I was recently working on a sandcarving project which required me to cut a thick glass mirror of about 1/4″ inch thick so that it could fit a picture frame.
As you may know, scoring a large piece of glass, whether thick or thin, and then creating a clean break along that score line is fairly easy to do without many issues. All that requires is to place the scoreline face up but lined up on the edge of a table and apply downward pressure to the hangover glass piece until it snaps correctly.
However, have you ever had to cut a smaller piece of a thick glass?
It can be tough without the right tools. I recently tried to cut a piece off measuring a few inches away from the score line and it didn’t break clean all the way down.
I believe this happens because my hand pressure is too close to the score line, leaving little leverage, so the force isn’t distributed evenly all the way down the score line.
Tips for Cutting Thick, Short Glass Successfully
The most used technique to cut small glass pieces from a sheet is to use this bulb to tap the score line.
I am no expert in cutting glass sheets, but these tips may help for cutting thick but short pieces of glass:
- Measure & Cut from Larger Sheets– first try to cut from larger sheets to prevent or reduce the likelihood of having to cut off a short length glass section.
- Use the Tapping Technique– after a score line is made, you need to use the round metal knob that is usually on the end of the glass cutter handle. It is typically made of steel or brass that is sometimes the cap for oil reservoir cutters. Simply tap metal knob on the opposite side of the glass under the score line lightly like a hammer. Work from one side to the other to help create stress cracks then pry the glass down with your hands like you usually would. It should prevent your glass from breaking incorrectly and damaging it.
- Flat Nose Breaking Pliers– here are some flat nose pliers that you can use to help grab the smaller strips that need to be cut off and separated. You simply use them to pry the edge and strategically work your way down the glass.
- Glass Running Breaking Pliers– another way that might help is to use running breaking pliers which are bowed in a way that it will grab onto the glass and apply pressure at the same time to separate it along the score line. They actually press down on the score line w
- Simple Running pliers– this one on Amazon here works by gripping it with your hand with pressure directly over the score line to break it.
- Heavy Running Breaking Pliers– similar in operation to the previous, this one on Amazon may be better and can handle thicker glass but it is more expensive.
- Clamp End Pliers– these clamp end pliers on Amazon can also be used in a similar way by clamping an end of the glass along the score line to ensure the pressure break exactly along the line while also applying pressure to with your hands to separate.
If the Glass Doesn’t Break Correctly
If the glass ends up breaking where there is a small piece that can’t really be pried off, you may want to use this technique that I tried with a diamond cutter disc like these connected to a rotary tool. You will want something like a RotoZip or Dremel tool since drills are not fast enough. I used a dremel tool as shown below.
I simply used this too cut along the score line as consistently down and lightly as possible so that it wouldn’t build up too much heat. I used an old spray bottle from throat spray and filled it up with water. I occasionally sprayed the score line while I was cutting to reduce heat build up, help lubricate it and keep dust down.
Please use this with caution though. Too much heat may break the glass incorrectly and make things worse.
Thick Glass Cutter
Another thing to look into using is Toyo’s glass cutter designed for thick glass cutting as shown here. Apparently, this is designed to score the glass while doing a tapping technique at the same time to create deeper scores. Though, I have seen professionals use a regular cutter on 1/2″ thick glass with no issues.
Thank you for checking this out on cutting thicker glass and small pieces. Have you tried any of these techniques or suggest a better way? Please leave a comment below.
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A different wheel having a different angle designed for thicker glass is the best to use and there won’t be a problem with seperating the two pieces.
Thank you, Dave. Is this different wheel you refer to the one included in the thick glass cutter linked in the above? Or is there a different cutter you could point us to or a certain angle we can search for to achieve this?
I appreciate your suggestions, as I am sure everyone else does.
Eric, I found a glass cutter that can cut thick glass as well as floor tile. I’ve used it sucessfuly on 1/4″ thick mirror, no problems, even narrow strips 1/2″ wide. Im still practicing with it on curves & I have even had a measure of success doing it. The company is in Great Britton. “The Amazing Tile and Glass Cutter”. It sells for about $39.00 & comes with an extra cutting wheel. This tool is ment to be used with both hands (for better control & power depending on the thickness). The company also has some impressive video instructions on their website. I hope to have some pics to share some of my etchings soon. Just thought I’d pass along the info. Thank you for all your hard work keeping the rest of us informed and inspired.
Cynthia, thank you for sharing and it looks promising. I was searching for it in the US and found something similar here http://amzn.to/2GuXCw5
Nice post. Thanks for sharing. I love making my own props. It is fun, and in my case gives me a reason to break out the Dremel 🙂
Dave I’m cutting 1/8th thick mirror. I’m trying to get two cuts out of a 12” square cutting straight lines with a 1/2 left over. I keep trying to snap this piece off but I’m not sure if I have a good line from my Lowe’s cutting hand tool. I keep breaking into the largest piece of glass or mirror in this case. Thanks if I can get some feedback on this problem.