Step-by-Step: Drilling Holes in Your Glass Tank for Bulkheads

This thread really got me interested in drilling my own tank and I bought the diamond coated bit and was practicing on a spare 10 gallon I had. So far both holes I've attempted have cracked the glass. Has anyone else tried on a 10-gallon tank? I'm hoping it's just because of the really thin glass used. I will eventually be drilling a 30 gallon tank with a bit thicker glass.
 
You'll have to be extremely careful with a 10 gallon tank, the thinner the glass the more difficult it is for sure. I've never attempted a 10 gallon, but my 150 was easy, nerve wracking but easy...
 
I drilled the hole this weekend in a 30 gallon long and it worked like a charm. A bit scary hearing that glass grinding, just waiting for the crack again, but it worked great. I guess that 10 gallon glass is just too thin.
 
<a href=showthread.php?s=&postid=10784283#post10784283 target=_blank>Originally posted</a> by philly180
what size holes would you drill for proper flow in a 150g oceanic? and how many? dying to know so i can purchase the bits!

If it was me I would do 2 1.5" drains. Depending on the brand/style bulkhead you go with, the hole will a around 2 5/8".

That's just for draining into the sump. If you're doing closed loop you'll need other/more holes than just those 2.
 
Ditto Goldstripes recommendation-- it obviously depends on how much sump flow you plan on running, I plan on drilling my 135 for (2) 1 1/2" bulkheads.

@ namwodahs -- I practiced my first drilling on a 10 gallon... was very thin glass but drilled just fine... keep a very light touch on the drill-- it took me about 3 minutes to drill my hole (45 mm hole saw for a 1" bulkhead).
 
Let me tell you my recent experience in drilling two 38 mm holes in a 10 gallon I am using for a frag tank...I first bought a 10"X10" piece of glass about the same thickness from HomeDepot to practice on and it was the right thing to do...The drill bit (from the Hong Kong guy) skated all over, making a scratched mess, and I cracked the glass in 2 minutes. From this I learned to clamp a inch thick piece of wood onto both sides of the 10 gallon. I also used a hole saw to drill a 1 inch hole in one of those pieces of wood to use as a guide for the diamond drill bit. The hole in the wood was flush against the glass and it held water in like a pond...Then I used my power drill on the lowest torque setting and went slow. I also taped ducttape on the back side of the glass. Anyway, ,I took 10 minutes a hole and was real cautious, but the results were beyond good! Two perfect holes, with only the tiniest of little imperfections around the edges. Having the extra support on the glass and using the "guide hole" made all the difference for me in drilling this thin glass.

Thanks for this thread, it is full of fantastic information. Everything I did I read on this thread...
 
<a href=showthread.php?s=&postid=10796160#post10796160 target=_blank>Originally posted</a> by psyrob
Let me tell you my recent experience in drilling two 38 mm holes in a 10 gallon I am using for a frag tank...I first bought a 10"X10" piece of glass about the same thickness from HomeDepot to practice on and it was the right thing to do...The drill bit (from the Hong Kong guy) skated all over, making a scratched mess, and I cracked the glass in 2 minutes. From this I learned to clamp a inch thick piece of wood onto both sides of the 10 gallon. I also used a hole saw to drill a 1 inch hole in one of those pieces of wood to use as a guide for the diamond drill bit. The hole in the wood was flush against the glass and it held water in like a pond...Then I used my power drill on the lowest torque setting and went slow. I also taped ducttape on the back side of the glass. Anyway, ,I took 10 minutes a hole and was real cautious, but the results were beyond good! Two perfect holes, with only the tiniest of little imperfections around the edges. Having the extra support on the glass and using the "guide hole" made all the difference for me in drilling this thin glass.

Thanks for this thread, it is full of fantastic information. Everything I did I read on this thread...


The reason it probably skated all over is because you may not have started the drilling on an angle. If you start the drilling on a 45 degree angle, it creates a groove in the glass without slipping all over the place. Then you slowly transition to complete 90 degrees, using the groove as a guide. The groove will keep your bit in place throughout the rest of the drilling. It's an easier way to do it than to have to make a wooden template to clamp to the tank.
 
You know, I first tried on my test piece of glass to do the 45 degree thing, and I was a failure at it, I couldn't get it to bite and it skated all over. Maybe I gave up too early, but since the glass cracked, I decided to "dummy proof" the procedure and go with the template hole. Worked for me...
 
Again... it's pretty simple to use the inside corner of a framing square to get the hole started and no special templates, guides or the like....

Tim:cool:
 
There is actually a very simple way to get the hole started without skating. I cut a 3" x 3" notch out of a small piece of 1/4" acrylic. Place the hole saw where you want the hole to be and cozy the 90 degree angle in the acrylic up against it.Clamp the acrylic down with a couple of clamps with a backer board on the other side of the glass and have at it! Just keep the bit up against the inside corner of the acrylic until it is started. No skating. Some cautions: be patient, don't apply pressure (let the weight of the drill do the work), use a slow drill speed and flood it with plenty of water. This drilling jig will work with all sizes of diamond hole bits. I just did 4 - 1.5" holes in 1/2" glass in about 45 minutes.
 
Dang, Tim. I just saw your idea. Great minds! The acrylic might be a little easier on the diamond blade than the steel square.
 
Ted,
Your idea is essentially the same as mine, I just makes more sense to me to use what I have on hand rather than a 1 purpose tool 'cause I'd never find it the next time I needed it! I haven't had a steel square in a long time, mine are all aluminum, I do shim it up 1/4" when I need to so the coated part of the bit doesn't grab and walk but more times than not I rest it on the plastic aquarium trim instead of separate shims when I drill bottom overflow holes.

Tim:cool:
 
I just drilled my 20 and a 10. All that I did for a guide was took a 2x4 chunk and put a hole through it with a normal bit the same size as I was drilling. Then I grabbed some rubber-tipped clamps, and clamped it to the tank I was drilling. It seemed to work fine for me. The most expensive part was the hole saw, but I'm sure I'll use it again for plumbing or something some day so it's not that big of a deal.
 
Sorry I don't have time to read through all 40 pages right now (I did go back a few pages)... anybody recommend a site for 1 1/2" bulkheads (time to drill my 135 gallon tank) and hopefully with bulkhed dimensions??

I need to decide on a bulkhead before I order a hole saw.... I've noticed some fairly big variation on the OD's of larger bulkheads

Thanks
 
Savko has some good bulkheads and they provide hole sizes as well. I bought my bit from THK.com at the recommendation of others - worked great for me.
 
Thanks Mike- Savko does sound familiar to me; I must have read it in this thread a while back-- it has been about 18 months since I drilled my last hole.... I was looking at THK for the saw this time--

Just for everyone elses benefit.. it is www.thk.hk (not dot com).... hk is for hong kong (i'm pretty sure)-- site is kind of slow at the moment...
 
Wow I just read all 32 pages. This is a great thread i'm soo glad it's here. I'm stil in the research stage but I think i'll drill my 120 myself when the time comes. Thanks for all the great info! :)
 
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