# Drilling Glass - drill speed??



## titansfever83 (Jan 10, 2011)

I was hoping some of the experienced could chime in on some details of glass drilling.

I know about making a "pond" with water to keep the glass and bit cool. And to start at a slight angle and slowly move to 90 degrees. My question is drill speed and is it necessary to stop for a few seconds while drilling to help cool the glass even more.

Do you guys drill at half speed or full speed once you've made a groove in the surface of the glass?


----------



## NVfrogger (Apr 10, 2011)

I drill about half speed and I stop and add more water about 1 minute or two after I start. I keep adding water every minute or so until the hole is made. The secret is not pushing down to hard, just let the weight of the drill be all the pressure that is applied. Hope this helps.


----------



## dfrmav (Feb 22, 2011)

NVfrogger said:


> I drill about half speed and I stop and add more water about 1 minute or two after I start. I keep adding water every minute or so until the hole is made. The secret is not pushing down to hard, just let the weight of the drill be all the pressure that is applied. Hope this helps.


Start out at about 1/3 to 1/2 speed to get the initial cut, and once you've raised the drill to the point where it's cutting a full circle, you can bump up the speed. I've never gone full 100% speed but I'd say about 75% is good. And yes, don't push down too hard.


----------



## ZookeeperDoug (Jun 5, 2011)

I've drilled hundreds if not thousands of tanks by hand this way. As has already been mentioned, you don't need full speed, just let the weight of the drill do the work.

What I also do, is add a very small amount of antifreeze to the pool. Be careful if you have dogs or cats around and only add enough that you can still see what you are doing. Of course be sure to rinse well. I was taught this way at the first aquarium shop I worked at. Supposedly the friction is reduced. We were drilling tanks that were sometimes 1.25" glass bottoms!


----------



## holidayhanson (Apr 25, 2007)

One thing I did and was really helpful is to build a jig with cardboard.

I cut a hole in a few layers of cardboard the same size as my hole was (diamond coated hole saws from HK on ebay were cheap). I taped the cardboard onto the glass where I wanted my hole. I made a tiny water reservoir with plumbers putty and the cardboard on top of this. The cardboard will keep the hole saw centered on where you want your hole. Without it is hard to get your saw cutting in the same spot. If you can rig it up a drill press would be the best for this job. Create support on the under side of the glass too. Once you get the hole started and a grove set you can remove the cardboard. Then build up the plumbers putty dam and keep it filled with water. Rinse it out with fresh water to wash away the glass and diamond dust.

I have not heard about starting at an angle. In my opinion I think you want to maintain an evenly cut hole so when you get to the other side you punch through all at once.

I drilled through a 90 gallon tank. I made it almost all the way through and then it cracked right at the very end. I think I was getting excited and was probably on my 3 or 4th beer by that time. I was pretty bummed...I made a glass/silicone patch over it and it has not leaked a drop. 

Go slow and only the weight of the drill. I went about as slow as I could hold the drill....use a strip of tomato vine velcro to make a strap to hold the drill on at the speed you want. Holding it with your finger you will certainly want to go faster and faster. The velcro will hold the drill on just where you need it.


----------



## Ed (Sep 19, 2004)

I use a jig I made using lexan and oil based modeling clay. The modeling clay acts both as the dam and the control to get a straight hole through the glass. It is easy to make and easy to use. Make sure the clay is warm so it will stick to the glass and you simply push it against the glass to seal it and then add water. I use a large drill and the weight of the drill is more than sufficient to provide all of the weight needed to drill through the glass. 

Ed


----------



## Pumilo (Sep 4, 2010)

I work with glass for a living for 20 plus years now. I use a lubricant/coolant designed for drilling glass. Since you guys don't have that around, Zookeeper Doug's suggestion of using antifreeze is spot on. Antifreeze has similar lubricants in it. Use a 50/50 mix. Clean it well afterwards and don't forget what he said about dogs and cats. They like to drink it and it is poison! I don't like the cardboard template idea as it could keep the coolant from flowing freely into your cut. Maybe that's why his cracked? Starting at an angle is a great way to drill a hole freehand. As far as drill speed goes, it can vary quite a bit and still be successful. Drilling at a slower speed will extend the life of your bit, but drilling at a faster speed is much faster. If you read through this, it will answer all your questions including ones you didn't realize you had. http://www.dendroboard.com/forum/parts-construction/58594-how-drill-your-glass.html


----------



## RyanD (Jul 18, 2006)

Did you get your drill bit from ebay? I have purchased two from different sources on ebay and the quality of one of them was horrible. It only lasted for two holes while I have been able to drill about 6 with the other one.


----------



## ZookeeperDoug (Jun 5, 2011)

I got my hole saw from Bulk Reef Supply. It was more than sufficient to drill 12 holes and I'm sure I could do more. I used 1/2 bulkheads and the saw was only like $8.

Also, for a very ghetto damn, take a large washcloth, wet it and roll it into a tube, then wrap around your intended hole. It works but only if you're drilling thin glass as the water will leak out slowly.

If you're planning to drill a lot of holes I'd really recommend a drill press guide for hand drills and a drill ring. The hand drill press will give you almost a perfectly strait up and down start and now need to start at an angle and the ring is just a nice clean damn for your water without the mess of putty. Only really worth in investment IMO if you plan to do quite a few holes.


----------



## Pumilo (Sep 4, 2010)

RyanD said:


> Did you get your drill bit from ebay? I have purchased two from different sources on ebay and the quality of one of them was horrible. It only lasted for two holes while I have been able to drill about 6 with the other one.


No, I get mine from my wholesale supplier, CR Laurence, but they won't sell to the public. Did you use a proper coolant and lubricant? You can ruin even a good bit with only one hole if it's done dry.


----------



## titansfever83 (Jan 10, 2011)

wow, I believe I'm good to drill my first hole! Thanks for all the info and thanks for the link Pumilio. 

My bit was also purchased from Bulk Reef Supply just because I purchased my bulk heads, fittings, RO unit from them.

My bit should be here around Tuesday so I'll be tinkering with other parts of my build until then.

Thanks again for all the replies


----------



## clownfrog (Jan 15, 2012)

Here are the speeds that came with my glass drills:

1/2 800RPM
1" 500RPM
2" 250 RPM
3" 160 RPM

I followed the above and drilled all my holes with no problems. My drill has an RPM guage so it was easy.


----------



## RyanD (Jul 18, 2006)

Pumilo said:


> No, I get mine from my wholesale supplier, CR Laurence, but they won't sell to the public. Did you use a proper coolant and lubricant? You can ruin even a good bit with only one hole if it's done dry.


For both drill bits, I was drilling in the bath tub with the cold water on full blast. The one worked great that way while the other wasn't as good. Probably not the best setup, but it worked.


----------



## Pumilo (Sep 4, 2010)

RyanD said:


> For both drill bits, I was drilling in the bath tub with the cold water on full blast. The one worked great that way while the other wasn't as good. Probably not the best setup, but it worked.


I have not tried a drill bit from Bulk Reef Supply but they run a reputable business and I have found their other products to be serviceable. Hopefully that's not violating the feedback policy.


----------

