter of the hole away. So a 1" hole should be at least 1" from an edge or another hole.

Don't use the hammer setting on your drill, just use it like a regular drill. Run it slow and take your time. It helps a lot if you have a guide or jig attached to the tank to keep the drill bit centered. Don't add much pressure on the drill and even less when you get near the end. If you can drill from both sides you'll avoid any chance of the glass 'chipping' when the drill bit punches through. If you can't drill from both sides, add some strong tape to the side of the glass you aren't drilling or use a reverse clamp to hold a block of wood against the back side.

Also I wasnt going to add any pressure just the drill weight ( weighs about 10 pounds)

Ron Reefman · Feb 11, 2019

When the drill starts to go through the glass (as in coming out the far side) it has a tendency to flake or chip at the edges of the hole.

You can add some weight while drilling, but not much. As you start to get near the end, really back off the pressure, like you said, just the weight of the drill.

Kasey Grohowski · Feb 11, 2019

Ron Reefman said:
When the drill starts to go through the glass (as in coming out the far side) it has a tendency to flake or chip at the edges of the hole.

You can add some weight while drilling, but not much. As you start to get near the end, really back off the pressure, like you said, just the weight of the drill.

Oh okay, how can I prevent that without drilling through both sides?

theMeat · Feb 11, 2019

Not really. A lil chipping is ok, if not, drill from both sides. Use some plumbers putty to make a small barrier to act as a dam around where you will drill and fill it with water to keep the bit cool. The glass eating up is the biggest worry

Kasey Grohowski · Feb 11, 2019

theMeat said:
Not really. A lil chipping is ok, if not, drill from both sides. Use some plumbers putty to make a small barrier to act as a dam around where you will drill and fill it with water to keep the bit cool. The glass eating up is the biggest worry

What do you mean eating up? I was going to use a gasket as I heard they work better.

Ron Reefman · Feb 11, 2019

I use a big clamp that I can reverse the end so the clamp actually pushes out. Then hold a board up against the glass with the reverse clamp. A layer of tape over the back side of the hole can help as well. The most important thing is to really go slow at the end, as the hole saw is starting to cut through the back side surface.