Drilling glass tanks for bulkheads

[iceman]

I just had to post this after doing it myself.  I just drilled a 20g AGA tank for a 1-inch bulkhead using a dremel tool in 30 minutes (the next one will definitely be quicker since I won't be as cautious).  I had the 20g laying around and figured I'd try it and if it broke..no big deal.  But now, I have a 20g tank to use as a refuge.  I put the hole in the back panel in the upper corner.

 

I've been following a post on ReefCentral where a guy drilled his 20g tank fully setup and fish in it.  I thought he was crazy, but after doing this, I wouldn't hesitate doing it myself.  The thread is on the RC do it yourself forum.  The members name is thomor25 and the thread was from 8/28/2003.

 

The thread states that 20g tanks and above are much easier than the smaller tanks, but they can be done the same way.  One just needs to use some care.

 

What you need is a dremel type tool.  I have a variable speed one, but only used the highest setting for this.  You also need the dremel diamond point bits (the post uses #7134 and #7103...one is a round bit and the other is a tapered bit).  I found a set of them at WalMart (both the round tip and the taper tip) #7150 for $5.97 total (comes 1 of each in a pack).  You will also need a water spray bottle and towel, a sharpie marker, and the bulkhead that will go in the hole.

 

First, use the rubber gasket from the bulkhead and trace the inside of the hole using the sharpie.  I did it on both sides of the glass as the working side gets wiped away.  Next use the round tip bit (you may need a smaller collet for the dremel to hold the bit or use scotch tape on the bit to cause it to fit tight) and start grinding away a small circle inside the circle drawn with the gasket.  I created a circular depression about 1/4" in diameter and kept grinding away.  As glass dust (silica) accumulated on the bit, I would spray it with water.  I ground the 1/4" hole all the way through the glass.

 

Next, I used the tapered bit to cut.  It would help if you have the attachment for the dremel that allows you to rest it square on the tank, but I did it freehand.  Start by putting the bit into the 1/4" hole and moving the dremel up and down to grind away at the glass.  Move the dremel a little at a time towards the bulkhead gasket circle.  Continue moving it up and down along the line and you will basically grind away the hole.  As I indicated above, it took me 30 minutes to do the 1" hole but that was because I was cautious.  The next time will be alot quicker.  When you get all the way around, go easy and don't push too hard.  Let the bit grind away the last bit of glass and a circle will fall out and all you have to do is fit the bulkhead into the hole to see if it catches anywhere then just gring away at the sides.

 

It is amazingly easy.  I read the post (all xx pages of it) where everyone says it was easy and figured I'd try it on this spare tank.  If I broke it, no big deal.  Now having done it, I can say it was amazingly simple and I wouldn't hesitate to do it again.  If someone wanted a larger sump or refuge with several holes, it would be very easy to do.

 

I'll be happy to answer any questions/concerns about my experience.  I just had to post this after doing it and finding it really simple.  Be careful not to drill tempered glass bottoms.

[HowardofNOVA]

Bob,

IMHO, The guy was crazy to drill a hole into his tank while fish where still in it.

But that being said, the process isn't that difficult, just need patience. Mike at TRT said tanks over 20g over not a problem, but under can break VERY easily. Be carefull.

Howard

[craby]

I successfully drilled a 5 gal tank today, but... broke it when putting the bulk head through the hole. A little too tight of a fit.

[ReefMon]

Thanks Bob!

 

I remember reading the thread thinking that it sounded like too much work to be worth it, but obviously not.  I might be needing to drill several tanks in the near future, and might try it.

 

Happy Reefing!

Glenn