Enlarging bulkhead hole

[Doug]

Thanks for the great advice guys. I decided that if I need a new bit anyways, to order a 1.75 bit for a new 1in. bulkhead in the back. I also ordered a pair of 1/2 in. bulkheads for the two bottom holes. One will be brought up to a 1 in. stack and drain line as per Steves suggestion. The other to 3/4 in. for my return line.

Sounds good, as long as the second hole drilling goes good. At least this time I will be using a new bit.

[Evilweevil]

Just go to princess auto they drill fine and go with the plywood jig like mono us said go slow and don't use a lot of pressure it will drill fine

[Doug]

Originally Posted by Evilweevil

Just go to princess auto they drill fine and go with the plywood jig like mono us said go slow and don't use a lot of pressure it will drill fine

Thanks. I was thinking, since getting the right bit, instead of drilling new hole in the back I may just try widen the smaller ones, with the wooden jig idea.



BUT


what if bottom is tempered.......

[Maverick00]

+1 on the wooden jig, i made mine out of a 2x4 with a "water inlet" on the top of the hole and "water outlet on the bottom of the hole using a file. You have 5/16" to work with per side which should be plently as long as you go slow and keep the drill as straight as possible clearing the glass "dust" from time to time.

Lots of info on the net on how to test for tempered glass, I thought it had to do with looking at the glass with polarized sunglasses with a smartphone screen illuminated on the other side. I personally wouldnt touch tempered glass.

[Evilweevil]

Does it already have holes in the bottom ? It's probably not tempered if it does but this is just a guess

[Doug]

Yes it does and you,re most likely correct. I have read where they drill the glass first then temper it however. Now that would be my luck.

[Doug]

I think best to error on safe side. I will drill another 1 in. as planned on rear, giving me the 4 holes. Im going to drill it a bit more to the open side of the tank and not closer to the side glass. I will just enlarge my overflow to 1ft. Takes away more tank but I will have a duzer of an over flow and herbie/beanie thing or whatever its called.