Cutting small glass circles

[nickel-city-fab]

I need to cut a few 2 7/16" diameter glass circles. Thickness is approximately 2mm. The circle cutter I have won't go that small and can't be modified. Does anyone have actual experience cutting glass circles that small? I've seen a couple advertised on Amazon and eBay but I'm looking for someone that has a cutter that goes that small. What are you using IF you've cut glass circles this size or smaller?

-JW:

In Practical Blacksmithing (1880) a reader describes a process for drilling holes of any size in glass, using a copper tube with some abrasive powder and olive oil. Some cheap (eBay) diamond lapping slurry would be perfect. Make the ID of the tube the diameter you need for your disc, maybe a piece of water pipe? Spin it with a drill.

[JoeLee]

In Practical Blacksmithing (1880) a reader describes a process for drilling holes of any size in glass, using a copper tube with some abrasive powder and olive oil. Some cheap (eBay) diamond lapping slurry would be perfect. Make the ID of the tube the diameter you need for your disc, maybe a piece of water pipe? Spin it with a drill.

Like a core drill ! Still have to watch the heat, speed and break through. I read about that somewhere but forgot about it.

JL.............

[Georgineer]

I started a thread on the same topic on the Model Engineer forum a while ago, and there was some useful information in that:

https://www.model-engineer.co.uk/forums/postings.asp?th=169122

I have to confess that I haven't yet tried any of the techniques suggested, so can't comment on how effective any of them is.

George B.

[alanganes]

That is going to time consuming as well as messy.
I had to drill some 1/8" holes in 1/4" plate glass for handles, 16 in all. It was a diamond abrasive type bit. Had to keep dripping water on a and keep it cool. Did it in my drill press, had to go real slow, as slow as the DP would go. Probably about a half hour per hole. And yes, had to be real careful at the breakout point or the opposite side would chip out. Wouldn't want to go through taht again. Sounds like that hand cutter listed on ebay would be the way to go for your circles.

I've made replacement glass covers for things like levels. Easy to cut square or rectangular pieces. The time consuming part was rounding the corners on a belt sander. Again, have to watch the heat.

JL...............

Where I work we do stuff like this by the boatload.

No need to run the bit at low speed, but you do have to keep things cool as you noted. We use water feed on the bit, but it works just as well to do as was mentioned above and build a dam of clay around the bit and fill it with water so you can run the edge submerged. The bits (either diamond or a brass tube with abrasive slurry) run at maybe 500 or 600 rpm and you just peck drill with them. Don't push too hard and you can cut a nice hole through a 1/4 glass plate in maybe 45 seconds.

I have drilled holes in glass plates, ceramic tiles, and grinding wheels like this on a drill press as well as on a milling machine. Pretty much the same process. The only trick are to keep things cool and do not apply heavy cutting pressure. Just let the abrasive do all the work for you. I was amazed how easy this actually is the first time I tried it. I practiced on a few scrap pieces to get a feel for how it goes, but it was not really difficult.

[boslab]

I’d use a glass cutter slightly oversize and grind with a diamond lap, aka the cheap Chinese ones, use a snapping pliers, bit of judicious tapping should fracture it, you can do the snapping in a bowl of water to damp it a bit,
mark

[Smokedaddy]

I apologize for not being clearer. I have a circle cutter that works great, but it barely cuts 2 1/2" circles. The glass is for a Leica Wild Heerbrugg microscope stage. I only need to cut two, but I have friends that would like some as well. All (note the all) my machining equipment is in storage in Phoenix, Az, and I moved to Bigfork, Montana. Due to the crazy prices of lumber, I can't build my shop right now. Therefore, no tooling, not even a drill press. Since I've been coming here for many years, I thought I would ask if someone had a suggestion. I saw this device on Youtube, but the circles look like a POS. Below is a 3 1/8" circle that came out sweet. I just need to figure out how to cut smaller ones with the same quality.

[john hobdeclipe]

This is as simple as it sounds. You pour melted wax on a square of glass and then place another on top of it.Pour wax on that one and add another, an so on. Squeeze them all together while the wax is still hot and then let the pile cool. It is typically done with the parts sitting on a hot plate. A bit messy, but quite easy and effective. This leaves a very thin layer of wax between the pieces that acts like glue to hold the stack together. Warm them up to separate. I expect there are a bunch of other specialty waxes for this but typically it's beeswax or a 50-50 mix of beeswax and rosin.

Thanks!

I recently did a project that required discs of stained glass, stuck to an aluminum face plate, edges ground true then faces decorated with engraving. I finally settled on WeldWood contact cement, but using MEK to release the cement was not fun at all.

So I'll try beeswax next time. What do you use to wash off the wax residue? (please don't say MEK!)

[reggie_obe]

Maybe a more realistic question would be, who can cut four circles of glass for me?

[Stepside]

SD

Check your mail I sent you a contact.

Pete

[alanganes]

Thanks!

I recently did a project that required discs of stained glass, stuck to an aluminum face plate, edges ground true then faces decorated with engraving. I finally settled on WeldWood contact cement, but using MEK to release the cement was not fun at all.

So I'll try beeswax next time. What do you use to wash off the wax residue? (please don't say MEK!)

I don't recall what they dissolve it with, some stuff in an ultrasonic cleaner. I think really hot soapy water followed by a wipe down with alcohol may work just as well. I will ask on Monday if i remember, we have guys that are actual experts on such stuff around there.

[Bented]

That would be the way to go but how many of us have such equipment ?

JL...............

You likely do not, however if 100 parts are required then send the job to a shop that does such work daily.
The OP never lists how many parts are required 1 ,10. 100 or 1000.

[JoeLee]

You likely do not, however if 100 parts are required then send the job to a shop that does such work daily.
The OP never lists how many parts are required 1 ,10. 100 or 1000.

I would also imagine that any place that has the equipment also has a minimum part or dollar amount.

JL...............

[Smokedaddy]

I only need a couple but would love to have a couple of dozen since they get broken sometimes.

-JW:

[genea]

I don't recall what they dissolve it with, some stuff in an ultrasonic cleaner. I think really hot soapy water followed by a wipe down with alcohol may work just as well. I will ask on Monday if i remember, we have guys that are actual experts on such stuff around there.

Beeswax will dissolve in naptha.

[epicfail48]

Lot of complication for something that should be relatively simple... Get a suction cup, a set of dividers, and a normal glass scriber. Tape the scribe to the dividers, set the dividers to the size of the disc you want, stick the suction cup in the center of your glass, set the non-cutter leg of the divider on top of the suction cup, run it in a circle. Snap glass as normal

All you need is some way to run a scriber in a circle, no need to get fancy with drill presses and core drills and waterjets