drilling glass question?

[bucky56477]

Right now my tank is drilled for a 1" bulkhead (1 3/4 " hole), I want to enlarge this hole to accomidate a 1 1/2" bulkhead (2 3/8") hole. Any advice on this, should I just use a diamond hole saw, or is there a better way? thanks for the help.

[superedge88]

Diamond hole saw should do the trick just fine.

[uchiha]

this is exactly what i had to go through on my last tank (enlarging the hole). just do it SLOWLY and keep the glass cooled ... good luck :)

[newnano]

a good way to do this is to drill a hole in a scrap piece of plexiglass as a guide. then tape the plexiglass guide where you want your hole. as you are drilling have someone pour a little bit of water around the bit every once in a while. that will keep it cool. go slow. when it is about to go through back off on the pressure almost like you are pulling it away. it will help avoid making those pock marks that will extend beyond the bulkhead gasket and cause leaks

[Norboo]

Is that tempered glass? In general, bottom of the tanks are tempered.

[Norboo]

Curiosity got the better of me. Why do you need such a big bulkhead? For better drainage for the stand pipe?

[bucky56477]

Yea, right now I only have 1 overflow in the center of my tank. I am trying to decide if I want to make that hole bigger, or if I want to take that overflow out and put 2 new ones in the corners. If I put the two new ones in, does anyone have any ideas about plugging the center hole? Would it be better to leave the bulkhead in and seal both sides of it, or would it be better to take the bulkhead out and silicone a piece of glass over the hole?

[teh215]

<a href=showthread.php?s=&postid=8497380#post8497380 target=_blank>Originally posted</a> by bucky56477
Would it be better to leave the bulkhead in and seal both sides of it, or would it be better to take the bulkhead out and silicone a piece of glass over the hole?

If it's not leaking, I wouldn't mess with it. My 2¢

[Norboo]

Been working on how to improve drainage rate myself. This is what I came up with.

Use male adapter 1 1/2" to 1 1/4" as a bulkhead. Use one side threaded coupling to secure the bulkhead from under the tank. That would leave you with 1 1/4” drain. If you wish to use 1 1/2" stand pipe, you don’t need a reducer. If you plan on using a reducer, make sure you use slip kind not threaded. Threaded has smaller diameter on the inside.

Last, file/sand all the fittings/pipes that meets the water head on to reduce friction.

Example:
Example:

water flow direction >>>>>>>>>http://img.photobucket.com/albums/v65/Norboo/fittings_slip_x_slip_bushings.jpg


This should help with your drainage.

Use sch 26 pipes. Hope this helps…better than trying to drill and seal.

DIY Bulkhead (http://archive.reefcentral.com/forums/showthread.php?s=&threadid=967098)