Gottcha
12-27-2006, 10:33 AM
Drilling a hole for a bulkhead fitting in acrylic is pretty straightforward, but drilling glass is a little trickier. It can be done by anyone with patience as long as you follow our easy steps. Drilling tanks is an easy way to make some extra cash by drilling tanks for friends. You will need a diamond tipped hole saw, drill, drill ring or modeling clay, sandpaper and saw lubricant.
Make sure the glass you will be drilling is NOT tempered. Tempered glass will shatter on contact.
Figure out where you need the hole and mark with a magic marker.
Using a drill ring or modeling clay, make a small dam about 1" bigger than the hole to be cut, about 1/4" high.
Drill. The easiest way to do this is using a variable speed drillpress (rechargeable drill will work also). This way, you can start slow and then speed up.
Start slowly, allowing the hole saw to scribe the hole that you want without walking all over the glass. Drill slowly like this until the scribe is about 1/16" deep.
Put a few ounces of the lubricant into the ring or the well that you made with the putty. You can now speed up on the drill. DO NOT apply a lot of pressure. Let the saw do the cutting. Rock the drill slightly so the drill does not bind while it cuts.
Keep the saw wet.
When the saw starts to break through the opposite side, back off the pressure and let the saw cut through. Place a piece of cardboard or a towel under the hole so the cut glass does not drop onto the other side glass.
When through drilling, use a small piece of sandpaper to dress the hole to avoid stress cracks. Wash the tank out to remove the lubricant. Remember the saw "dust" you see is actually ground glass.
Follow these steps and you will have no problems. You can drill a hole in a 180 gal tank (5/8" glass) in about 5 minutes.
Make sure the glass you will be drilling is NOT tempered. Tempered glass will shatter on contact.
Figure out where you need the hole and mark with a magic marker.
Using a drill ring or modeling clay, make a small dam about 1" bigger than the hole to be cut, about 1/4" high.
Drill. The easiest way to do this is using a variable speed drillpress (rechargeable drill will work also). This way, you can start slow and then speed up.
Start slowly, allowing the hole saw to scribe the hole that you want without walking all over the glass. Drill slowly like this until the scribe is about 1/16" deep.
Put a few ounces of the lubricant into the ring or the well that you made with the putty. You can now speed up on the drill. DO NOT apply a lot of pressure. Let the saw do the cutting. Rock the drill slightly so the drill does not bind while it cuts.
Keep the saw wet.
When the saw starts to break through the opposite side, back off the pressure and let the saw cut through. Place a piece of cardboard or a towel under the hole so the cut glass does not drop onto the other side glass.
When through drilling, use a small piece of sandpaper to dress the hole to avoid stress cracks. Wash the tank out to remove the lubricant. Remember the saw "dust" you see is actually ground glass.
Follow these steps and you will have no problems. You can drill a hole in a 180 gal tank (5/8" glass) in about 5 minutes.