Water – Making a small drain/vent/hole in a glass box

drainagedrillglassmaterialswater

I've got a glass box that measures 900mm x 450mm x 450mm.

The width of the glass is about 6mm thick.

If I drill, cut, or grind a small hole in/through one of the faces; will it significantly affect the structural integrity of that piece of glass?

I'm concerned it might become prone to flexing, and cracking; if I pick it up to move (or transport) it, for instance.

Is there some kind of ratio, or formula that I can use to determine a relatively safe size, and adjacent edge distance for an aperture?

If you're wondering: It's basically a small indoor display garden / vivarium type situation, which needs at least a single outlet point through which gravity can be allowed to drain the excess fluids from the soil.

glass box schematic diagram

Best Answer

While I cannot cite any specific sources for this, I'm going to posit the following answer:

Yes, structural integrity will be affected, but not enough to be concerned about.

The box you describe is not suitable for carrying any kind of load anyway, and as you state above it's for display purposes. Drilling a tiny hole will not cause any cracking - in fact it's a technique used in windshields (particularly aviation windshields used in small planes) to STOP cracks from continuing to spread. (Small hole drilled right at the leading edge of an expanding crack relieves the stresses in a sound manner)

Granted aviation glass is different than what you've got but still - I think you're fine. I'm curious though why drill a hole in it? That will have a tendency to trap moisture.