Alternate method of tank drilling 120gal.

[Fl_Seagull]

Having made stainglass, the idea of drilling my own tank did not seem very hard. After all, glass grinding is glass grinding.

EDKHosting's posting made is sound easy. (check here for the details). But, he was drilling a 20 gal not a 120 gal and the glass thickness is quite different.

While I don't doubt someone could drill 3/8" glass with a #7134 dremmel bit, I doubted that I could in less than 3 hours. My dremmel can't run for more than 10 minutes with out getting too hot to hold.

Here are the bits that I used instead of dremmel bits.

Two possible bit types.

The left one shows the diamond part has failed and come off the bit. It is designed to drill glass. It is a 1/4" bit designed to screw into an adapter which then slips onto the 1/4" shaft of the glass grinder. Using a 1/4" hex to 1/4" socket adapter, I was able to use the grinder bit in my electric drill. Since drills are not made to run continuously, the drill heating up will be the limiting factor in completing this task. I found I could not run the drill longer than 15 mins without stopping and letting it cool. But, i have two drills .

The right bit is designed to screw into the top of the grinder post. To use it in a drill it has to be screwed into a standoff with 8-32 threads.

The biggest advantage to both of these bits is that you are not going to bend them. Thus you can apply the force necessary to work your way through 3/8" glass.

I used EDKHost'ing method and it is still valid. The bigger bits just let you apply more force.

Here is one end showing the different bulkeheads and the finished holes.

Here is the other end showing how far I got before my bit failed. The bit shown on the tank is a 7/8" bit I use to clean up the holes (and enlarge them to fit the bulkhead ).

 

[Anonymous]

if you take modeling clay and build a dam around where the hole will be, then fill the pool with water, the glass won't get too hot.

However, you have to be really careful if you're using an electric drill. water and electricity don't mix too well.

B

 

[Fl_Seagull]

...you have to be really careful if you're using an electric drill. water and electricity don't mix too well.

B

Point well taken. I started using my portable drill. It took 4 battery charging to complete the first 2" hole. I then went to switching between my portable and corded drill. The corded drill is plugged int a GFI and the drill is double insulated. Short of dropping the drill into the the small container of water I was using the risk is small.

As to the clay dam... this work well when using glass drills.

With the method I am using the water drains through where you have already drilled, so the clay dam helps but I find it just gets in the way for me. This is mainly because I am using a sponge to apply water, not a squeeze bottle.

 

[Ricpan]

Best way and easiest is a diamond core bit. 1 3/4 for a 1" bulkhead. Use the dam method and a little water antifreeze mixture. You can do a hole in about 2 minutes and the bit will last many holes if you don't get it to hot. Bits can be bought online for about $50 at Ameri glass www.shopsmartxpress.com/AmeriGls/m9.htm. Cheapest place I've found.