Thread: Why Extractor efficiency matters

Digesting and thinking about this data. From reading your most valuable contributions round' here Bob, I'm now on a mission to improve my dust collection setup. Thank you.

Not sure if you've seen this Bob however do you read woodgears.ca? He's just built his own small dust collector and a few experiments on it during the build. Interesting reading. There is also an interesting email exchange between him and Phil Thien at then end.

Small Dust Collector Build (woodgears.ca/dust_collector/)

Originally Posted by sjt

Not sure if you've seen this Bob however do you read woodgears.ca? He's just built his own small dust collector and a few experiments on it during the build. Interesting reading. There is also an interesting email exchange between him and Phil Thien at then end.

Small Dust Collector Build (woodgears.ca/dust_collector/)

That guy had a very limited understanding of dust.
Like a lot of beginners he relies on eyesight to see the dust, and his ducting, impeller and motors are just way too small for wood dust.
He does eventually work out that his small cyclone adds a significant amount of back pressure to his system - another reason why small cyclones should not be used on small DCs.
Best not to ask me what I think about trash can separators.

A few weeks ago I decided to improve my dust extraction ... thought it would be pretty simple.

Then I started some research. Started on this site and was quickly guided to Bill Pentz's site. Soon figured out that BobL was our local expert, and started to read his posts, as well as some general research. Good dust extraction and healthy workshop air turns out to be a large and complex subject. Folks like me benefit greatly from having someone competent to guide them and to speed up their learning.

To cut a long story short, I'd like to thank Bob, not only for all the advice he has given me, but also for the unselfish way he contributes as much as he can to everyone. This latest thread is but one more reason for many of us to be grateful for his expertise and his contribution.

Thanks Bob! Thanks to your guidance my new system will definitely be vented outside.

Thanks JS. Something to bear in mind is, if I was an expert, why would I be doing all these experiments?

Bob,

I am a consultant, and I work with experts in several fields. One mark of a real expert is that they never stop experimenting and learning ... never. An old axiom in science is, "The empirical evidence is never complete". We never know everything. There is always something to learn. Some folks learn enough to get by and stop there. Real experts never stop experimenting, learning and improving their operation.

Recently I was working at a metallurgical plant that has been operating for many years. We are still running trials ... still collecting and analysing data ... still learning about how this particular plant operates.

When I was a kid my father and grandfather taught me two things to look for when trying to determine whether a particular bloke was a Top Gun. One was that he never stopped experimenting and learning. The other was that he likely made even difficult work look easy.

They were right.

Originally Posted by John Samuel

. . . . . When I was a kid my father and grandfather taught me two things to look for when trying to determine whether a particular bloke was a Top Gun. One was that he never stopped experimenting and learning. The other was that he likely made even difficult work look easy.

OK, seeing as I still struggle to do easy stuff that rules me out

Why do I doubt that?

There has been a lot of discussion about dust extraction over the years, and a couple of periods of "vigour" in both discussion, construction and products come to market.

Of late the who dust issue seems to have gone on the back burner.

Quite a few years ago there was a fluury of activity in cyclone building on this forum, when I cant remember who, introduced us to the work of Bill Pentz... the well known acedemic, athsmatic and part time wood worker.

Bill's work revolves on the premiss of improve dust extraction or give up woodworking, because of his alergies.

Bill's site is now up under his own name Bill's Personal Pages - Home Page

worth a read for anybody interested.

The issue with dust is that the experts set..what some believe to be unreasonable goals for dust in the workplace and the majority of workplaces are nowhere near close.

The majority workplaces AND home workshops are sooo obviously unhealthy, discussing the officially recommended dust levels is completly pointless.
Just making some sort of reasonable effort would be a quantam improvement in most cases.

The bottom line is that any filtraton system that is not incredibly expensive AND discharges inside the workshop will not be effective enough to meet good health expectations.

So the single best and most effective thing is to put ya dust extractor outside.

As for recirculating workshop dust filters......there was a big arguemnt about those a while back, and the considered opinions was that they did not have fine enough filters and their operation actually kept dust sustended in the air longer in some situations.

cheers

Originally Posted by soundman

.
.
The issue with dust is that the experts set..what some believe to be unreasonable goals for dust in the workplace and the majority of workplaces are nowhere near close.

The majority workplaces AND home workshops are sooo obviously unhealthy, discussing the officially recommended dust levels is completly pointless.

So on what other basis do you suggest discussions on dust should take place?
How about a "mystic flat earth basis"?
Sound levels could also be discussed by ear, hardness using our teeth, and we could all go back to using our own feet for length measurements.

My experiments so far have show that putting the DC outside is only half the battle.
As well as the fact that not everyone can vent their DC outside, the issue about making sure the dust is collected at source is proving to be more significant than I first thought.

It is completly pointless discussing dust in any scientificaly measured way, because appart from a very few ( I include OHS professionals) have the means of measuring dust with instruments or any other metered way.

We should be discussing dust from the point of view of reduction at avery practical point.

Because, in the majority of cases, even when every practical measure is taken, the level of dust considered by the OHS gurus as "zero harm" will not be achieved......not even close.

cheers

Originally Posted by soundman

It is completly pointless discussing dust in any scientificaly measured way, because appart from a very few ( I include OHS professionals) have the means of measuring dust with instruments or any other metered way.

We should be discussing dust from the point of view of reduction at avery practical point.

Because, in the majority of cases, even when every practical measure is taken, the level of dust considered by the OHS gurus as "zero harm" will not be achieved......not even close.

cheers

A very good point Soundman. It's left me wondering what is the acceptable setup for dust extraction? If anyone is like me, a $2000 setup is too expensive at this moment in time but compared to my health, can I afford not to? What is the middle ground here in terms of staying healthy whilst enjoying your hobby?

Actually you can measure the dust in a shop or your home for that matter with a particle counter that is close to the accuracy of the bug bucks ones the professionals use starting for about US$200. Then at least you can actually see if your reduction strategy is working as you make each change. While some will argue that the money would be better spent on a better dusty and only reluctantly do more if they sneeze a few dirty snotties into their sleeve. I believe having some basic data as a starting point and comparing it to the data after each fix is made will help to better every small shop, They would also allow everyone to compare their version with the results of others. If woodworking clubs bought them then their members could borrow them in the same way they do with books and videos in their libraries.

Air Quality Monitor $199
I don't work for these guys so I don't benefit if you get one and save your lungs.

Pete

Originally Posted by soundman

We should be discussing dust from the point of view of reduction at avery practical point.

I agree 100% with this but how do you know if you have reduced it.
95% of people use their eyes, in the same way as they use their ears to gauge a sound reduction, and you should know how accurate that is.

Unless a topic is discussed quantitatively it's just hearsay and gossip - nothing less.