Cutting A Glass Disk?

[Chipper5783]

How to make a replacment glass cover for this lamp? I'd like to replace the glass cover on this lamp (3/16" thick x 4-5/16" diameter). I've made a few straight cuts in glass (even that was challenging to get nice cuts). How do you cut a circle?



I duct tapped the other side to try to keep it stort of intact (so as to measure it, and minimize the clean up).

 

[ogberi]

Compass with a suction cup center. Scribe the circle, then scribe 4-5 lines going off at right angles to the circle. Hit it with a bit of heat, then use smooth jawed pliers to break it along the scores. It's hard to explain, but you angle the pliers so they aren't clamping evenly, support the glass on the table, and just barely squeeze. I usually put the edge or corner of the plier jaws on the scribed line, on the opposite side of the scribe, and the corner or edge of the top jaws on the scrap side of the scribe. A gentle squeeze causes a crack to run along the scribe. Then just chase the crack around from there. Glass cutting like that takes practice, so do not get discouraged if the first half dozen attempts end badly. I reccommend scribing a half dozen circles first, so you are still in break-along-the-score mode if you bust one and have to start over. Just my $.02

 

[turnitupper]

I have cut circles using an ordinary oil filled glass cutter and a template cut undersize to allow for the thickness of the cutter. Then I cut lines at a tangent to the circle and snapped off to remove most of the waste and finished on a belt sander. Took about 8 tries for a 6" disc. A much better way is http://glassshop.com.au/cutting-glass-circles/ , which is the way my glazier friend does it to great success (99/100), smart arse. Just make sure your glass is very clean and your cutters are in good condition. Using a cheap cutter or one that has been sitting rusting in the shed is almost certain to cause grief. A decent circle cutter and oil filled cutter set can be had in OZ for around $A25, that's approx. $US 1.30 at the current exchange rate
Good luck to you and remember,in glass cutting, practice makes perfect, and blood.
John.

 

[kingmt01]

I'd buy it too. Just found two for $10 USD on eBay that are 110mm. That's kinda a odd size I haven't seen in a while. It used to be common iirc.

 

[f350ca]

A local glass shop would be able to cut one for you David. I had them cut circles for dump bailers when I worked in the oil field. They have wet belt sanders to smooth the edges. The one you have appears to be tempered by the break pattern.

 

[Ebel440]

Iv never tried a big one. But i did a small hole this way. You can make a hole saw from copper tube. Then build a dam around the glass a little bigger then your circle. Put some powdered abrasive in with a little water or oil and drill getting the abrasive to do the cutting.

 

[Bill Gruby]

Go to you local window shop od hardware store and have them cut it for you. If you have never cut one before it will be sheer luck if you get one in the first few tries. It's your choice, we can only guide you.

"Billy G"

 

[wawoodman]

I would say "no" to the idea of scoring extras in advance. My experience has been that glass will "heal" and that you get the best results from a quick, LIGHT score (you should hear a hiss, not a crunch) and snap immediately.

Or, you could use scissors...

 

[mhooper]

"Victor V" has a recent utube video on cutting glass circles.
I think he has done more than one because he makes it look easy.

mhooper

 

[jim18655]

You might need heat resistant glass for that lamp.It looks like a halogen bulb.