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Jac@stafford.net
22-Apr-2016, 10:35
Recommendations for a supplier of quality drill bits for glass?

I'm re-purposing some old, large filters and would like to drill some holes in them. I practiced on some scrap glass using 'glass & ceramic' drill bits that wore out almost immediately. I used drilling lube (Mobil 1), with no improvement over some thick conventional lube.

The largest filters are .53" thick (and 8.5" diameter).

Thanks if you can help.
Jac

Peter De Smidt
22-Apr-2016, 10:54
What size holes?

Jac@stafford.net
22-Apr-2016, 11:12
What size holes?

oops! Yes, that is important. Largest hole 12.6mm (1/2" nominal), and 6.4mm (1/4" nominal).

Thanks for the nudge.

Peter De Smidt
22-Apr-2016, 11:32
I've some experience drilling holes in aquariums. For that, I used diamond bits. They were for bigger holes, but I don't see why smaller ones shouldn't also be ok. Here's a link to one: http://www.amazon.com/gp/product/B000VR7E60/ref=pd_lpo_sbs_dp_ss_3?pf_rd_p=1944687502&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B000VR7E6U&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=135SHW320W4Y6ZCPDBWM

Drew Wiley
22-Apr-2016, 12:14
They're basically little hole saws with diamond grit attached. Use them with water as a lubricant and at a relatively low (slow) RPM. Take you time, and don't expect an exact hole diameter afterwards.

Jac@stafford.net
22-Apr-2016, 14:04
I've some experience drilling holes in aquariums. For that, I used diamond bits. They were for bigger holes, but I don't see why smaller ones shouldn't also be ok. Here's a link to one: http://www.amazon.com/gp/product/B000VR7E60/ref=pd_lpo_sbs_dp_ss_3?pf_rd_p=1944687502&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B000VR7E6U&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=135SHW320W4Y6ZCPDBWM

That is helpful. Thank you. I must admit ignorance, but I do not know how deep a hole I can cut with the Dewalt bit. Will it do 1/2"? Should I just go with the flow and try it? These pieces of glass are as rare as unicorn horns. Thanks for your time.
.

Peter De Smidt
22-Apr-2016, 14:19
I've drilled through 1/2" thick aquarium glass with similar bits. I wouldn't be stuck on the Dewalt. I picked it mainly because it was the same type of bit I used, and it popped up quickly on a search. Note that with thick aquarium glass I never had a problem, but if you're using thinner glass, you'd want to come up with a support system to minimize the chance of breakage.

Michael Rosenberg
22-Apr-2016, 14:59
I have done this for an enlarger pin registration system to match my Condit punch. Use diamond drill bits, and get a couple of them because when they overheat they will be unusable. I drilled small holes, and used a dremel in a drill press so I could control the drilling and not risk overheating . Overheating will not only ruin the bit but cause the glass to crack. I had to cool the glass and drill bit with ice water, so I made a reservoir out of plywood and then sealed it with polyurethane. I then could put the glass on the bottom and flood it with water and ice. For precision I got a brass kick plate from the hardware store and cut a strip the right size, then drilled the holes at the right places, placed it over the glass, and used the holes to align the drill bits. If I had not done this there was no way to be consistent and precise. Every 2-3 pieces of glass I had to replace the bits as they would dull, and I was using 3 mm thick glass!

Mike

Jac@stafford.net
22-Apr-2016, 15:06
Every 2-3 pieces of glass I had to replace the bits as they would dull, and I was using 3 mm thick glass!

Thank you for the caution, Mike. My glass is tempered, colored military stuff of 1/2 inch thick. A daunting project considering my ignorance.


I have done this for an enlarger pin registration system to match my Condit punch.

Wow! I have a Condit punch and haven't figured out how I can use it. My objectives are first, a true unsharp mask (not as inadequately describe on the home page here), and to use contrast masks. Separate thread maybe?
.

Peter De Smidt
22-Apr-2016, 15:19
It sounds like Michael was using a fast rpm. I used cheap no-name diamond hole saws to drill 2" holes in 1/2" thick glass for aquariums. People would come by because I knew how to do it, and so I did quite a few. I could get 10 tanks easy out of one bit. Don't be in a hurry, and keep the glass and bit cooled with water.

Dan Fromm
22-Apr-2016, 16:16
jac, I've drilled many aquariums with a diamond tipped hole saw. Plain glass bottoms. Nowadays most aquariums are made with tempered glass bottoms and the manufacturers warn that they will fracture if drilled. Think of what happens when the tail of a Prinz Eugen drop is broken or even just scratched.

If you must have holes in your rare filters, please try to find a common version that you can try drilling first.

Jac@stafford.net
22-Apr-2016, 16:26
If you must have holes in your rare filters, please try to find a common version that you can try drilling first.

Rare? I did not consider that. I will investigate, but I doubt anyone wants these monsters. I will find out. I do have some 144mm filters, too. Man, I should do an inventory.

Thank you, Dan. I will also look for some 1/2" glass to test.

Struan Gray
23-Apr-2016, 00:22
If you want an accurate, clean hole, laser drilling beats all other methods. Available as small-scale contract work, but it's a bit like metal workshop stuff – things are easier if you know someone with the kit and some spare time.

I used to know some crazy Estonians who could put clean holes in any insulator. They would put M2 screw threads in single-crystal sapphire. All done with a suitable form, fine-grain carborundum or diamond slurry, and a *lot* of patience.

Jac@stafford.net
23-Apr-2016, 05:54
[...] All done with a suitable form, fine-grain carborundum or diamond slurry [...]

I'm imagining an impish creature sitting cross-legged on a dirt floor with a magic mortar grinding diamonds and spit.

Struan Gray
23-Apr-2016, 06:34
I'm imagining an impish creature sitting cross-legged on a dirt floor with a magic mortar grinding diamonds and spit.

That's pretty much how they marketed themselves. Like Swiss elves, but cheaper. Reality was cleanrooms and stainless steel.

Michael Rosenberg
23-Apr-2016, 09:26
Peter,

The larger the hole/drill bit the longer it would last because of heat dissipation and the bit will last longer; that being said, the more precise you need to be may require replacing the bit more often.

Regarding speeds, I was using a dremel mounted in a dremel drill press to make sure my holes were straight, set a depth adjustment, and prevent wobble. With the dremel I could carefully control speed, and so was not going too fast. In fact, I would drill for 2o sec.s and then back off for a few sec.s to avoid heat build up. The drill bits were 1.2-1.5 mm diameter.

If you are drilling tempered glass remember that it is extremely hard, so cooling and going slow will be important. I suggest getting some scraps from a glass shop to practice on.

Mike

Michael Rosenberg
23-Apr-2016, 09:29
Jac,

PM me and I'll send you my method for making unsharp masks. I think I also have a copy of Howard Bond's PT article.

Mike

Peter De Smidt
23-Apr-2016, 09:31
The larger the hole/drill bit the longer it would last because of heat dissipation and the bit will last longer; that being said, the more precise you need to be may require replacing the bit more often.



Fair enough, Mike.

Richard Wasserman
23-Apr-2016, 13:02
I've drilled probably thousands of holes in various types and thicknesses of glass. I always used a diamond core drill with water as a lubricant and to cool the material. It's probably a bit over what you are looking to spend Jac, but this look at core drills and adapters on this page to see what I'm referring to—

http://www.mcmaster.com/#diamond-drill-bits/=123zm3t

Harold_4074
1-May-2016, 08:10
I don't see that anyone has mentioned the exit chipping problem.

This isn't too bad with diamond core drills, but is terrible with spade-type bits. The easy solution is to attach a thick piece of scrap glass to the exit side (using a thin adhesive which will stand up to the cutting fluid but be cleanly removable later) so that the exit edge is fully supported. If your setup isn't sufficiently rigid to prevent "walking" at the start, sticking on a piece of sacrificial glass on the entry side can help with that.

My preferred adhesive has always been beeswax, using soluble oil in water for cooling.