Thread: Red Hot Router Dust

Check the sharpness of the bit too Mick

Originally Posted by NCArcher

Check the sharpness of the bit too Mick

I ran a thumb across it before fixing it into the chuck and it seemed sharp enough. Nevertheless a quick run across a stone won't do it any harm. Shallower cuts is the main lesson learned. I've never come close to encountering the possibility of fire so this was a salutary lesson.

mick

You may also want to consider feed speeds, a slow feed generally leaves the bit rubbing against the sides of the cut, heating the timber, the bit and the swarf. A faster feed (if the router and bit can cope) reduces the rubbing effect and heating. An open sided cut, like edge profiling or rebating, allows the swarf to be ejected, whereas a closed cut like a dado traps the dust between the walls of the cut, the base of the cut and the router base unless you can apply truly effective dust collection very close to the bit, in which case you would not find a lot of material in the dado.

Smoke detector in the bin? I don't know if it would work or the dust would set it off, Tony might have some idea on that.

Originally Posted by Chris Parks

Smoke detector in the bin? I don't know if it would work or the dust would set it off, Tony might have some idea on that.

I just replaced a 10 year old domestic smoke detector in the metal work end of the shed because it started going off all the time and I suspect it is contaminated with fumes and dust.
The instructions on the new one says, "Do not install in dusty, dirty areas when loose particles can interfere with with smoke alarm operations"

There are fancy smoke specific detectors that work better in dustier environments by filtering out dust.
eg https://www.systemsensor.ca/es/docs/guides/A05-1005.pdf

The filters have to be regularly cleaned and in some cases eventually replaced.
However as its sou dusty inside a DC dustbin the filter would probably only last for a very short period before needing attention.

I guess I posted this story to remind people that it CAN happen. However it's a rare phenomenon in my limited experience so the concept of smoke detector in the dusty receptacle could be a step too far towards safety.

Camphorwood is obviously chock-a-block full of aromatic substances, all of which likely have a flash point lower than the normal compounds found in most other timbers. Sandalwood might come close.

mick

I did a post on this forum a lot of years ago, but I can't find it now. In my early days of woodturning I was using a wire tool to mark rings on some knife handles and I obviously got too enthusiastic and some embers dropped into the shavings below. Less than a few minutes later I had cental heating in the Camphor shavings. I clean up every day now and if I get any smoking shavings from tools or drill bits, I vacuum up everything with the shop vac and then leave it outside overnight before emptying it.
In my job I attended a shed fire due to a similar situation, so I became paranoid about fire safety and practice it every day.
Rgds,
Crocy.

I've held back on commenting on this thread - because I get tired of the "safety nazi" labels people want to throw about. However it never ceases to amaze me how casual, complacent or is that ignorant some turners are about fire safety and other hazards.

I cringe when I see videos of a turner,

• "flashing off" alcohol from a dye applied to a turning,
• "charing" a piece with a burner,
• an angle grinder to make a quick cut or two,
• using very dull forstner bits into end grain,
• or thick layers of over spray in a small "spray booth",
• rags used to apply "drying oils" left about the place,
• fractal burning,
• ......

with shavings piled up on the floor, on the lathe, or with quite high levels of air borne dust in their shops.

It gets back to my training in hazard / risk management - is it likely, or even remotely possible to occur? what are the possible outcomes?

How many fires have been created in the open from some one performing "hot work" on a day or in conditions that made the small task one of high risk?

A smoldering ember has a surprising life span in the "right" environment and can lead to a total loss of a shed, its contents, and possibly even neighboring buildings / property. Fires in dust control systems are quite common.

There have been numerous formal investigations of some quite spectacular fires and explosions resulting from "spontaneous" combustion of high buildups of nitro cellulose lacquer over spray; and cascading explosions of dust in particle board / card board manufacturing plants, or workshops using those and other wood / cellulose products from seemingly "small risk / low hazard" tasks that went horribly wrong.

One in particular was a relatively simple task to change out light fixtures in a manufacturing facility. Employees were in a EWP with a "dust curtain" employed to shroud the work area. A spark was generated in the dust laden environment which created a "small explosion" and resulting spot fires, that dislodged more dust, which created more explosions - leading to total loss of a very large facility.

I know of at least three local "catastrophic" fires attributed to "oiled rags" left in a heap in newly renovated Queenslanders.

Often the "primary" hazard, sets in motion a runaway train of uncontrolled / uncontrollable "secondary" events.

japanesescreensandinteriors_486407.pdf (coronerscourt.vic.gov.au)

The Potential for Dust Explosions in Dust Collection Systems – Baghouse.com