Phil Thien's Baffle and Bill Pentz

[Randy Klein]

Not trying to start anything but was just wondering if Bill Pentz has ever commented (good or bad) on Phil Thien's baffle design incorporated into a DC.

[Ken Fitzgerald]

I would suggest go to BIll's website and asking him.

[Pete Bradley]

...and lock this thread

[Ken Garlock]

...and lock this thread

Bill Pentz is the de-facto authority on cyclone dust collectors. Bill's collector has, by design, baffles that have been tested by Bill and others to obtain an optimal configuration. From the little I have seen on SMC, the Thien baffle would add nothing to a Pentz cyclone dust collector and would disrupt the air flow within the cyclone.
For a detailed analysis of the Pentz cyclone go to his website.

Pete, a good discussion will help to clarify the differences in the two approaches to dust collection.

[Peter Aeschliman]

I'm sure Bill's approach to pre-separation is superior to the Thien approach, but you're really comparing apples and oranges.

The Thien approach is financially accessible to nearly all woodworkers. It will do an acceptable job with a big enough DC. Pentz's approach is a no holds barred DC approach.

Although Bill Pentz is known for his cyclone design, most of the subject matter on his site cover issues such as impeller size, Motor power, CFM, static pressure, duct size, fittings on the tools, health risks, etc.

I have little doubt that Bill will say his separator is more effective, and I bet Phil Thien would tell you the same. This is like comparing a Honda to a Bentley.

[Curt Harms]

certainly a cyclone is better than a single stage collector. The return on investment on the Thien baffle is better than any shop gadget I can think of though. It can be made from scrap (I did it) or for a very few $ and really helps keep cartridge filters clean. Filters will still get stuff in them, mostly fine dust, but not nearly as much as without the Thien baffle.

[Ken Garlock]

Okay gents, don't get your sandpaper in a knot. I read the initial post as a question regarding the efficacy of integrating the Thien baffle to the Pentz cyclone. Upon reading again, it was not such a request.
I can see where the Thein baffle would work as a first step toward the eventual goal of a cyclone.

That is my story and I'm sticking by it.

[David Hostetler]

Not trying to start anything but was just wondering if Bill Pentz has ever commented (good or bad) on Phil Thien's baffle design incorporated into a DC.

I have not seen any such posts. Bill recommends a neutral vane in his own web site, which is actually somewhat surprising

http://billpentz.com/woodworking/cyc...erInstallation

I have found some of Bills assertions that are in my opinion a bit, uh, excessive... Not wrong per se, but excessive... If you read his work, you pretty much have to come to the conclusion that unless you are using a 5HP ClearVue cyclone you are going to die a horrible death of lung cancer and wood allergies.

I have also seen the end results of the neutral vane, and the end results of the Thien baffle first hand... As far as maintaining air flow by keeping junk out of the filter, the Thien wins hands down, for the obvious reason that it eliminates scrubbing out of the dust bin...

[Randy Klein]

Just to clarify: I wasn't trying to see how a Thien Baffle can be integrated into a cyclone (Bill's design or other).

I'm just doing my research on a DC and it seems like there is a few options:
1. Regular bag (or cartridge) DC
2. #1 modded with a pre-separator based on Phil's baffle
3. #1 with Phil's baffle internal to the DC
4. Stock cyclone
5. Clearvue cyclone

It seems that Bill's research is a few years dated as it pertains to comparing to modern devices. So I was just wondering if the modern cyclones are still just as bad (in Bill's opinion) as when Bill did his initial analysis.

I read that Grizzly had consulted with him at one point and didn't know if the results of that have been incorporated into their current selection.

[Phil Thien]

1. Regular bag (or cartridge) DC
2. #1 modded with a pre-separator based on Phil's baffle
3. #1 with Phil's baffle internal to the DC
4. Stock cyclone
5. Clearvue cyclone

You've done a good job of identifying the choices.

I'll submit that most people make their decision based upon three factors: (1) Cost, (2) Size, and (3) Noise.

So if you have the $$$, the room, and can tolerate the noise, you will typically go with a cyclone.

If you're not flush with cash, have a small shop or low ceilings, or work in a basement where cyclone noise might bother other family members, you will typically go with one of the other options.

Things get complicated if you've already made an investment in DC. If you already have a single-stage w/ cart. filter, well, what is the harm with adding Thien gear to see how it works for you? You can then use that personal experience to decide whether making the additional investment in a cyclone is justified.

In the final analysis, if one has the means and the room for a cyclone (and doesn't care about noise), yet wonders if one of the other choices will be sufficient, I submit that is like asking the ugly girl to the dance when you already know the pretty one wouldn't turn you down.

[David Hostetler]

You've done a good job of identifying the choices.

I'll submit that most people make their decision based upon three factors: (1) Cost, (2) Size, and (3) Noise.

So if you have the $$$, the room, and can tolerate the noise, you will typically go with a cyclone.

If you're not flush with cash, have a small shop or low ceilings, or work in a basement where cyclone noise might bother other family members, you will typically go with one of the other options.

Things get complicated if you've already made an investment in DC. If you already have a single-stage w/ cart. filter, well, what is the harm with adding Thien gear to see how it works for you? You can then use that personal experience to decide whether making the additional investment in a cyclone is justified.

In the final analysis, if one has the means and the room for a cyclone (and doesn't care about noise), yet wonders if one of the other choices will satisfy their needs, I submit that is like asking whether you should ask the ugly girl to the dance when you know the pretty girl would say "yes."

All kidding aside, I agree with the idea that if you have the bucks, and space, and can deal with the noise, then yes, a ClearVue, or similar cyclone is your best bet, and I think you hit it spot on. That pretty girl as it were usually wants the guy that drives the Beemer, looks like Brad Pitt, and bathes in cash. That doesn't describe most of us... My issue with Bill's writings as I have posted here and elsewhere is that he comes off, intentionally or not, giving the reader the impression that if you can't afford to go full blown with a full on cyclone and big ducts that you might as well just not try. All other efforts it seems are wasted time, money, and effort. I fuss about it because I feel Bill is in his zealous efforts to advance knowledge of dust collection, is doing a fair amount of harm in the area by discouraging folks from doing the best they can manage. Even if it is not quite perfect. 85% fine dust collection / abatement is far better than 0% isn't it? If it's not, I would love to know why...

[John Coloccia]

Actually, all that Bill Pentz has done is say IF you want to collect fine dust to the level that your shop air is safe to breather, THEN you must meet these minimal requirements. The other choice is simply wear a mask when you're working in the shop, run an air cleaner and keep a Dylos meter around so you understand the dust dynamics in your shop.

What he doesn't say is "do the best you can and call that safe" because it's not. He says do the best you can, but if you're still not safe, wear a mask. Then he spends an enormous amount of time (and probably money) explaining best practices. The vast majority of the site deals with best practices for duct work, and minimum requirements to collect the harmful, fine dust. Underlying the whole thing is if you can't do that, then you need to wear a mask or you will ingest harmful dust.

I really fail to see what possible controversy is here. It's common sense, and anyone can simply buy a meter (or have an air quality check done) and you can measure it for yourself how effective your dust collection is. There's no mystery or philosophy involved. Just measure it.

The problem with less effective dust collection methods is that many fail to collect nearly 100% of the harmful particles. In that sense, there really is no point to wasting time and money on DC if a safe shop is your goal because the DC is contributing nothing. You'll have a clean shop but you have to make it safe another way, and that's his point.

Bill's a great guy. Just e-mail him and he'll give you all he knows about the baffle. Remember, though, that the goal of the baffle or a cyclone is NOT to make the air safe to breathe, but rather to keep the most stuff our of the filters so that they won't clog as often. I could completely remove my cyclone and plug up the hole, and it would perform just as well as it does now....for about 10 seconds until my filters clogged.

What he'll probably say is that there's nothing wrong with the baffle, and it will reduce the load on your filters, but that it won't help you with dust collection one bit and in fact it might even hurt your airflow just a little bit.

So regardless of the design, if you have well designed hoods, adequate airflow (i.e. lots of horsepower and big pipes) the the exhaust is well filtered, you'll have good dust collection. Filter bags, baffles, cyclones, etc don't matter. Hoods, airflow and filtration are the only things that matter. The rest simply affects how often you need to clean/replace your filters. If it's every 10 seconds, you have problems. I clean mine about once every 6 months. That's what Bill's cyclone design buys me. I can use very expensive and high efficiency filters without worrying about wearing them out every year. If money and convenience were no object, there would be no reason for a cyclone in my shop.

I hope this helps. I happen to think the baffle is probably a good idea. Anything that reduces wear and maintenance, plus adds convenience, is a good idea IMHO.

[mreza Salav]

it is *possible* to get that impression from Bill's site but I think he is trying to say what is the best known method to capture fine dust. In fact, when I was trying to purchase my DC I searched his site and as I couldn't afford a cyclone at the time I decided on a single stage DC. After consulting with Bill himself, he was nice enough to inform me what is the best single stage DC in the price range I was looking for and how to use it to have the most effective way of capturing dust.
Of course, it's not nearly as good as a full blown 5HP cyclone, but you have to live with what you have/can afford at the time.

[Thom Sturgill]

85% fine dust collection / abatement is far better than 0% isn't it? If it's not, I would love to know why...

The 'debate' between Phil's separator and Bill's cyclone is cleanlliness vs health issues. As a security technician, I would say that if you use Phil's separator and are expecting health protection, you have a false sense of security and that can be dangerous. To get the same HEALTH benefit you would need to still wear a respirator.

If all you want is a clean shop, then Phil's separator (especially if coupled with a hanging air filter) will help give you that, and a lower cost and quieter to boot. But don't fool yourself into thinking that you are protecting your lungs.

[Jim O'Dell]

I agree, do as much as you can with the funds available. If you can go the route of the cyclone, that is the best for the collection of the "fine" dust without continually clogging the filters. I think if you talked to Bill, he would tell you to do the best you can, but be sure to wear a respirator. Bill, with his medical problems, has said even with his cyclone, he wears a mask. His problems are severe, and he doesn't take chances. Think of his website as applying for a job. He gives you the best way to do it. In making his case for that, the less than great possibilities don't get discussed. If I was making a pitch to convince someone of something, I'd do the same thing.
I've had the pleasure of trading private messages with Bill over the years. Some where I asked him something, others where he sent me some information in relation to a post I made here about my system install. He's a genuine decent man trying to help others not fall into the health problems he has. Jim.