Drilling glass, from inside or outside of tank?

[FISHNUTS]

Did a search and with over 500 threads on drilling glass, I could not find this question answered.

Is it best to drill a tank from the outside going in or from the inside going outwards?

Many videos show people drilling from the outside but is this really the best way? My biggest concern is the slight chipping that occurs at the very end of the drilling process. Is it better to have the chipping on the inside of the glass or outside?

Guessing that it being for an overflow hole near the top won't matter much but how about for a hole in the bottom of the tank?


Am I being to anal?

Thanks
Shawn

[fltt]

Both,
First u start on the outside, go about half way then as long as the drill fits finish on the inside.

U should make a jig so that you will be able to line it up exactly and the bit won't ride.

If thats not an option then you can put tape on the inside to limit the chipping.
Make sure as you get to the end you let the driil do the work no pressure from you.

Good Luck

[kookie_guy]

Lining up your hole from the opposite side will be difficult, and you may get an off-center hole. Personally, I've had great luck with my method of drilling holes. I start with a piece of plywood, drill a hole slightly bigger than your glass drill. This prevents the glass bit from wanting to wonder around. Also take a piece of plywood, and clamp it to the underside of the glass, making sure it's nice and secure. Finally, let the drill bit do the work. Don't put any pressure on it other than just the weight of the drill. When you get to the end, the plywood will provide counterpressure and give you a much cleaner cut.

[tangelo_]

You can watch a video of it being done on www.glass-holes.com

[FISHNUTS]

Both,
First u start on the outside, go about half way then as long as the drill fits finish on the inside.

U should make a jig so that you will be able to line it up exactly and the bit won't ride.

If thats not an option then you can put tape on the inside to limit the chipping.
Make sure as you get to the end you let the driil do the work no pressure from you.

Good Luck


Yes I was thinking of doing the same thing. Might stick with this idea.
thanks


Should have also mentioned that I have drilled about 50 holes in the past couple years. Just wanted to know if there drilling from the oustside in made a difference whent it came to chipping the glass towards the end.

sl

[gspgretchen]

I drilled mine with glass holes kit from inside. Tank was over half full of water and live stock. Drilled 2, 1.5" holes in less than 5 minutes. I was either lucky or good(lucky).

[tinkerman]

I have done it both ways but like from the inside out better, doesn't mess up the seal on the bulk head with impressions from any chipping if you went outside in.

[ghellin]

I drilled a 46 from the outside and everything went quite well, no chipping.

[tkeracer619]

No it doesn't but you want something on the other side of the glass so when the bit makes it though the glass plug doesn't break away when the glass gets thin.

[FISHNUTS]

Thanks for the replies folks. :)
sl

[Jack01]

Ive drilled all my tanks from the outside with no problems.