Drilling holes in sinks

Liam · Post by **Liam** » Sat Oct 25, 2003 9:53 pm

The neck on my drill press isn't long enough to drill holes in sinks. Has anyone ever used one of these
http://www.crlaurence.com/ProductPages/ ... 49&Origin=
1300 rpm
or

http://www.crlaurence.com/ProductPages/ ... 70&Origin=
2800 rpm, hmm seems kinda fast to me,
or is there another alternative?
Thanks
Liam

Ron Coleman · Post by **Ron Coleman** » Sat Oct 25, 2003 9:59 pm

Liam

Bert uses one like the first one to do sinks. He had it a WGW and did a demo. He can fill you in on all the details. Looks like it's the best way to go.

Ron

Ron Coleman · Post by **Ron Coleman** » Sat Oct 25, 2003 10:09 pm

Just found the link to the hole drilling pictures.

Thanks to Lisa W we have a photo record.

http://f1.pg.photos.yahoo.com/ph/girlbe ... %26.view=t

Toward the bottom of the page.

Ron

Liam · Post by **Liam** » Sun Oct 26, 2003 8:42 am

that looks much bigger than I imagined it, and looks heavy too.
I also thought that a core bit was what would be used.

Liam

Tom White · Post by **Tom White** » Sun Oct 26, 2003 9:05 am

Liam, I have the radial drill press from Harbor Freight Tools and have used it with a tungsten carbide core drill to drill the hole in a slumped sink about 3/4" thick. It costs less than $200 and can be used as a regular drill press for other drilling operations. It may be slightly under powered with only 1/3 hp motor but that can be replaced with a larger one if needed. Here is direct link
http://www.harborfreight.com/cpi/ctaf/D ... mber=44846

Best wishes,
Tom in Texas

Bert Weiss · Post by **Bert Weiss** » Sun Oct 26, 2003 9:46 am

The Tripod drill is a very useful glass drill, especially for we who are working with not so flat glass. The newest glass drills come with suction cup bases. The cups wouldn't work on textured or slumped glass. Mine has a very heavy duty motor.

I saw the ultimate sink drill at a glass shop in NC. It was a very deep throated drill press with a water filled base. Water is pumped through the core drill bits all during the drilling. With this rig you could drill through the bowl from the inside. Actually the real ultimate glass drill, drills from both sides toward the middle.

Hand drilling glass is extremely difficult as you can't see where the hole is once the water clouds up with glass dust. Core bits, which are very expensive, wear out very fast when used in a hand drill.

We ran in to killer drilling when drilling "small" diameter sink bowls. The glass broke as the bit exited the bowl on the inside surface. The solution would be to flatten out the bowl shape. I have never had this happen on larger bowls.

Marty · Post by **Marty** » Sun Oct 26, 2003 10:27 am

We just sandblasted the hole- got a metal washer (with the same inside diam. as the hole) for a mask and blasted a narrow ring; the plug dropped out. Had to keep the angle of the blast consistent. It took about 10 to 15 minutes to go through 3/4" BE.

Tom White · Post by **Tom White** » Sun Oct 26, 2003 12:05 pm

My radial drill press will drill to the center of a 34" workpiece. When I drilled the glass sink bowl I had flattened the bottom of the bowl on a diamond lap so it was flat and parallel to the rim. I sat a plastic container on the drill press table, placed a 3/4" piece of plywood in the container and placed the sink on that. I positioned the sink so that the drill was centered in the bowl and added water in the plastic container to just above the 3/4" plywood and about 1" inside the bowl. I drilled with a Remgrit tungsten carbide core drill which has a pilot drill in the center. The water in the bowl became cloudy very quickly but was not a problem with the drill press to keep the core drill aligned. I drilled with a manual up and down motion to clear the cuttings from the groove being cut by the core drill. I could feel when the pilot drill cleared the bottom of the glass into the plywood below the bowl. I slowed the drilling by reducing the pressure on the core drill and finished the hole with very minimum chipping on the bottom of the bowl. It would have been possible to stop when the pilot drill exited the glass and turn the bowl over, bottom up, and drill the rest of the hole from the bottom to have no chipping but this seemed like a lot of effort for very little gain.

Best wishes,
Tom in Texas

charlie holden · Post by **charlie holden** » Sun Oct 26, 2003 2:21 pm

You can get a waterfeed drill bit attachment which allows you to hook up a pump and run water through the center of your core bit as you drill. They are expensive but save a lot of set up hassle if you're doing a lot of drilling.

http://www.granquartz.com/waterfed.htm

dee · Post by **dee** » Tue Oct 28, 2003 10:16 am

Marty wrote:We just sandblasted the hole- got a metal washer (with the same inside diam. as the hole) for a mask and blasted a narrow ring; the plug dropped out. Had to keep the angle of the blast consistent. It took about 10 to 15 minutes to go through 3/4" BE.

marty, what type/abrasiveness of grit are you using to do that? and are you using a pressure pot or siphon feed system? and what psi?

D

Tony Serviente · Post by **Tony Serviente** » Tue Oct 28, 2003 11:13 am

Posted this before, but I went through a 1" sink with my Milwaukee 1/2" drill and a 2" core bit. Started from the outside with a clay dam, got about 8/10ths of the way through, then flipped it over and put water in the basin, and met the first hole. Eliminated exit hole chipping. Biggest problem was keeping it true and starting the drill from a dead stop. Those 1/2" drills have quite a bit of torque, and if it grabs the glass it either wants to break your wrist or the glass. Fortunately I avoided both. Marty-out of curiosity, doesn't the washer get really hot?

Marty · Post by **Marty** » Tue Oct 28, 2003 8:04 pm

Tony- the washer is more of a guide, we kept the main part of the stream just inside it. Duct tape kept it on and if it did get hot, it wasn't enough to do any damage.

Dee- 180 grit Silicon carbide in a pressure pot at about 35 lbs.

Bill Grix · Post by **Bill Grix** » Tue Oct 28, 2003 10:27 pm

Hi
I use a drill like the one shown in the picture. what I do is take off the legs and put two boards across the top of your sink. set the drill on the boards, line up your core bit to the location of your hole. put a few inches of water in the sink and drill

Bill

Cher · Post by **Cher** » Wed Oct 29, 2003 8:52 pm

When I was at Corning, one of the attendees there gave me one and only one tip for making a sink. "Get it die cut" was all she'd tell me about the many she's made. So, what is that? is that what anyone has described here????
Still baffled
Yo

Marty · Post by **Marty** » Wed Oct 29, 2003 11:23 pm

Baffles me too.
Was this a coldworking class running at the same time as B&A in August?

Die cutting is, as far as I know, punching out a shaped hole in a maleable material with a die that's harder than that material.

What was she thinking?

Cher · Post by **Cher** » Thu Oct 30, 2003 12:36 am

hi Marty
Class was hot glass horizons, discussion was during dinner. She said it had to be scored first, then (I swear she said die cut). Could i have a faulty memory and she said lazer? What was she thinking/saying?? I think I will have to let the guys at the local glass shop take care of it for me for the first dozen sinks. I sure can't imagine scoring a fused slumped piece.

DanB · Post by **DanB** » Fri Oct 31, 2003 3:29 pm

I needed a way to drill large dia glass bowls and did not want to buy an enormous drill press with a giant throat, so I purchased an inexpensive small drill press for $100, reveresed the support stand column so that it extended up through the pulley box on top, and then mounted the drill press to the ceiling in my workshop. It looks like it is mounted upside down, but the drill head and pulleys are all normal orientation. Now I basically have a drill press with an infinite throat and can do any diameter piece.

Liam · Post by **Liam** » Fri Oct 31, 2003 3:56 pm

Now why didn't I think of that. Very cool, thanks

Liam

Tony Serviente · Post by **Tony Serviente** » Fri Oct 31, 2003 4:07 pm

Dan should get the "thinking outside the box award". I would love to have done that, but my ceilings are 14" high! Oh well. What I might do is to weld up a rolling frame with just a drill press head in the center. Like a little portable ceiling.

Tony Serviente · Post by **Tony Serviente** » Fri Oct 31, 2003 5:19 pm

Typing fast and loose, and it shows. Should have been 14'.