Shopsmith Forums

I took this off Facebook, it seems strange to me that wood shavings could start a fire. Is it possible?

I feel it is important to let everyone know you should have a smoke detector in your workshop. Last night after my husband used a forstner bit to drill a hole in 3x3" block so I could make some mini vases. The wood shavings were hot, He put them in a cardboard box not thinking. I finished the vases up and polyed them in the shop. Went in the house less than 10 minutes later our son came home and announced the workshop was on fire.

I think we need to know 'the rest of the story'.

I would be willing to bet it was the poly and it self combusted ...

Just a theory ....

No useful info there, and could have been water based poly. Its only a duck if it walks, quacks, and looks like a duck.

Wood shavings and friction have been used for centuries to start fires. If there was some smoking while using the forstener bit (bit was dull or forced too hard to cut the hole can cause some burning) the shavings could have smouldered for hours before fully igniting themselves or other combustibles in the box.

Yes they can if. If the bit is dull and smokes while you are cutting it is possible that a flare up can occur. Even shavings from lathe work can get very hot. I can remember several cases when I was doing some lathe work that I had to cover my left thumb with band aids because the shavings were uncomfortably warm. Remember the old adage "if there is smoke there is fire" or at least the possibility thereof.
The next time you use a forstner bit watch how fast the shavings come off the work and think how much you would sweat if you did the same with a block plane.
Bill V

I agree that wood shavings could have started the fire, but rags with chemicals such as poly can also.

In fact I think spontaneous combustion of chemical soaked rags is the number 1 reason for most shop fires. Tung oil is especially prone to this.

I think that Ed has it right. Most of the oil based finishes release heat as they cure. The fancy term is "exothermic".
Also be careful of CA glue when used as a finish. If you work that too much as you apply it, it will heat very fast and I have even had some paper towel turn brown and smoke when I was finishing some pens.
I use small squares of old "T" shirts to apply the wipe on poly finishes and when done I spread them out on the bench to let them dry and then trash them.
Bill V

I think a smoke detector might be a good thing in a shop(be prepared for spurious noise when sanding etc.), but in that case other actions could have prevented the fire rather than detecting it.

Sharp bits. Not forcing bit(especially a dull one). Not leaving 'damp' rags to 'dry' in a heap.



A smoke detector is like a motion detector in a barn(verification of presence). Once the livestock has left through the unlocked(open) door, it is too late to stop them.

wa2crk wrote:Yes they can if. If the bit is dull and smokes while you are cutting it is possible that a flare up can occur. Even shavings from lathe work can get very hot. I can remember several cases when I was doing some lathe work that I had to cover my left thumb with band aids because the shavings were uncomfortably warm. Remember the old adage "if there is smoke there is fire" or at least the possibility thereof.
The next time you use a forester bit watch how fast the shavings come off the work and think how much you would sweat if you did the same with a block plane.
Bill V

I can see this happening using a dull forester bit, just never thought about it but will now. I have burned a few holes. I have used a leather glove on my left hand because the shavings were so hot coming from the lathe.