Drilling return for 1/2” glass

Rdthedo · 10/20/2018, 01:47 AM

Hey all,

This is my first time actually doing a full build after having sold my AIO biocube 29gal. The project is an Aquamaxx 64.2gal (low iron, non-tempered, 1/2” glass), with a 45gal sump. I’ll be drilling two 62mm holes for the 1.5” bulkheads into Reef Savvy’s Ghost Overflow, and then drilling 45mm holes for return bulkhead.

I am not really finding clear info as to how close to the top I can get safely without cracking. Some places are saying half the diameter of the hole, some are saying no closer than 1”. I’m trying to maximize height in an effort to drill holes to stop siphon into the return. I’ll also be plumbing a check, but I really want that to only be an extra fail-safe measure.

Does anyone have input as to how close to the top is safe in 1/2” glass?

Rdthedo · 10/20/2018, 02:09 AM

So I just found two equations that are contradicting each other, to further complicate the original post: one says 1-1.5x the glass thickness, one says 1-1.5x the hole diameter.

hearttx · 10/20/2018, 04:16 AM

I read you should use the hole size distance you mentioned.

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Gorgok · 10/20/2018, 04:42 AM

The 1.5 or 1x confusion comes from holes needing to be spaced about 1 diameter apart from edge to edge. If you already have one hole its simpler to measure 1.5 diameters away and that is the center of the next one. They are still only 1 diameter away from each other though.

Rdthedo · 10/20/2018, 06:38 AM

So 1-1.5x the diameter of the hole being drilled from the edge of the glass then, correct?

hearttx · 10/20/2018, 06:40 AM

That's what I did for my holes in the bottom of the tank. Mine was 1/2 inch glass as well.

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10/20/2018, 01:47 AM	#1
Rdthedo Registered Member Join Date: Aug 2015 Posts: 12	Drilling return for 1/2” glass Hey all, This is my first time actually doing a full build after having sold my AIO biocube 29gal. The project is an Aquamaxx 64.2gal (low iron, non-tempered, 1/2” glass), with a 45gal sump. I’ll be drilling two 62mm holes for the 1.5” bulkheads into Reef Savvy’s Ghost Overflow, and then drilling 45mm holes for return bulkhead. I am not really finding clear info as to how close to the top I can get safely without cracking. Some places are saying half the diameter of the hole, some are saying no closer than 1”. I’m trying to maximize height in an effort to drill holes to stop siphon into the return. I’ll also be plumbing a check, but I really want that to only be an extra fail-safe measure. Does anyone have input as to how close to the top is safe in 1/2” glass?

10/20/2018, 02:09 AM	#2
Rdthedo Registered Member Join Date: Aug 2015 Posts: 12	So I just found two equations that are contradicting each other, to further complicate the original post: one says 1-1.5x the glass thickness, one says 1-1.5x the hole diameter.

10/20/2018, 04:16 AM	#3
hearttx Registered Member Join Date: Sep 2016 Posts: 75	I read you should use the hole size distance you mentioned. Sent from my SM-G930W8 using Tapatalk

10/20/2018, 04:42 AM	#4
Gorgok Registered Member Join Date: Feb 2011 Location: Cypress, Texas Posts: 1,904	The 1.5 or 1x confusion comes from holes needing to be spaced about 1 diameter apart from edge to edge. If you already have one hole its simpler to measure 1.5 diameters away and that is the center of the next one. They are still only 1 diameter away from each other though.

10/20/2018, 06:38 AM	#5
Rdthedo Registered Member Join Date: Aug 2015 Posts: 12	So 1-1.5x the diameter of the hole being drilled from the edge of the glass then, correct?

10/20/2018, 06:40 AM	#6
hearttx Registered Member Join Date: Sep 2016 Posts: 75	That's what I did for my holes in the bottom of the tank. Mine was 1/2 inch glass as well. Sent from my SM-G930W8 using Tapatalk