Just a heads up

[DonHo]

Yesterday I cut a stopped dado on my router table and as usual the dado(grove) was filled with wood dust after the cut. Without thinking I knocked the dust out of the dado into a trash can that was nearby. About 10 min later I smelled something weird and found the source to be the trash can. It seems that somehow the dust was hot enough to start some of the paper and plastic in the trash can to smoldering. Has anyone else had this experience?
I've cut several dado's on the router table and never had this problem before. On the other hand this may be the first time that I dumped the dust in a trash can right after the cut, I don't remember doing it before. Anyway someone was looking out for me and I discovered it before it caused any real trouble. I won't be cleaning out my router dust directly into the trash can again.
DonHo

[wardprobst]

Yesterday I cut a stopped dado on my router table and as usual the dado(grove) was filled with wood dust after the cut. Without thinking I knocked the dust out of the dado into a trash can that was nearby. About 10 min later I smelled something weird and found the source to be the trash can. It seems that somehow the dust was hot enough to start some of the paper and plastic in the trash can to smoldering. Has anyone else had this experience?
I've cut several dado's on the router table and never had this problem before. On the other hand this may be the first time that I dumped the dust in a trash can right after the cut, I don't remember doing it before. Anyway someone was looking out for me and I discovered it before it caused any real trouble. I won't be cleaning out my router dust directly into the trash can again.
DonHo

I'd check your router bit under magnification to see if you lost a bit of metal or your edge has dulled severely.
DP

[SARGE..g-47]

Sounds as if you were taking too big a bite Don and the wood had over-heated to the point it ignited. Or.... you didn't happen to have thrown away any rags in that same trash can that you had used to apply or take off tung, linseed or similar oil did you? If so the heat from the dust could have caused combustion on that rag.

I have seen someone wad up a used rag loaded with linseed, etc. and stick it between fence post. And hour later we saw the fence on fire. If anyone is not familar with the heat created by not properly airing out an oil filled rag before disposal, read.. ask questions and get familar as it is an accident waiting for an opportunity.

Regards and back to lumber-jacking in my yard.. break is over... :>)

[DonHo]

I think you probably right about too big a bite. The dado was 3/4 wide by 3/8 deep, I probably should have taken at least 2 passes.

I'm pretty careful about rags I use to apply oil finishes, I hang them on the close line and then throw them in the trash that I'm setting out to be picked up.

I'm pretty sure the bit was/is OK so it probably was the heat generated by too large a bite. I'll need to remember that in the future.

DonHo

[MilDoc]

Many years ago (my first very brief sojourn into woodworking) I actually started a piece of wood on fire while routing a dado!

[gsmittle]

Essentially the same thing happened to a couple of my students last year. They were using a circle jig with the router to cut some large plywood discs and one of them had the bright idea to suck up the dust with the shop vac.

The hot dust burned a hole in the paper and foam filters. Fortunately, another student saw the smoke coming OUT of the shop vac and doused the flaming filters in the snow outside.

g.

[SARGE..g-47]

Sounds as if you have the situation nailed down, Don. Heat generated from too large a bite can also cause kick-back in some cirmcumstances. You can scorch that bit and dis-temper it is another reason to add to the "no-no" list.

The good news all is well.. you are safe and the shop didn't burn down.

Regards...