Burning sawdust in my SawStop PCS

[Bill Sutherland]

Today I had some burning/binding on my Freud plywood blade. Probably should not have used it cutting the lid off a small oak box. I did notice the burning smell on the blade and it came across my mind that the small amount of sawdust in the bottom of my PCS could ignite if somehow a ember was hot enough. Anyone ever heard of this.

[Andrew Seemann]

Having tried to burn sawdust in the fire ring to get rid of it, I can tell you sawdust burns very smokily and actually quite poorly. It is really hard to sustain a flame with plain sawdust. If you manage to get one, it burns the outer surface and then wants to go out and just smoke. Planer shavings burn much better, but even they sometimes can be difficult if the curl is too tight.

Even though some woods burn quite easily (cherry, maple, oak) it would seem rather difficult to get an ember off of one and have it stay lit all the way to the bottom of the saw, although it is probably possible. If it did happen, you likely would get a lot of smoke out of the machine before you had flame. If that does happen though, have a fire extinguisher ready before you open the saw, the rush of air might help a flame catch at that point.

[Steve Eure]

I've never had that happen on a table saw to my knowledge, but have on a router table. I too think that the small chips would be hard to stay ignited but not the dust. With the router, I've noticed when it happened that the dust would spit fire (puff), for lack of a better word, and immediately go out. I always worried that the dust collector or vacuum would catch fire, but never has.

[Lee Schierer]

When cutting the lid off of a box, you can cut any two opposites sides with no problem. I usually choose to cut the longest sides first. Then you need to put a spacer the size of the blade into the cuts to prevent the lid from moving into the blade as you cut the third and fourth side of the box. to prevent burning in the cut it also helps to make sure your blade is perfectly aligned with the miter slot and the fence is also perfectly aligned with the same miter slot.

[Steve Demuth]

Today I had some burning/binding on my Freud plywood blade. Probably should not have used it cutting the lid off a small oak box. I did notice the burning smell on the blade and it came across my mind that the small amount of sawdust in the bottom of my PCS could ignite if somehow a ember was hot enough. Anyone ever heard of this.

The risk is extremely low. Unpacked, single grains of sawdust don't generate enough heat from combustion to ignite neighboring loosely associated grains. Wood is ignited primarily by heat from the ignition source cooking out volatile hydrocarbons that ignite easily, and the small amount a single ember can coax from it's neighbors is quickly diluted to non-combustible concentrations in all the air in loose dust. So a loose sawdust fire is very difficult to make self-sustaining.

[Peter Christensen]

I've seen it twice before where embers in the bottom of the saw got hot enough to start smoking. It was from wood pinching the blade while ripping.

[Barry Block]

When cutting the lid off of a box, you can cut any two opposites sides with no problem. I usually choose to cut the longest sides first. Then you need to put a spacer the size of the blade into the cuts to prevent the lid from moving into the blade as you cut the third and fourth side of the box. to prevent burning in the cut it also helps to make sure your blade is perfectly aligned with the miter slot and the fence is also perfectly aligned with the same miter slot.

Putting a spacer is one way to do it that I hadn't thought of, I'll have to try it. I just don't raise the blade high enough to cut all the way through. I leave a 64th or less then I remove lid with a knife or flush cut saw and a few passes with a block plane and your all set.

[Barry Block]

I actually use turning shaving as fire starter in my fireplace which work really well. On a day when I didn't have any I threw a couple handfuls of saw dust under the grate. It didn't work. As mentioned above it pretty much just smoked the top layer and went out.