JamesOzment1 wrote:I know when steel aloys are hardened in particular firearms knives industrial parts ect... that they need to be annealed befor machining/drilling/engraving.so perhaps instead ofvresearching how to drill tempered glass try researching how to anneal it .
Then the question is will the annealed glass contain the strength needed to subdue the spring tension of the relockers? If I am not mistaken I have seen my grandfather bore large diameter holes up to 2" in what appeared to be tempered glas on a coffee table with diamond holesaw bits and a water/soap mixture.
A large portion of tempered glass is produced by taking annealed glass, heating it above its annealing point and cooling it rapidly so as to 'freeze' the outer surface of the glass while allowing the inner core to remain soft for a longer period of time. Even after cooling the glass is a balance of forces, with the crust pulling inward while the core pushes outward.
With tempered glass, you could attempt to re-anneal; heating the sheet above roughly 900 degrees F, holding it at temp, and gently stepping it down over a lengthy period determined by piece thickness to below roughly 700 degrees F. Temperature must remain consistent throughout the sheet, or else you'll introduce stress cords into the annealed piece and you're back to a similar issue to the one you started with.
In the context of a glass relocker, this would prove highly impractical. The consistency of heat required is simply not going to be achieved within a safe (I cannot stress enough how consistent the heat has to be throughout the glass). Even if you were somehow able to heat consistently, once the glass is heated above the annealing range, it would soften to the point that the relockers would fire.
Not trying to be discouraging here. By all means, if you can find a way to do it, go nuts; I'd love to be proven wrong on this, because it would be an awesome feat. I'm just relaying what many years of glasswork taught me.
Posted: Wed Feb 04, 2015 3:09 am
