Glass drill

[ShLiMi333]

Okey so the (old) tropical tank is prepped and ready to be drilled. Here's the dilemma.

I opted for the Herbie overflow which will be situated in the corner of the tank to avoid any unnecessary bends and flow restrictions.

If I'm correct, for a 25mm bulkhead, i will need to drill a 32mm hole?

how close together can i drill 2 holes in the bottom of the corner for overflow?

I will also need to drill a 3rd hole for the return which is also a 25mm.

And, now, the million bucks question.whose got one layng around? Pg glass wont taketherisk of drilling my tank so i need a bit. Please help

 

[Mozzie]

When I drilled my holes I was advised when drilling never drill closer to the edge of your glass than 3 x the thickness of the glass. Take that into mind with your spacing of holes, but I would go with 4 x the thickness of your glass depending on the actual thickness, for example if it was 7 mm I'd give a much larger spacing.

 

[RiaanP]

why not go for 50mm plumbing on the overflow part?

 

[ShLiMi333]

i cant find a big enough drill and the glass companies reckon its on me if the glass crack while they drill it. Sooooo, ill just do it myself. Im installing a herbie overflow so 25mm will be more than enough.

anybody selling or renting or borrowing a 32mm drill?​

 

[chikaboo]

Another bit of advise ... Actually the one line we always hearing in thus hobby ... take it slow .. very slow ... also take like a 1 litre plastic cool drink bottle and fill with cold water and and poke a few small holes in cap and constantly squirt on drill bit while drilling ... done mine like that in 50mm and never had a drama ... be patient ... but don't be lax with the pressure either ... to much play on the drill and you asking for trouble ... so to recap ... slow but firm ànd constant water flowing ...

 

[ShLiMi333]

Thanx Chicaboo
I bought a 10ml diamond drill ( its the only size i could find) and i just started drilling a million holes in some leftover glass i had from the sump build. I know its not 32mm but ill get there.

 

[Mozzie]

Make yourself a template aswell, the diamond drill bits don't have a guide so a template is very important or the bit will run all over the glass and scratch. The key is light pressure, let the bit do the work and plenty water. Get yourself some prestic and once you have the start of a hole, remove the template and build a damn with the prestic, fill with water and continue drilling slow. It took me 5min to drill one hole through 10mm glass. Another important thing is to make sure you are drilling level or the exit hole will burst. Check out YouTube there is plenty of demos and the. Most hardwares will stock the diamond drill bit but they are costly. Good luck

 

[ShLiMi333]

Thanx, I'm geared up. I'm going to use my cordless screwdriver for the job as i can run it on much lower constant RPM. Thanx for the advice, I will be taking the plunge today or tuesday depending on time at office.