questions on drilling glass

For all you tank and glass experts (I lack basic glass knowledge) basically how can I tell if a tank can be drilled? From what I understand, tempered glass cannot be drilled. Is there any other types and how can I tell if it is or not? The reason why ask; I want to upgrade to a larger tank and I can find great deals on used larger tanks but most are not reef ready. I wouldnt mind trying to get right tools and knowledge to try drillling but do not want to purchase a tank that I can't even try. Unless you tell me that drilling a tank is a skilled art and shouldn't even try. I find myself handy around the house but this is not my expertise. Thank you

 

You will need to get polarized sunglasses and shine a strong light on the glass you wish to drill. You will need to look at the glass at a 90 degree angle to the light source. If the glass looks like it has shaded and light areas it is tempered and can not be drilled.

Most tanks only have the bottom pane tempered. If you can identify the manufacturer they should be able to tell you if the glass to be drilled is tempered.

If it good to drill you will want to make a template from wood that is slightly large in diameter than the outside of the hole saw you need to use. Mount the template on the outside of the tank and a solid piece of wood in the inside opposite the template and secured with clamps. Go slow and with light pressure. It should take a couple of minutes to drill the hole. Glass Holes has a very nice kit with instructions on their site of how to do the deed.

 

Thanks for the info. I just checked out Glass Holes site and wow makes projects like these much easier. Thought I would need to build own overflow boxes and such but don't have to with their stuff. I love projects. I am a hands on guy stuck in a desk job.

 

I have drilled a few tanks and it is very easy. I run water across my drilling surface with a hose when i do it. What size tank are you looking for?