drilling a tank

[Katfsh]

I have ordered a new 20 gal tall tank due to the fact that I got my old one out of the shed and it had a crack all the way across the bottom.
I am considering drilling my new one myself. I have been looking at bits anhttp://cgi.ebay.com/2-pcs-35mm-Diamon ... ZViewItemd how to do all over the net. These bits seem to be very cheap, has any one used them?
How many hole can I expect to get out of a bit? I would like to try one on my old tank first before drilling away on the new one.
Any pointers??
please help!

katfsh

 

[Anonymous]

The link does not work for me, but my guess is that they are Taiwanese diamond bit, not very high quality, but does get the work done. They should last for a dozen or so holes, but I have no hand-on experience with them. Hopefully some of us who did use it can drop a line or two.

 

[cindre2000]

I have drilled a 12 gallon Nanocube, a 50 breeder, and a 120g with the cheap foreign bits. You just have to take your time, keep up the rpms and don't use a lot of pressure.

Your mileage varies but you can expect to get a couple of holes out of each bit depending on the thickness of the glass. You can drill pretty quickly when there new, but it takes longer and longer each time.

 

[ChrisRD]

I have used the cheap eBay bits with no problems on glass up to about 1/2" thick. I got mine from this place:
http://stores.ebay.com/THK-Diamond-Tools

Ironically, I have a bit I purchased from an online glass company here in the US years ago (before the cheap foreign bits were readily available) that was about 10X the price of the THK bits, and the THK bits appear to be better build quality and seem to cut as well or better.

JME

 

[brandonberry]

I have used these bits many times. From my experience, the thicker the glass, the less chance you'll crack the tank. I've drilled several 20g tanks and have yet to crack one. On the other hand, I've drilled several 10g tanks and cracked about the first 2-3 I drilled. The key is to put very little pressure on the bit, especially when you are getting close to breaking through. I used a drill press to ensure that I was drilling staight and evenly, however I'm sure you can use a regular drill if you are careful. I keep a cup of water beside me and make sure there is always water in the groove and around the bit while I am cutting. Also, I drill rather slowly. Another benefit of the drill press is being able to set a defined speed. Keep your hand on the glass beside the bit and if you fill it getting more than just moderately warm, you are either drilling too fast or not using enough water. If you are just patient and don't rush it, you will be OK.

 

[SnowManSnow]

to help with the pressure I would stack put the tank upside down on the ground with the bottom up and stack some wooden blocks up inside that are exactly as high as your tank so that when you push down on it you are pressing on the blocks instead of against the entire pane of glass.

ive actually never drilled before, but if i do.. i think that this would help lessen the chance of a crack.

b

 

[brandonberry]

I prefer to have something directly below the glass, but I have cut both with and without this support with equal success. It does seem to cut down on a little vibration.

 

[Anonymous]

Doesn't matter, but I agree with taking your time, using lots of water. I measure and mark the hole first with a marker, then use a wooden template to hold the bit in place for the first thirty seconds with my other hand, until the groove is established, then remove the template. If you don't use a template or other method to hold the drill in place when you start, be careful the bit doesn't skip around on the glass.
Also, I cut pieces of thick cardboard to place directly under the hole I am drilling, it makes it a bit easier near the end, but it's not necessary. You will know you are getting close when the water starts to drain out of the groove. Slow down and lighten up The less pressure you use near the end, the less change of chipping the hole. Drill the tank from the inside out. And if you are drilling the bottom, make sure it's not tempered.
I have drilled a few hundred holes using a cheap, lightweight, battery driven drill from the local hardware store. Make sure your battery pack is fully charged. Electric drills are too fast.

 

[Anonymous]

So what size drill bits for 3/4" and 1" bulkheads?

 

[ChrisRD]

It depends on model/schedule of the bulkhead in question, but the required hole size is normally indicated by the bulkhead manufacturer and/or the vendor.

For example:
http://www.marinedepot.com/ps_AquariumP ... iners.html

HTH

 

[Anonymous]

Thanks.

 

[Anonymous]

I have had two people tell me to use vegetable oil as the lubricant of choice when drilling through glass. They suggest making a dam around the hole with plumber's putty to contain the oil. Seems reasonable. Anybody else do this?

 

[ChrisRD]

IMO it's unnecessary and will just make clean-up harder.

All I have ever done is run a slow trickle of water from the garden hose on the bit/cut area - never had a problem.

If you're drilling indoors the putty dam might be worthwhile to help contain the mess, but water is fine as a lubricant/cooling IME and cleans-up easily.

 

[Anonymous]

Thanks. I will stick with the water.