Replies

1. 
   JohnWW | Oct 29, 2004 09:15pm | #1

   Putting a glass blade, and cooling, and a dust/shard catcher on a woodworking saw would theoretically be possible, but it would be an engineering challenge and probably not practical from a time and money point of view.

   John W.

2. 
   UncleDunc | Oct 29, 2004 09:47pm | #2

   I suspect that dust suppression is even more important for glass cutting than it is for wood cutting. Silicosis is serious business.

   Given the amount of air that a bandsaw blade goes through before it comes back around for another cut, I'm not sure cooling is a big issue.

   Another question is blade speed. I know wood cutting bandsaws run about ten times as fast as metal cutting bandsaws. If the ideal glass cutting speed is very different from the ideal wood cutting speed, you'd have make some kind of adaptation to get good performance.

1. 
   DennisS | Oct 30, 2004 06:43am | #6

   Unc -

   I think the coolant is intended to keep the glass cool rather than the blade. The heat buildup at the point of cut would cause the glass to break I would think.

   I'm gonna check out the site referenced in another post with respect to the specialized saw for cutting glass, but whatever the price I would think it would be far preferable to buy that saw than to muck up an otherwise perfectly good woodworking bandsaw! (grin)

   ...........

   From Beautiful Skagit Co. Wa.

   Dennis

1. 
   UncleDunc | Oct 30, 2004 11:59am | #8

   Good point. I know glass can take some localized heating from soldering the cames, but that might not be true at the root of a saw kerf.

2. 
   WayneL5 | Oct 30, 2004 06:40pm | #11

   The primary purpose of the coolant is to keep the blade cool, but keeping the glass cool is beneficial, too.

   Diamond blades consist of diamonds attached to the blade with some sort of base material, called the "bond".  There are essentially three broad classes of bond:  metal bonded, resin bonded, and electroplated.  When a diamond is pressed against the material to be cut and moved real fast, it gets hot.  If it gets too hot it softens or melts the bond, and the diamonds fall out.

   The coolant takes heat away from the diamond so the bond doesn't fail.  Therefore, cooling greatly extends the life of the blade.

   If too many diamonds fall out at once, all you've got rubbing against the glass is the bond, which won't cut, it just heats up wicked fast from friction.  The blade is dull.

   Plain water is an adequate coolant.  The additives which are added when you use a commercial coolant provide some additional benefits.  First, water won't wet diamonds.  In other words, water will bead up and not spread out to form an intimate film with the surface.  It's like raindrops on a freshly waxed car.  Without the wetting, there is less heat transfer between the diamond and the fluid, and the diamonds run hotter.  Coolants contain wetting agents so intimate contact is achieved and the cooling ability is increased.  Commercial coolants also contain rust inhibitors to keep the machine from rusting.

   In cutting glass by hand on a bandsaw there are several things in your favor which lessen the need to use a coolant vs. plain water.  One is that you are feeding by hand, so can adjust the speed to keep from firing up the blade.  Another is that the cutting distance is a fraction of an inch, and the rest of the blade travel allows time for the diamonds to cool.  This is much easier on the diamonds, than, say, core drilling in which the diamonds are in continuous contact with the glass.  When core drilling, cooling is absolutely necessary.

3. 
   jackplane | Oct 29, 2004 09:55pm | #3

   Unless you have that specialized bandsaw, I'd never use a regular bandsaw for this unless you have a blade with very fine teeth, like 12 or more tpi, or a special abrasive blade. As Dunc said silicosis is an issue except when a constant water bath is used.

   
   

   ---

   Edited 10/29/2004 2:56 pm ET by JACKPLANE

1. 
   UncleDunc | Oct 30, 2004 11:56am | #7

   >> ... or a special abrasive blade.

   Yep. The commercial glass saws all have diamond blades. I don't think a steel or even a carbide blade would do anything but chip or break glass, no matter how fine the pitch.

4. 
   RickL | Oct 29, 2004 10:02pm | #4

   http://www.delphiglass.com/index.cfm?itemsysid=171770&page=itemView

   A different bandsaw from a wood bandsaw. For $200 for a glass cutting saw is pretty cheap. Get one for glass and one for wood

   The blade on the Delphi is half the cost of the saw. A diamond blade for a wood bandsaw is going to cost more than the complete Delphi saw and by the time you rig up the water cooling system plus you will start the saw rusting. Seperates are the way to go in my opinion.

5. 
   WayneL5 | Oct 30, 2004 04:15am | #5

   It would be difficult to supply coolant without endangering yourself by risking getting it in the motor.  Without a rust inhibitor, you'd wreck your machine, and with a rust inhibitor you'd leave a messy film all over your machine.

   Cutting glass (with a proper blade and saw) goes better with a coolant rather than plain water.  Most coolants are soluble oils that are added at a fairly low concentration to water.  Many of the metal working coolants will also do fine on glass.  But for the type of work you're doing, plain water would probably be fine.

6. 
   bones | Oct 30, 2004 03:59pm | #9

   My wife does glass and has been asking for a saw to cut glass. The blades are diamond and the saw supplies coolant to cut. There are a few different types, but the one she is wanting is called a wire saw. It is a round diamond blade. It is about $300.00 for a good one, and the blades are about $60-$80.  There are cheaper band saws that look like miniature woodworking band saws for around 200. They use diamond edged blades. There are conflicting opinion on wether they weaken the glass and cause more breakage and in turn require more repair than hand cut glass. My wife found as many posters on her glass forum for them as were against them. Woodworking and stained glass together will make some beautiful pieces. My wife will make mine for me. Good luck

7. 
   Len | Oct 30, 2004 06:19pm | #10

   I wouldn't use a woodworking band saw for cutting glass. You need to buy a specialized band saw. I have used this brand for several years. I would recommend you check them out.

   http://www.diamondsaws.com/index.cfm

   I have both the Laser 3000 and 5000.

   Here's another web site that carries several types.

   http://www.glassmart.com/

   Hope this helps.

   Hi, I'm Len and I'm a Toolaholic...
1. 
   bones | Oct 30, 2004 10:45pm | #12

   My wife has asked for the 3000. Is it a good saw. The 5000 is twice the money, but is it twice the saw? Plus, she has been concerned about the comments that glass cut with a saw is more prone to break. Have you experienced that?

1. 
   Len | Oct 31, 2004 03:35am | #13

   I don't know if it's twice the saw. It definitely has more power and the blade guides and tension is better.

   The 5000 has a reticulating pump but I would recommend not using the same water. I use a five gallon bucket and put the pump in there. The water that is used goes to another bucket.

   re. "Plus, she has been concerned about the comments that glass cut with a saw is more prone to break."

   I don't have any of those concerns. We often cut optical lenses and never had a lens break. The blade is diamond coated so it really grinds the glass away rather than cutting. I grind glass with a silicon carbide wheel as well with no concern of breakage.

   Hope this helps.Hi, I'm Len and I'm a Toolaholic...

1. 
   UncleDunc | Oct 31, 2004 05:27am | #14

   >> ... I would recommend not using the same water.

   Why not?

1. 
   Len | Oct 31, 2004 05:43pm | #16

   Hey Uncle Dunc!

   I found that the glass particles clog the pump and the coat the glass your cutting. Fresh water flushes the particles. But I am not cutting glass used for stain glass. I cut optical and dichroic coated glass.

   Hi, I'm Len and I'm a Toolaholic...

8. 
   mudman | Oct 31, 2004 06:44am | #15

   My wife is a very talented glass artist (if I may say so). She does stained glass and fusing in a giant kiln. We have tried several glass saws and they all seem to be lacking. The most affordable are the Griffen (sp?) wire saws, starting at $200. But all wire saws give bad cuts because of the blade motion. They dont work like a wood working scroll saw. We have a ring saw that cuts a lot better but is limitted in what it can cut. True band saws are VERY evpensive, and that is comming from a guy with $3,000 worth of kilns alone. My advise...... get better at using a scoring tool, and try different brands of glass. my wife can cut the most absurdly imposible cuts with a scoring wheel and that funny plastic running tool that you have probably seen. Do you have a grinder yet? That would come first.

   Mike

   please excuse my spelling.