Drilling an extra hole

[paddyob]

Good tip on scrap piece.... Now do I have or can I find some.

Originally Posted by FishyFishy!

It's honestly not that bad at all. Have you tried to practice on a junk sheet of glass yet? If not, I highly recommend doing so. Thats what I did to get started. I drilled 4 holes before even touching my main tank. All came out great in the the Practice runs, so I did my main. Aside from a few small chips on the outside when the bit came through, all went well.

The worst part IMO is getting the hole started. I learned the best way is to brace the drill with one hand on the glass and drill, hold the bit at an angle so that just one tiny part touches the glass first, then slowely start angling the bit so that it's flat and 100% of it is touching the glass. This works great.

I also had a garden hose pouring constantly on the bit/hole for lubrication and it worked great. It also washes away the glass dust.

[FishyFishy!]

I have plenty if I was in edmonton!! haha. I'm sure you can find someone up there that has tonnes of them lying around.

[gregzz4]

If it hasn't already been mentioned, try to drill from the wet side
This way any glass chipping won't be against your bulkhead seal

[Proteus]

I have lots of glass if you want to meet me this weekend ill give you some

[rhody605]

Hey pat I have a bunch of old glass that you can practice on. Just let me know if you need it.

[reef-keeper]

The best guide I found was to drill through a wood like. 1x4 long enough to hold on to while I started the hole in the glass. Then tossed it aside once I was 1/4 way though the glass. Then you'd finish. Sand the rough edges then DONE. Mission accomplished.

[reefwars]

pat , drill on fastest setting . , drill from both sides so not to shell the glass when it breaks through.

put tape over the other side to stop the puck from falling if you have to drill down.

round out your hole by moving the drill around in circles as your drilling, that ways the bit doesnt wedge in the glass hole and the hole ends up just slightly bigger than your bit.

not much water is really needed if the glass is thin , its more for not wearing your diamond bit down , on glass 12mm and over water must be used as the glass gets hot and could split.

when first staring start on an angle like fishy fishy mentioned , then slowly lift your drill up straight , this way the bit doesnt throw you while you start and leave a mark in your panel or chip it.

gl

[2pts]

The way I have done it is to predrill a piece of plywood with a wood bit the same size or slightly larger, clamp that piece of plywood to the front with the hole lined up where you want to drill your new hole. It will give your glass hole saw a guide so your not having it spin off and cracking the glass.

Clamp an undrilled piece of plywood to the back of the glass and dont forget the water running on the hole as your drilling.

That said, after reading this thread, I would probably switch the plywood around part way through, and drill from both sides.

Also you need to find out if that pane of glass is tempered, if it is, all this is a no go.

[e46er]

Put a towel or cardboard or something in the tank so when the piece falls out it doesn't crack the other side of the tank

[paddyob]

Originally Posted by 2pts

The way I have done it is to predrill a piece of plywood with a wood bit the same size or slightly larger, clamp that piece of plywood to the front with the hole lined up where you want to drill your new hole. It will give your glass hole saw a guide so your not having it spin off and cracking the glass.

Clamp an undrilled piece of plywood to the back of the glass and dont forget the water running on the hole as your drilling.

That said, after reading this thread, I would probably switch the plywood around part way through, and drill from both sides.

Also you need to find out if that pane of glass is tempered, if it is, all this is a no go.

If the tank was previously drilled... Is it safe to assume not tempered? Already three holes when I bought it used.

Back drilled.