It is not enough to buy diamond tips to make a hole in the glass, the work in question needs some attention that cannot be ignored. First point, which all drilling works have in common : clean the surface well, fix it so as to avoid unnecessary movements and work safely. If the glass breaks you must be in a position not to injure yourself with splinters and shards. That said, you need to fit the bit into the chuck and let the drill warm up a bit.
Bring the tip closer to the glass and start creating a dip. The calm will help you not to slip the tip on the glass, but you can use a little adhesive tape on the precise point where you want to drill: in this way you give the right adherence to the tip. Then continue with the drilling proceeding with reduced speed and minimum pressure. The watchword is prudence. Glass is not a good thermal conductor, it does not disperse heat well.
This means that fast drilling can cause not only breakage, but also burns . So take your time and decrease the speed / pressure when you are about to complete the hole – this is one of the most delicate moments. The risk of breaking the glass is just around the corner, don’t accelerate right now that you’re almost done.
ou can use water to cool the tip and the material, but be careful: you are in contact with an electric tool. Keep the tip perpendicular to the glass, especially in the final part of the hole. In this case, you don’t just risk making a bad hole: you can shatter the object you want to pierce. In these cases, the use of a drill press can be decisive because it allows you to manage the position of the tip with extreme care. Although, with a fragile material like glass, it can be convenient to manage the pressure on the tip yourself.
Without a drill. In some cases we speak of piercing the glass with the needle, in others of heating the glass and playing with the temperature change. My idea? Work safely, without improvising. Making a hole in the glass for the air conditioner or for other maintenance works does not admit mistakes: a few euros and you buy a perfect diamond tip to drill the glass without risk.