Nervous about drilling...

[Rubasu]

I think I will be able to drill just fine, but I ordered an overflow that has two 1" pass through bulkheads. They were supposed to include a template, but they didn't and now I need to figure out where to put the holes.

The only thing I can think of is to put the external box on the back and trace the holes. But is there a way to make a "guide" for the bit so it doesn't shift and stays exactly in place where the holes need to be?

(Sorry for the probably dumb question...)

[ColoReefer970]

I'd recommend using a drill press, it's going to jump around otherwise..go slow..practice on an old scrap tank top or something first

[tzylak]

I hope you are talking about acrylic, not glass. I don't know about doing the latter.
Maximize the space between the individual holes and from walls. Consider the outside diameter of the nut, PLUS the wrench to tighten it, PLUS the swing of the wrench handle, at least 60 degrees (360 / 6 sides of the nut).
For some reason drilling into the sump is sooooo much less stressful than drilling into the DT. . . . . Good luck!

[MorganAtlanta]

You don't need a drill press. A portable drill is enough.
Cut a hole in a piece of wood first and clamp that on to serve as a guide.
If your tank is big enough, start on the inside of the glass for about 1/16" then switch to the outside-- you'll get a cleaner finish.
Go slow.
Keep the bit a little loose in the socket so that it will spin if it bites in.
Watch several youtube videos.
This one is similar to what I have done: https://www.youtube.com/watch?v=ZSgADDMcX8M

[madweazl]

I drilled a tank for the first time about a year ago and was so surprised at how easy it actually was. I put some masking tape down and traced the holes from the box onto the glass. I used one the guides (http://www.rockler.com/portable-drill-guide) and went for it. No issues with the drill wandering at all and the holes lined up perfect. I just went slow and let the bit do the work. Also placed a folded towel on the inside of the tank to catch the piece of glass and absorb the water that came down with it.

[Ron Reefman]

You don't need a drill press. A portable drill is enough.
Cut a hole in a piece of wood first and clamp that on to serve as a guide.
If your tank is big enough, start on the inside of the glass for about 1/16" then switch to the outside-- you'll get a cleaner finish.
Go slow.
Keep the bit a little loose in the socket so that it will spin if it bites in.
Watch several youtube videos.
This one is similar to what I have done: https://www.youtube.com/watch?v=ZSgADDMcX8M

+1
This is exactly the way to go IMHO. I started drilling tanks about 5 or 6 years ago and now I do it for a lot of members in my local club. It's not hard, just don't rush and drill from both sides if at all possible. You'll get a cleaner, no chip on the edge of the hole finish.

[billdogg]

You don't need a drill press. A portable drill is enough.
Cut a hole in a piece of wood first and clamp that on to serve as a guide.
If your tank is big enough, start on the inside of the glass for about 1/16" then switch to the outside-- you'll get a cleaner finish.
Go slow.
Keep the bit a little loose in the socket so that it will spin if it bites in.
Watch several youtube videos.
This one is similar to what I have done: https://www.youtube.com/watch?v=ZSgADDMcX8M

+1
This is exactly the way to go IMHO. I started drilling tanks about 5 or 6 years ago and now I do it for a lot of members in my local club. It's not hard, just don't rush and drill from both sides if at all possible. You'll get a cleaner, no chip on the edge of the hole finish.

What they said. I use duct tape on the inside to keep the plug from falling and cracking the other side of the tank. (Don't ask how I learned that would happen)

I use a piece of scrap plywood or other thin stock to drill the template hole. Once the hole in the glass is started, I remove the template and make a dam using plumbers putty to contain the water used to cool the bit. Go slow - a cordless drill on the lowest clutch setting works great. Expect it to take 10+ minutes/hole.

As for where on the tank - the general rule is no less than 1 hole diameter from any edge or other hole.

Don't forget to verify that the glass IS NOT TEMPERED!!! (Don't ask how I learned that rule either!) Stickers be damned - check for yourself. Often times with commercially made tanks the glass they use is sorta mix n match, so CHECK FOR YOURSELF! (google "how to see if glass is tempered")

After the first one, you'll be a pro.

good luck!

hth

[Rubasu]

Thanks for all of the responses! I think my main issue is with not having the guide. I guess I will do the holes in a piece of wood first and clamp that to the side of the tank. Thanks!

One last question/verification - I have to get a wood cutting bit for the wood and not use the diamond plated one used to drill the glass, right?

[Bent]

Your making a big deal over nothing. If you can drill a hole in a board, you can drill one in glass. It's that easy.

[lnevo]

I don't see any reason not to use the diamond bit through the wood.

[Volcmreefer]

I ordered the same size of the diamond bit on Amazon
. Super cheap. Using a template beats having to buy a drill press if you ask me. Good luck!

[Rubasu]

Bent - I'm not nervous about actually drilling - Just the hole placement. I got the Modular Marine overflow so the bulkheads are a set distance apart and I would hate to be 1/8 in off or something. I was more looking for ideas for a template than anything.

And thanks, I'll just use the same bit for the wood template.

[billdogg]

I prefer to use a hole saw designed for wood to drill the template hole(s) so as to not gunk up the diamond bit.

Use a piece of scrap that will fit inside your overflow box and trace the outlines on it so that you get the spacing correct.

[madweazl]

I don't see any reason not to use the diamond bit through the wood.

I cant even imagine how long it would take to drill through wood with a holesaw made for glass (no teeth).

Definitely recommend using a holesaw made for wood if that is the route you're going.

[Rubasu]

Just finished! First time, so the inside chipped a little. I put the overflow together without the gaskets and everything lined up. These chips are fine, right?

[thegrun]

It looks good. You're an expert now!