How to CUT GLASS.

Loads of useful TIPS on how to cut glass. Mainly aimed at the tiffany world but also useful for general glass cutting.

Including the following:-

1. Designing and trial with card.
2. Maximising glass by careful layout.
3. Bulk cutting to average out errors. Measuring technique, and cutting multiples.
4. Technique of cutting glass.
5. Alternative methods of breaking glass.
6. Different types of glass, and the best side to cut.
7. Different types of glass cutter.

Step 1: Designing and Trial With Card.​

This is the first and most creative step. Designing the lamp and then trialing the shape using cardboard.

This is how i start all my lamp projects.

1. Take a piece of paper and draw the side profile. if larger than one sheet of paper join two sheets and trace the half.
2. If you are happy with the shape and general proportions test to see how the chosen light bulb will fit.
3. Next you have to choose how many layers (rows) you will divide the shape into. consider the amount of work lots of rows will take compared with the shape compromise with less.
4. Now you need to decide how many sides you want. again the more you have the more flowing and smooth the lamp will look, but the more time and fiddly the bits will be. ALSO i believe you are better off having and even number of sides, that way you can alternate the colours.
5. Now you need to work out the size of all the bits and if you wish make up the lamp with cardboard.
6. Finally if you are happy with your shape then spend some time working out the amount of glass you will need and whether you will have to use different colours?

Step 2: Maximising Glass by Careful Layout.

I cover this part a lot in the video.

Basically you need to maximise the amount of glass whilst working within the limit of the glass! AND consider/realise that you don't need to allow for a cutting (blade) thickness.

In the picture above you can see how i have cut the 12 sections of glass needed and made the most of the glass width. If you watch the video you will see i failed on one of the white pieces, thankfully i didn't fail on the purple as the picture shows.

Step 3: Bulk Cutting to Average Out Errors. Measuring Technique, and Cutting Multiples.

This is obvious to me but maybe that's because i have an engineering background? So sorry if i am telling you how to suck eggs but i need to explain this bit.

Firstly work out the sizes of the bits you need and then work out the values you will need to mark out along a rule. Don't mark the first dimension then reposition the rule to mark out the second. WORK FROM A DATUM which is normally the edge of the glass. Then work out all the cumulative dimensions along the ruler and mark out all at once. (even include the distance in from the edge if required) I work out the measurements on a spreadsheet for all the layers.

If you can't fit enough on one row then you may as well cut the bits you can fit so there is room left at each end.

1. Mark out the number of rows you will need, using the top edge as a datum and adding the distances as you go. I.E height needed to be is 63mm so mark out 63mm then 126mm then 189mm and lastly 252mm.
2. Cut the rows out first.
3. Mark out the top and bottom of each row using the technique explained above.
4. Line up the number of rows so all can be cut at once.
5. Once cut line up again cutting as many as you can.
6. Repeat the multiple cutting until all are done.

Basically the above method averages out errors. if you cut one bit to big then you will have a corresponding small bit.

If you attempt to cut just one bit, then cut another bit and so on then you may find you end up with all the bits too big, and you really want to avoid that!

Step 4: Technique of Cutting Glass.

The video shows this step very well. (and much better than i can explain)

1. Working on a stable workbench and with a suitable guide make sure the glass and guide cant slide around.
2. Make sure the guide is positioned correctly so the cutter wheel is on the marks.
3. Hold the cutter firmly and starting from the furthest edge make ONE FIRM PASS towards you.
4. Carefully lift up the glass (it may have already broken) and position a match (or needle) under the score line.
5. Apply firm pressure to either side of the score line and the glass should break.

AND that should be it. However it should be noted that different types of glass and even different colours of glass can cut differently. I tend to find that Red is the hardest to cut. If you are new to tiffany work and cutting glass then try to stick to hand blended/machine rolled. If you try the hand blended and hand rolled then it can be very uneven and a nightmare to cut.

Step 5: Alternative Methods of Braking Glass.

There may be occasions where using a match or needle under the score line to break the glass isn't suitable. Maybe (as shown in the video) you have cut very close to the edge. so you have a few other choices.

1. Find a glass cutter which has slots in the side (the one pictures on the left) then position the glass into the best fitting slot and apply pressure.
2. You can get a special tool for breaking glass. (see picture)
3. Or as shown in the video you can turn the glass over and tap along the score line from the other side and you should find the glass will break along the line. The disadvantage with this is that if you tap just a little bit off the score line then you can get a "messy break"

It should be noted that the blue tool is for straight lines only. If you are cutting curved shapes then the tapping on the reverse of the score is best.

The metal tool shown in the pictures is a special set of pliers which have a curved jaw on one side this allows you to grip the glass at the score line. However this only works if your score line is within the reach of the jaws.

Step 6: Different Types of Glass, and the Best Side to Cut.

Over the years i have been making tiffany items i have discovered that not all glass in the same. Different colours different textures, hand rolled/machine rolled. What i would suggest is start simple and use plain clear glass the type you would use in a greenhouse. Then once you have mastered the easy stuff then move onto harder types like hand blended/machine rolled and then harder still hand blended/hand rolled.

On every type of glass you will find there is a better side to cut. you should look for the more "glass" side which may sound daft but if you look closely you should see a slight pattern where the glass has been rolled, and generally cut on the other side.

Step 7: Different Types of Glass Cutter.

You can see in the picture that you can buy several types of glass cutter.

It really depends on how much glass cutting you are going to do? Whilst doing this instructable i tried the middle glass cutter and it was so blunt it really didn't make a scratch! However the cutter on the right is by far the best cutter, it has a receiver full of oil and everytime you push it down a little bit off oil is used to lubricate the wheel. However it is also the most money, so it really does make a difference for the extra money you pay.

I hope this instructable has been of some use to you and thanks for reading/watching.