Drilling a 75

[braydonosu]

I just picked a 75 up off of craigs list and want to get it drilled. I've heard that 75s are tempered on the bottom and the back. I want to have my drain line 3" from the top and 3" from the side. Do you think that it can be done by a pro?

 

[jetskiking]

Best to call the manufacturer or look on their website.

 

[posiden]

How makes the tank?
My 75 isn't temperd, at least the back isn't. I drilled it no problem. That was done after I spoke with the local rep who then talked with the glass people who build the tanks.
I think in the end, if you cant track down who made the tank and or have a glass shop look at the tank with polerized lenses, then it will be a craps shoot. If the later is the option, then drill it on a day you feel lucky. If you aren't going to be the one drilling the tank then get a garentee from the shop.
As for the diemensions you gave, yea it sounds ok but I don't know how big a hole you plan to drill. A rule of thumb is 1 diameter from the edge and 2 diameters apart.
Good Luck

 

[braydonosu]

I don't know the manufacturer because I got it on craigs list and the guy i got it from didn't know either. I can check a glass place, but the only one around here is $25 a hole no guarentee, I guess I can have them take a look at it at least and tell me if it's tempered.

 

[braydonosu]

Oh and I'm going to put a 1 1/4" bulkhead in, so whatever the od is for that I don't remember atm.

 

[posiden]

Well, you are in the same boat I was in. No one around me would give me a gaurentee either. So I drilled it myself. I figured a $12 bit and I could do it as slow as I wanted with no pressure of time spent on a job. Or cockieness for that matter. I am not saying bad things here I just think that way. The glass is always half empty for me.

So a 1 1/4" bulk head, will have different OD's depending on who makes it. I myself did not go with the usual aquarium bulkheads. So my 1 1/4" bulk heads use a larger hole. With that being said, 3" from the top and side doesn't put you in the 1 diameter relm. You are gonna want to go like 3 5/8" from the top and the side to the center of the hole. The rule of thumb I gave you is to the edge of the hole. That is playing it nice and safe IMO. The 3 5/8" is for my 1 1/4" bulkhead fitting. It uses a 2 3/8" hole. The others I am not sure of.
I had a stress program anylize the pressure on the pane of glass on my 75G. I was shocked at how little stress is on the glass at the top of the tank. It does make sense though when you think about it.
Please note; I am not that geekie, I just have access to engineers and cool programs at work.

 

[scsinet]

The question you need to ask yourself is "Is drilling important enough to justify the risk?"
Regardless, if it's a commercially made tank with plastic top and bottom frames, then it was probably only made by one of two manufacturers.
There used to be lots of different manufacturers but mergers and aquisitions have consolidated them to down to basically two players: Aqueon and Marineland. Aqueon (aka Central Garden and Pet) makes AGA and Oceanic tanks. Marineland makes Marineland, Perfecto, and the house brands for many pet stores (PetSmart Top Fin, etc)
So just call them both. Chances are they can each speak for the 75g tanks made by all of their subsidiaries, even before the mergers.
The other thing you can do is look at the glass thicknesses. The entire point of tempering is to reduce the thickness of glass needed, so in theory, if the "back" is tempered and the "front" not, the two slabs of glass will be different thicknesses.
I put those in quotes... because on a rectangle tank... whcih is the back and which is the front anyway?

 

[braydonosu]

The glass is the same thickness all the way around - it's actually pretty thick (I would guess 3/8") but I'm used to my 40 so naturally the 75 would have thicker glass right? I'll look into calling both manufacturers, but yes, drilling is worth the risk. I had a bad experience with a hob overflow when I lost the syphon one day (~ 10 gal of saltwater on the floor is not a good thing)
Posiden - where did you geta diamond tipped bit for $12?

 

[scsinet]

You can get the bits off that famous site where you bid on stuff.

 

[posiden]

I got mine from glass.......holes.

 

[bmkj02]

You can get the bits from glasshole dot com. They also have video on how to do.
Here is another little trick. When you are driving wear sunglasses. Look at your side door glass and you will notice they have like a purple tint like a hologram. Then look at your windshield. Doesnt look the same. Your glass on your car in tempered except for the front windshield. Now look at your tank with the sunglasses and you can tell if its tempered or not. May not work for everyone depending on the sunglass but it does do work.