Bill Pentz and Cyclone Test

[Tim Marks]

No, your statement is not accurate. I have two engineering degrees, and a general education college degree that I never bothered to pickup...

Sorry, my mistake. Which engineering degrees were those and where and what year did you get your diplomas? You should really update your website; you can understand how I got confused when I read the following:

With units and course work ample to get minors in pre-medicine, engineering, biology, chemistry, physics, organic chemistry, philosophy, psychology, and art, UC Davis offered me a certificate in general education. I only needed a few engineering classes for my bioengineering degree but they would not let me back in. Distraught and bitter over the whole experience, I ignored that offer failing to pick up that general degree...

Sadly, there were some technicalities imposed by the Legislature that forced me to go back and take advanced ethnic studies before my BS work would be completed. Without that BS in hand, it turned out that in spite of a 3.9+GPA in my master's courses, I could not legally take credit for them. After years of frustration trying to get the degree I earned, I finally gave up and just claim it.

http://www.billpentz.com/educate.htm

[Chuck Tringo]

Well, as a big DC system of any style is not in my budget right now, ill keep working with the garage door open and my respirator on. I can afford a better fan, i think ill get one of the big industrial style ones as soon as i get back in the shop. I do have a Steel City air cleaner that I run whenever im out there and for about an hour or two longer than I work, and it is posted right before the door, as i hope to catch as much dust as possible before it goes into the house.

[Will Blick]

Bill, thanks for taking the time to answer my questions so thoroughly.... you cleared up several issues.

you wrote...

> I think what makes this most dangerous is understanding that hand sawing less than 7” of ¾” stock creates enough fine dust to cause a typical 2-car garage sized shop to fail and OSHA air quality test,


I have read where you wrote this before, and you are right, this statistic is shocking..... it really demonstrates how much fine dust is created doing the most simple task....wow... I may have a different outlook from this point forward on how many projects I decide to tackle.


What full face powered respirator would you recommend? I have strongly considered the 3m Adflo, what is your thoughts on this respirator? It seems ideal for ww'ing?


As for your comments regarding people bashing you on these forums. IMO, for every person who attacks you senselessly, there is probably 500 people who really appreciate your contributions to the ww community. It's unfortunate more supporters don't post regarding these unwarranted attacks.....its just the nature of forums in general. I find SMC is well moderated, unlike others such as woodnet where the pile-ons are so ridiculous, it borders on insanity. So maybe, its best you pick and choose your forums carefully. Also, thanks for the web site. If you ever decide to publish a book, put me on the list.

[John Stevens]

Bill Pentz wrote: "He explained that hand sawing less than 7” of ¾” stock generates enough fine dust to cause a typical 2-car garage sized shop to fail an OSHA air quality test."

This is not a dig at anyone--not Bill Pentz, not the expert he quoted, and not even OSHA. But it seems to me in comparison to the example given, most people are exposed to fine dust in far greater concentrations on a regular basis. Can you imagine how much fine dust is inhaled by the average person who sweeps, vacuums and dusts the house each week? Anyone who has sifted flour, bailed hay, raked fallen leaves, worked in a greenhouse, emptied trash cans, sat in a tavern, or ridden on unpaved roads has inhaled clouds of fine dust, sometimes for hours on end. And yet almost none of us show any adverse effects from it. I think this shows that comparisons with the OSHA standard are of limited utility in gauging health risks associated with exposure to fine wood dust for otherwise healthy people.

Regards,

John

[Ken Baker]

Bill - I personally want to thank you for the information on your website and the postings I have read on this and other forums. None of the naysayers seem to have their own websites - it's very easy to criticize, but much harder to do something about it. As mentioned above - I'm sure there are countless people who have benefited but don't come forward.

When I got back into woodworking last year I had the means to afford better stuff and I avidly read every page on your site and used it as the baseline for my dust collection system. I bought a clear vue cyclone and am running 6" lines as far as I can. I built a shed oustide to house the unit so I don't have to worry about which filter is best for the return air.

I personally don't care "who invented what - and who gets the credit" - You sir get the credit for compiling all the information into one cohesive website.

If you are ever in Orange County I would be honored for you to visit and critique my shop and offer any suggestions that improve my chances of living a life that is not cut short from microns of dust.

[Bill Pentz]

... What full face powered respirator would you recommend? I have strongly considered the 3m Adflo, what is your thoughts on this respirator? It seems ideal for ww'ing?

Will,

On my Doc's Order's pages you will see I am not a big fan of powered respirators. I really disliked rushing projects because my powered respirator batteries kept dying. Although we have much better batteries today, for most I still think a good 3M model 7500 respirator mask in the right size is plenty. For those who turn, it is nice to have a powered respirator with protective face shield. Many of my wood turner friends swear by the old Racal PAPR units with the belt mounted battery pack, filter, and blower. Those stopped being made when 3M bought up that technology. I see the near identical current 3M models similar to the 3M Adflo can set you back $1000+ dollars. Today you can buy the Trend Airshield, a very similar powered respirator that most like. I use one of the older Racals with a mix of 3M stuff, plus have a Triton.

[Tim Marks]

Thanks Bill. Your webpage update clears up some confusion about your missing degrees.

Looking at your cyclone modification, I guess I missed that you are really advocating a 1D1.64D instead of a 1D2D that others in industry said were most efficient. I bet you got good at cutting up sheetmetal before you came up with that answer.

Since this 1.64D dimension is really based upon making a cyclone that first under a typical ceiling, if someone had unlimited ceiling space or were scaling this design down to a vacuum sized dust collector, would they be better off using the more typical 1D2D or 1D3D design then your design?

Laymens terms: a 1D2D cyclone size related the diameter (D) against the upper body and lower cone. A 1D2D cyclone with an 18" diameter would be 18+36=54". Add a barrel on the bottom and a blower on the top, and you would have to cut a hole in the ceiling.

One of the other critical dimensions is the inlet size. A typical cyclone is specified with a rectangular inlet of D/4 wide and D/2 tall. Since most people run 6" pipe at least, wouldn't it make sense to scale the cyclone off that dimension (if you have room). So that would ,make an inlet 12x6", a diamter of 24", and a cyclone height of 24+40". With your chosen cyclone diameter and the resulting required size of the inlet duct, wouldn't that tend to choke flow?

Bill, have you ever tried to feed back the critical data you found to some of the cyclone experts in the agricultural field (Wang, Parnell)? I have not seen the 1.64 number referenced anywhere else.

[Art Mann]

. . . for most I still think a good 3M model 7500 respirator mask in the right size is plenty.

I noticed from your photo that you have a beard. Well, so do I. I use a similar mask for high risk operations like spraying, sanding and cutting MDF. I was wondering just how much dust makes its way around the mask through the beard.

[Phil Thien]

I noticed from your photo that you have a beard. Well, so do I. I use a similar mask for high risk operations like spraying, sanding and cutting MDF. I was wondering just how much dust makes its way around the mask through the beard.

Depends on the beard. I strongly suggest you upgrade to a 1-micron type. HEPA beards are nice but too scratchy.

[Thom Sturgill]

Bill,
Thank you very much for your work. I have lost family to lung cancer and personally have a heart condition that makes me sensitive to breathing issues. I currently work in a Florida garage and keep the large door open with a fan blowing from behind me and wear a mask (most of the time). I also have a HF DC that I will be buying a Wynn filter for. When I retire in a few years I hope to move back to NC mountains and build a shop there, and if I want to work during the late fall/winter/early spring I will have to close the shop and heat it.

I have seen a lot of comments about the issue of venting outside and heat loss, since the high CFMs required can totally exhaust the air in a small shop in a few minutes requiring considerable make up air. This becomes a major issue in a heated/air conditioned space. I know that air heat recovery ventilators exist, but residential units are sized for much lower CFMs (2-300). Has any work been done on incorporating heat exchangers into dust extraction systems? To what result?

[Eric Haycraft]

I have a small shop in a tucked under (currently unheated) garage. It is hovering around 10 degrees outside now in MN and venting outside or leaving the garage door open doesn't seem like a good option.

Has anyone rigged up a dust collector with an air to air heat exchanger so that they can vent outside and capture most of the heat loss? If so, are there any ways to do it on a budget and is it that much better of an option than venting inside?

Thanks,

Eric

[Phil Thien]

Has anyone rigged up a dust collector with an air to air heat exchanger so that they can vent outside and capture most of the heat loss? If so, are there any ways to do it on a budget and is it that much better of an option than venting inside?

Thanks,

Eric

Oooh. That is a good question that I have wondered about myself. Can't imagine why it wouldn't work.

[Art Mann]

Depends on the beard. I strongly suggest you upgrade to a 1-micron type. HEPA beards are nice but too scratchy.

No chance of that. My beard is the consistency (and appearance) of coarse steel wool.

[Bill Jepson]

Bill, thanks for taking the time to answer my questions so thoroughly.... you cleared up several issues.

you wrote...

> I think what makes this most dangerous is understanding that hand sawing less than 7” of ¾” stock creates enough fine dust to cause a typical 2-car garage sized shop to fail and OSHA air quality test,


I have read where you wrote this before, and you are right, this statistic is shocking..... it really demonstrates how much fine dust is created doing the most simple task....wow... I may have a different outlook from this point forward on how many projects I decide to tackle.


What full face powered respirator would you recommend? I have strongly considered the 3m Adflo, what is your thoughts on this respirator? It seems ideal for ww'ing?


As for your comments regarding people bashing you on these forums. IMO, for every person who attacks you senselessly, there is probably 500 people who really appreciate your contributions to the ww community. It's unfortunate more supporters don't post regarding these unwarranted attacks.....its just the nature of forums in general. I find SMC is well moderated, unlike others such as woodnet where the pile-ons are so ridiculous, it borders on insanity. So maybe, its best you pick and choose your forums carefully. Also, thanks for the web site. If you ever decide to publish a book, put me on the list.

Bill P, Will is correct, few people who are satisfied with your system will comment. Those harping about qualifcations should be spending the money and doing the blasted test themselves then, AND posting their results to be criticized. I believe one of the most CRITICAL items that you have brought to light for the hobbyist woodworker is that the most critical particles to catch are those that can't even be seen by the avrage person. I truly thank you for that. I was aware of these kind of problems having done some automotive painting. In that kind of painting even vapors are dangerous. The auto paint industry goes so far as to recomend an external air source. Either forced air or the equivilent of a scuba tank!
Are different people effected differently, well YES. Are there different levels of exposure that will effect people adversly, of course. The fact that started Mr. Pentz campaign for awareness may have been his own unfortunate sensitivity. The vital point he brings though is that many of the problems that arise from particulate contamination are cumulative. Once you have been sensitized YOU ARE DONE. There is no back or escape key on your lungs. If you are like the little 102 year old guy we see on the news that lived to that ripe old age while drinking and smoking every day, fine. Just remember not eveybody is so lucky. I don't know Bill Pentz but I have visited his web site, which I consider well reasoned and accurate. Remember he posted the plans to his version of the cyclone DC FOR FREE!
The attitude of the people sniping at him is foolish at best. He isn't trying to legislate that you have to use his system, just informing you as to the dangers inherent in what we do.
I really can't understand the resistance to advancement in shop safety. I didn't like the Saw Stop legislative efforts, but to naysay the PRODUCT doesn't make sense. It is a excellent idea that has already saved a lot of peoples fingers. I believe Mr. Pentz has, do to his own unfortunate circumstances, been forced into doing a better job of dust collection. The fact that he has offered the info he's learned FREE to the rest of us deserves a medal, not critics. My $0.02.
Bill Jepson

[Will Blick]

Bill J, EXCELLENT post!!!! I could have not said this better myself, thank you...

Bill P, I understand your issue regarding battery life for powered respirator, but the adflo can run 8 hrs, more than I would use it for in a day.... and it offers both organic vapor cartridges as well as dust cartridges which can be piggy backed, specially for cutting MDF. Since I want a protection from finishing and dust, and I don't have a beard...... do you see the benefit better? The Trend does not offer organic filters, so its dust control only.

The other benefit of a powered respirator is, you don't have to slam the respirator to you face to create a super tight seal like you do a manual respirator (to prevent leaks). The pressure on your face is annoying, and many of us suffer from "scuba mask headaches" from the continuous pressure on our face.

I do use a half face manual respirator. My other big problem with them is, its hard to wear safety glasses, as the nose seals come up so high, there is no place to sit the glasses on your nose.

Any thoughts?