It’s all in the way you slice it. And the way you slice it is, apparently, profoundly affected by a good blade.

Check any glassmaker’s forum and you’ll find someone whose tile saw cuts glass about as well as a wood chipper. They run a pattern bar through the thing and instead of slices, they get frit.

This post is about how to fix that.

Not that I have any special expertise at using tile saws, mind you. What I DO have is a cheap, very badly made and out-of-true Chinese tile saw I got on eBay many years ago. Figuring out how to make it give me the cuts I need has taught me a lot.

I needed to tile a bathroom (who puts white carpet under a TOILET?), laundry room, and studio–FAST–before my furniture arrived. I spent all my money on the house, so that $100 tile saw was all I could afford.

My brother-in-law (the construction manager) arrived to lend a hand, and sniffed at that saw. “THAT,” he said, “Is the crappiest saw I’ve ever seen. It’ll never last.”

That was in 2003 (hah, Jerald!), and it’s been my primary glass cutting saw ever since. It makes remarkably fine cuts in glass sheet, sculpture, and pattern bar…such as the pattern bar slices shown at the right. These were taken from murrini cane bars, from top to bottom:*

  • Thin (~2mm)  Bullseye Gold Purple (for reference)
  • 3mm Bullseye Marigold Yellow (for reference)
  • A series of pattern bar slices I’ve tried at various thicknesses. The thinnest (sixth from the top) is only 1.5mm thick, thinner than that piece of gold purple.

I make these cuts pretty consistently with this saw, have been doing this for years. So…must be doing SOMEthing right…right?

This is probably going to be boring (and redundant) for most glassworkers, but I thought I’d get all my saw work info down in a single post. I am NOT pretending to be an expert in shop equipment terminology (as you can see by the updates/comments in the three years since it was originally written), or the last word in how to coldwork.

There are already some excellent tutorials and videos on using tile saws to cut glass, so it’s not really about how YOU should do it. If you’re not sure of the basics, I STRONGLY urge you to buy Johnathan Schmuck‘s (he has changed his name, BTW, to Johnathan Turner) very good book on coldworking. You can also find a number of really great online tutorials on cutting with tilesaws, maintaining your saw and similar subjects. (Check out, for example, the excellent series on the HIS Glassworks YouTube channel).

I’ve studied those, taken classes from these guys and more, and made a LOT of dumb mista…, er LEARNING EXPERIENCES, on my own. It’s given me the following rules of the tile saw road:

Caveat–this works for me; YOUR mileage may vary. And these rules will never be complete so, please, please, help them grow by adding your comments and suggestions.

Cheap eBay tilesaw from 2003, $100 including stand and three diamond blades. Great deal but lousy saw…

1. The most important part of my tilesaw is the blade.
My tilesaw came with three cheap, thick (2mm, or about .085 inches, thick) diamond blades. I was happy to get them, they’re great for making rough cuts for later coldworking. They’re also not bad for cutting ceramic tile.

My old blade cuts a kerf about 1/8 inch (3mm). A dozen cuts with this blade wastes 3/4 inch of glass!

But my goodness do they take a HUGE kerf (that’s the bite created by the width of the blade). I’m losing around 3mm PER SLICE (right), which really adds up.

Worse, if I’m very careful, I can get them to slice the glass to about 3/8 inch with only a little breaking or chipping…but no narrower.

I complained to expert coldworker Marty Kremer. His solution? “Buy a decent blade.”

Yup.

On his recommendation I chose a 10-inch Result blade from HIS. It’s half the thickness of those old blades–0.04 inches or a little more than 1mm thick–and makes a huge difference in the quality of my cuts. I have much less chipout (the chunks that fly off the edges of the cut). Kerfs are less than half the previous size so I waste less glass.

The best part: Thin slices. I can slice a 2 inch thick block of glass, 10 inches long, into slices between 1mm and 2mm thick, or thinner than a US dime. I can get more slices per block, important when you’re squeezing as much as possible out of a unique pattern bar.

Another benefit: Thin slices open up a wider color palette for pattern bars, since you can use darker, more saturated colors. Normally can be the kiss of death in pattern bars; any thickness at all and they start looking black. The thinner I can slice the bar, the less I have to worry about loss of detail.

The square on the left is a 6mm (1/4 inch) thick piece of pattern bar. The two slices on the right are 1.5mm and 2mm thick, respectively. The center slice shows far more of the layer detail.

The picture below on the left shows why. I’ve cut three slices of the same pattern bar, which used gold purple, cobalt blue and carnelian. Normally, those colors would all be far too dark for a pattern bar. The first slice, on the far left, is about 6mm thick and shows why: The only real detail you see are white spots and a little orange.

Now look at the second slice. It’s a quarter of that thickness, 1.5mm, and the third is 2mm thick. Notice how much more detail is visible in the center slice–and even how much brighter it is than the slice on the right.

And, interestingly enough, this blade cuts about twice as fast as my glass-chewing old blades!

2. I must control blade wobble.
There’s probably an expert term for “side-to-side movement of a saw blade on a fast-moving spindle” (see below, from Chaniarts–it’s called “runout”) but I just call it wobble. A saw blade can wobble because there’s some play in the way it’s attached to the spindle/axle-thingy (the nut’s not firmly tightened, or has vibrated loose, for example). Or, as might happen with the thin Result blade, the blade can be thin enough that it flexes at high speed.

A wobbly blade can widen the saw kerf, make a rougher, wider cut that wastes glass, and is also more likely to chip or break the glass.

Obviously, tightening the nuts that hold the blade on the spindle is part of the solution, but I also invested in blade stabilizers from HIS (I think they call them “wheel stiffeners.”) The stabilizers look like great big washers–I suppose if you could find great big washers they’d work as well–and they go on the spindle on either side of the blade to prevent wobble.

They definitely make a difference–less chipout. The downside is you lose some depth in your cuts–without stabilizers, my 10-inch tilesaw can cut a maximum depth of almost 4 inches (although that’s puuuushing it). With the new stabilizers, I have a tiny bit more than 2 inches. But the cuts I can make are almost exactly the width of the blade, without chips.

3. The deeper or thinner the cut, the more water I use.
A moderate trickle of water against the blade suffices when I’m cutting flat (6-9mm) pieces of glass. I find I must really pile on the water, however, when cutting thick pattern bar, castings or murrini slices.

I invested in some Loc-line hoses (left), one for each side of the blade. I aim one at the blade that’s in the cut, right at the base. The other I position so it’s shooting water into the cut, almost on top of the front edge of the blade. Then I attach the garden hose and turn on a nice stream–if I’m not getting drenched, I can’t cut as thin. (Again, experts may have a better way to do this).

The loc-lines make it easy to position water exactly where I want it. I adjust the water position every time the cutting depth changes, which is why the easily adjustable loc-lines are so important.

I do NOT recirculate water from a pump in the reservoir–it doesn’t work all that well on my saw anyway, and when the water clouds up my cutting action suffers. So I use fresh water, and accept that I’ll be sending a stream of water down my driveway (where it excites comment from my water-conserving neighbors).

4. I use sacrifice glass to prevent blowouts and lost corners.
A traveling saw blade puts a lot of pressure on the last little bit of glass going through the saw, which can blow out the back of the hole, or knock off that last corner. This is a problem in woodworking, too; woodworkers solve it by putting a piece of scrap wood behind whatever’s being cut.

So do I; only I stick a piece of glass behind the piece I’m cutting on the tile saw and make the cut continuous through the sacrifice piece. That way, any breaks happen in the sacrifice piece, not the real thing.

This can be tricky to get right because the two pieces of glass must connect or the first will crack without affecting the sacrifice piece. Typically, the sacrifice piece can vibrate loose and you the back anyway. If the glass is perfectly flat, I use a little water between them and let suction hold them together, and secure them with a tight wrap of duct tape. Or I superglue them together (VERY lightly) Usually I get the glass wet enough that you can separate them later.

HIS sells a special sticky wax, “Stacking Wax,” that can be used for the same purpose. I haven’t tried it, so I don’t know how easy it is to use. If you have, let me know how it works.

I’ve been told that you can also use stacking wax, other soft, sticky wax or an adhesive-backed vinyl or lamination layer by itself in much the same way, without the sacrificial glass. Apply it to the back of the glass and make your cut; it’s supposed to hold the glass together to prevent the initial crack that starts a blowout. Again, I haven’t tried it, so I’m not sure that it works.

5. I ensure my feed table is straight and true to the blade.
Yeah, right. To put it bluntly (hah!), mine isn’t true and it isn’t adjustable, which is a big headache. At best, it can cause my slices to get fatter or thinner as I move along. If I’m not careful, it also can put pressure on one side of the slice, and cause it to break.

I compensate by making my own jigs to line up the glass. I true THOSE to the saw, which sorta works. I fully intend to use my el-cheapo saw until it dies…but if anything could make me break down and buy a good saw before that, that daggone feed table would do it.

6. I don’t mess around with a good blade.
I use my cheap blades for freehand carving in the glass, kinda like chainsaw sculpture in wood. You bring the glass to the bare, moving blade and use it to dig into the glass and rough out your shape, literally whittling things down. I do NOT do that with the Result blade. It’s possible to torque a thick piece of glass when you’re in the middle of a freehand cut, with an outside chance that it would damage the blade.

I do sometimes make freehand cuts with the Result blade if I need to quickly cut a thick piece down to size. I just don’t expect it to be accurate because I know I’m not going to hold that piece perfectly straight all the way through to the end of the feed.

If the bottom of the glass doesn’t sit flat on the table I’ll try to stabilize it with a shim instead of just holding it upright. I’m not that worried about tilting the glass and bending the blade, but I am liable to change the angle of the blade’s attack, which increases the likelihood of chipping or breaking the glass.

I keep a supply of “craft sticks,” AKA popsicle sticks, on the saw table just for this purpose. They’re inexpensive and reusable, and long enough that I can usually manipulate a couple around under the glass until it stops wobbling.

7. I take CARE of that blade.
Result blades–or any good glass saw blade–aren’t cheap. I clean off the glass particles, dry the blade and periodically clean and lubricate it between uses.

When I’m using it, I never push a cut. If it changes noise/pitch in unexpected ways while I’m cutting, or I start seeing a lot of chipping in the glass, I stop and figure out what’s going on before I proceed. I may beat that saw to death…but the blade gets gentle treatment.

If I’m hacking through a lot of glass fast and don’t need the thin, smooth slices, I swap out the Result for one of the old diamond blades–no need to waste a fine blade on thick cuts. I also dress the blade when it appears to be slowing down. HIS and other places sell dressing sticks for this purpose; I use broken mullite kilnshelves to expose fresh diamond in the blade, and it seems to work fine.

And that’s it. Nothing magical, and I’m probably doing something I shouldn’t, technically speaking. But I’m getting the cuts I need.

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*Technically, what I’m making is pattern bar, i.e., stacked or dripped glass block that makes beautiful, Rorschach-like patterns when sliced open and combined. I call what I’m making “murrini cane stock,” essentially pattern bar with a tiny, repeating pattern. It’s designed to be sliced into identical bars (cane) that can be sliced up into murrine.

Awhile back I made and hundreds hundreds of cabochons for buttons, pendants, earrings and rings from the pattern bar stock I built out of these experiments, and I still have maybe 2/3 of that stock left. If you’d like to see how these were made, check out these posts–the “sandwich” post talks about the bars: