Beating The Dead Horse - Define Dust vs Chip Collection

[Mike Shields]

It is called dust collection for a reason right?

As I consider the serious inadeqacies (from everything I've been reading on the subject) of my hobbyist dust/chip collection setup (which is moving from tool to tool with no tablesaw overhead collecting) the question comes up:

what is the main goal of collection for a woodworker?

IIRC, little CFM is required to suspend dust. So what is all the hoopla about mega-CFM collectors and 12" pipings (joking of course)?

Did we get off track somewhere regarding collecting dust? Or, have we including collecting chips, just for the convienence?

My sander makes dust, my planer and jointer make chips. My little Festool CT22 vacuum does an excellent job of collecting my ROS dust.

Comments please!

[Walt Caza]

Hi Mike,
nice can of worms you've got here...
My understanding is the higher cfm would be needed to capture dangerous
fine dust at source. Yes, it doesn't take much to suspend the dust and keep
it entrained in the flow, the trick is capturing it in the first place.
(that's my take from Mr. Pentz's worthy yet sprawling efforts)

A vacuum works by high pressure on lower volume, while d/c uses higher volumes of air movement.
Adequate volume is part of the equation, in which ductwork plays a huge role...
the other part is hoods and tool mods to capture the fine stuff right where it is created.

Chip collection cuts down sweeping, fine dust collection is life support.
Many woods are known carcinogens...yikes!
So much is written on d/c, and much of that seems contradictory...
simple answers can be hard to find,
but the topic remains important.

**just added:
The pic is my own solution to d/c. About a dozen yrs ago, as an otherwise healthy young man, I developed a nasty
and persistent wheeze. I was buying lifts of 50 sheets of MDF at a time, and building big booming custom car stereos
up to 10 hours a day without d/c. There was no internet for me, to research about formaldehyde glue in MDF
being a cancer causing agent. It took a while before I figured out that fine sawdust was ruining my health. Today I know better.
We can develop sensitivity and/or allergies suddenly and without warning, which can keep us out of the shop.
The lung association used to run an ad campaign "nothing else matters if you can't breathe".
My 5hp Oneida may sound like overkill to some, but in my shop...
I refer to it as my life support system.
be well,
Walt
:)

[michael osadchuk]

It is called dust collection for a reason right?

Did we get off track somewhere regarding collecting dust? Or, have we including collecting chips, just for the convienence?

My sander makes dust, my planer and jointer make chips.

Comments please!


Mike,

One of the interesting empirical findings in the use of a dust particle counter - such as the Dyclos one a number of us on this website bought in a group purchase around february this year - is that dust, measured anywhere between .5 and 5 microns, as well as over 5 microns - is generated in abundance, along with with big "chips", in wood working machine operations such as the table saw, planer and jointer work and not only or primarily in sanding functions.

....so the risk of harm to lungs because of ingesting dust particles is very much present even when what we typically notice in machine operations is a lot of big chips; a whole lot of small dust particles are accompanying the big chips.....

good luck

michael

[Chris Friesen]

IIRC, little CFM is required to suspend dust. So what is all the hoopla about mega-CFM collectors and 12" pipings (joking of course)?

Did we get off track somewhere regarding collecting dust? Or, have we including collecting chips, just for the convienence?

My sander makes dust, my planer and jointer make chips. My little Festool CT22 vacuum does an excellent job of collecting my ROS dust.

As mentioned before, little CFM is required to _suspend_ dust...the tricky part is capturing it the first place. It actually takes more airflow to capture fine dust than to suspend chips. So a good dust collector is basically automatically a good chip collector, but the reverse is not true.

Small hand tools generally have small dust collection ports. This requires high suction to pull a reasonable amount of air. Dust collectors are designed for large airflow and low suction, so a shopvac will generally do a much better job. On the other hand, if you tried putting your CT22 on a tablesaw, you'd likely find that it just doesn't move enough air to do an effective job.

[Frank Drew]

Without getting too involved in the semantics, you want to capture both dust and chips; I wouldn't work in a shop without an effective collection system. A shop ankle deep in chips, with chips and dust eventually on every horizontal surface like snowdrifts, is totally depressing, in addition to being both inefficient and dangerous. Which isn't to say that you can capture everything -- I never got an effective system for my jointer or lathe -- but certainly for the big offenders, the planer, table saw, sanders and routers.

My very first job in woodworking was in a custom millwork, and we ran many thousands of board feet of Old Pine (reclaimed heart pine). Since I was the newbie I was always on the catching end of the planer and there was no dust collection or even dust masks. Thank God it was pine and not MDF dust, as Walt experienced.

[Alan Schwabacher]

The term "chip collector" is a pejorative, invented to describe dust collectors that seem to work because they collect the big stuff you notice, but do not catch enough of the smaller particles to protect your lungs as would a bigger DC. There is little controversy over the idea that it takes a lot of air movement to capture a very large fraction of the smallest particles at the source. There is not too much controversy over whether there is some risk to some people in breathing these small particles. The controversies, as usual, are over how much risk there is, how much risk one is willing to take, and how much cost one is willing to bear to avoid that risk.

Some of the arguments on both sides are reasonable, and some arguments are not. Some against dust collection seem to me to be equivalent to saying that because some people have survived playing Russian roulette, and some people have died brushing their teeth, that brushing your teeth is equally dangerous as Russian roulette. It's not: discussing risk without statistics is pointless.

[Cody Colston]

I got my Oneida cyclone because I was tired of sweeping up the sawdust and wood chips. The planer was what put me over the hump because it produced a mountain of shavings every time I used it.

After installing the cyclone, I noticed that not only did I have very little sawdust and chips to sweep up but everything in the shop stayed much cleaner. There wasn't that layer of fine dust covering everything like there had been ante-cyclone.

The dust still accumulates because there is always going to be free dust in a woodworking shop. It just takes it much longer to build up before I have to open the doors and blow it out with a leaf blower. :)