BillPentz.com :: Dust Collection Research :: Doctor's Orders

Doctor's Orders

Table of Contents

(click on topic to go there)
  1. Foreword
  2. Cleanup
  3. Woodworking Environment
  4. Dust Mask
  5. Powered Respirator
  6. Dust Fan
  7. Exhaust Fan
  8. Exhausting Outside
  9. Carbon Monoxide Monitor
  10. Air Filtering
    1. Shop Vacuum Filter Upgrade
    2. Dust Collectors & Cyclones
    3. Air Cleaner
  11. Downdraft Table
  12. PortableHood
  13. Clothing


  1. Foreword
  2. This information will make the most sense if you start by reading the Introduction then the Dust Collection Basics page followed by the Medical Risks pages then this Doctor's Orders page.

    My doctor said he knew quite a few things that would help with the fine dust problem, but left the biggest issue up to me which was how to collect the fine dust as it is made then get rid of this dust. Without doing this, all the other dust collection efforts are not going to be very effective. He laid out many options and over the years has added more, plus approved options that were suggested to me by other woodworkers. Although countless others, especially my medical air quality inspector added considerable advice, I still call this web page "Doc's Orders" because he laid out most of this information.

  3. Cleanup
  4. Because I was already sensitized he recommended immediately having someone else vacuum everything in my home with a strong vacuum that either exhausts outside or uses a HEPA filter. To clean my shop he recommended I wait for a breezy day then have someone else put on a mask, seal off the house, open the big garage doors and side door to my garage based shop, put a big exhaust fan in the doorway that worked with the wind direction and then thoroughly blow out my shop with my air compressor going over and over things until seeing no more dust. After the shop was blown out leave all open and let the big exhaust fan run for at least four hours. After that fan cleared the airborne dust, close all down and let whatever dust was left settle for at least a day. Then again have someone else use a powerful vacuum to clean all while either exhausting outside or through a HEPA filter.

  5. Woodworking Environment
  6. My respiratory doctor used to tell his woodworker patients to always wear a good fine filtered mask and always use a large exhaust fan to clear out the air from our work areas when making fine dust. Years later after working with me on this dust collection site my doctor changed this recommendation. He recognized that letting fine dust loose in our woodworking environments is unacceptable because even with a good exhaust fan it takes months to years for this fine dust to break down and dissipate so every time we use our shop we get exposed even when not making fine dust. Because fine dust rapidly spreads in any shared air and is easily carried on our hair, skin and clothes, it often contaminates not only our shops, but our vehicles and all areas we visit which will continue to cause harm to us, all close to us, and even our pets. He now tells his patients that safe woodworking requires us to control the fine dust as it is made, capture it at the source, then immediately get rid of it so it never gets into our shop air! When we cannot keep from spraying the fine dust into our woodworking environment, we must take our work outside with our masks on.

  7. Dust Mask
  8. My respiratory doctor says every woodworker needs to own, use and properly maintain a good respirator often called a dust mask. Respirator masks and supplies are available in almost every large hardware store. He recommends strongly against use of the less expensive readily available disposable paper masks because even with good filtering, they leak badly exposing us to far too much fine dust. He instead says we need to use a good quality fitted respirator mask that meets the NIOSH safety standards. It should have a good silicon-rubber airtight fit with two changeable cartridge filters. Filters should be readily available to also protect against the various solvents, fiberglass resins, epoxies, and other chemicals we use while doing woodworking. We must regularly wipe our masks out with a non-alcohol pad to keep our masks clean and change the cartridge filters when needed. Activated charcoal filters and many other types of mask filters lose effectiveness when exposed to air whether we are wearing them or not, so he recommends storing our masks in a Ziploc airtight bag with most of the air sucked out to maximize filter life. There is a wealth of information on masks, testing for leaks, choices of filters, filter life, etc. I used the Google Search Engine searching on "dust mask" and found myself overwhelmed with more sources and information than I wanted to read.

    With my asthma and lingering lung problems, he told me to seriously read over the information and consider buying an upper end Powered Air Purifying Respirator (PAPR) mask such as those offered by Enviro Safety Products. My follow-up bought an expensive powered respirator type mask recommended by magazine articles and by many on the various wood working forums. I hated my powered respirator mask, probably due to bias from over 4,000 hours of flying with a good fitting comfortable oxygen mask. The powered respirator mask was miserably uncomfortable. I disliked looking through a plastic face shield that quickly scratched, disliked the shield fogging a little with each breath, disliked getting its hose and cord tangled as I worked, and hated it always leaving me in a rush to get things done before the batteries ran out. I paid over $100 for my respirator’s unique battery pack which contained about $20 of poor quality Ni-CAD batteries good for only a few minutes use. Even after buying a second of these ridiculously expensive spare battery packs I found myself constantly rushing and messing up portions of my work. I do woodworking as a hobby to relax and wearing that mask was anything but relaxing. I gave it away and replaced it with a top quality 3M 6000 series regular respirator mask. I made up my mind after buying a second battery pack that if I bought another powered respirator, it would be a 3M simply because parts, filters, face shields, shield protectors, batteries, etc. are affordable and readily available. Today I would probably buy the newer 3M 7500 series mask with a dozen organic filters, P-series particulate filters, and box of cleaning pads.

  9. Powered Respirator
  10. Unfortunately, my challenges with powered respirators were not over. Following additional respiratory problems with repeated bouts of pneumonia, in 2006 my doctor gave me a choice of permanently giving up woodworking or always using a powered respirator mask. A Powered Air Purifying Respirator (PAPR) uses a blower to pull air through a course then fine filter then blow it into a face area so we constantly only have clean filtered air to breathe. I frequently have a full beard, so whatever I got had to have enough positive pressure to ensure to overcome the leaks caused by my beard. Moreover, although I don't make any claims as a metal worker, I do have a fairly large complement of metal working tools and nice welder, so I also wanted something that could do double duty if possible for my welding.

    I did a lot of homework and talked to many woodworkers who have long used the different powered respirator masks. The mask that my wood turner friends that often work the most toxic woods most liked was the old Racal which is no longer made, but we can still get parts for through 3M. The most popular among more recent purchasers was the Triton which can be purchased at considerable savings from Amazon.com. The one that got the highest reviews next to the Racal was the 3M powered respirator which was not that big of a surprise as 3M bought Racal. The other advantage of that 3M unit was I had a couple of interesting options. It had a different face mask that allows using it for welding. 3M also offers a belt type filter system that will let this mask be powered by a good air compressor rather than having to put up with the battery packs. Unlike the earlier Racal or current Triton the 3M powered respirator that I needed with an extra belt battery pack was $900+. I bought the full Triton system from Amazon. That mask is alright, but I am not in love with it. One of my wood turner friends continued to push me to look for the older Racal powered respirators. He said they clean up fine and I could replace most of the parts new from 3M.

    I finally stumbled on a dealer who was closing out his new but old stock Racal inventory on eBay and put in a bid for the works. While waiting for the results of that bid, I also came across another interesting deal for a set of the 3M powered respirator masks, one for welding and the other for painting. About all the seller knew about these masks was they were my size. Because they knew nothing of these masks and had no idea if they even worked, they priced them with a ridiculously low "Buy-It-Now" price. I bought them immediately expecting that even if this was junk I could throw them away and loose little. Meanwhile I had the high successful bid and bought the works from that Racal close out. What finally arrived was one new and one used Racal helmet, two new masks with multiple clear plastic face shields, a box of face shield protectors, two extra battery pack/blowers, plus a box of the face seals that keep that mask comfortable to wear and still have a good enough seal. To my surprise there were enough parts to give me two full separate powered respirator masks. Even those new battery packs were too old so I took them all to my local Batteries Plus outlet store. They replaced those tired Ni-Cad batteries with high end Sanyo Ni-MiH cells that last far longer. Meanwhile the 3M masks arrived and I was blown away. Apparently these masks were bought new and then never even opened, sat around for a few years, then were sold when they did some house cleaning. The welder mask came with both the 3M belt pack plus the compressor setup, while the paint setup came with a pair of the belt packs. The 3M batteries were also shot, but I knew how to fix that. After taking care of a friend I was left with the Racal that my friends like plus both the 3M paint and 3M welding powered respirator masks. Now all I need is to get well enough to use these things.

    So enough of my bragging, what would I recommend to somebody today? A 3M 7500 series non-powered mask with dual cartridge filters, prefilters, and organic vapor cartridges unless you are a turner or are sensitive to dust. Then a Powered Air Purifying Respirator (PAPR) with face shield is better. I most like the Trend Airshield Units. The Trend AirShield Pro pictured above is more costly but a near exact twin to my Racal that so many swear by. My more current turner friends say these Trend Airshield PAPR masks are costly but worth it.

  11. Dust Fan
  12. My respiratory doctor said even when working outside, whenever I made fine dust that was not being immediately captured I needed to use a fan. He recommended using a good heavy duty stand mounted oscillating fan with the oscillation feature turned off. This fan must be set to blow the dust away from me as I worked to keep me from breathing it and to help keep my clothing clean. My respiratory doctor also recommended I use this good sized fan in the back doorway of my shop with the garage door open a little whenever making fine dust to keep that dust from building in my shop. I have to sometimes make the fan in the doorway blow outward and other times blow in depending upon the local wind direction. In the few instances where I mess up and fill my shop with fine dust he recommended I use that fan on high with all doors open wide while also running my air cleaner and cyclone with fine filters, then after all settles vacuum all with my HEPA filtered vacuum.

  13. Exhaust Fan
  14. A few of my friends also recommend using in every shop that is attached to our homes an exhaust fan wired to turn on whenever we turn on the lights. If we have all doors and windows closed and run that exhaust fan to the outside it will create a negative pressure. This fan does not have to exhaust any air. A small bathroom exhaust fan creates enough negative pressure to keep a blast of dust filled air from contaminating our homes when we open a connecting door between our shop and home.

  15. Exhausting Outside
  16. My respiratory doctor says ideally we would all do just like commercial shops and just blow the finest dust away outside. Although most small shop woodworkers should exhaust their shop air outside, most do not. He said there are many excuses and reasons to vent indoors, the main one being that it is easier. Venting our dust collectors and cyclones indoors even with fine filters causes our shops to build up dangerously large amounts of fine dust. Venting inside also increases our risks as most dust collectors and even cyclones come with collection bins that are not fire proof. There are a few good reasons to not exhaust outside and many better reasons to do so.

    1. In some areas like mine venting outside is illegal. Although this is what I heard from my County building inspector's office, it turns out that it is illegal only if I am a commercial firm, so is not enforced for small shops. This is one of those things that upset me considerably because I tried to do all right, got bad advice and spent a lot of time and money that really was not necessary.

    2. The noise can upset neighbors. Adding a little sound proofing either around our dust collection equipment or storage shed, plus using a good muffler, homemade or commercial will address most of the noise issue.

    3. Too many small shop owners foolishly worry about blowing the heated air out of their shops when commercial firms have shown that doing so really is not as expensive as trying to filter the air. Large commercial shops with huge blowers that turn over the entire air volume many times every hour have known for years a good radiant heater will leave us feeling little discomfort unless it is below freezing outside.

    4. Our hobbyist dust collectors and cyclones are built for indoor use. Repair is as easy as providing their own shed or covering to place our dust collectors and cyclones outside. Many simply choose to keep their cyclones inside and vent outside.

    5. Also, a good many of the woods used in woodworking today can kill our landscaping plants, and can harm our pets and children when they play outside. Repair is fairly simple, use a cyclone separator to remove the heavier sawdust and chips. The remaining fine dust will dissipate in the outdoor air without causing problems.

    6. Finally, Unless we provide a way for makeup air to enter our shop, blowing the air outside can suck deadly carbon monoxide backward through our vents. Most need to just open a door or window and they the risks of pulling the carbon monoxide out of our fired appliances vanishes.

  17. Carbon Monoxide Monitor
  18. My respiratory doctor and many safety organizations warn our dust fans, exhaust fans, dust collectors, and cyclones can pull deadly carbon monoxide backward through the vents from our gas water heaters, heaters, fireplaces, furnaces, and other fired appliances. I found my shop exhaust fan and dust collection blower pulled carbon monoxide from my attached home furnace. My doctor strongly recommends every small shop woodworker install good quality carbon monoxide detectors in their home and shop to immediately know if we have a problem.

  19. Air Filtering
  20. My respiratory doctor recommends we buy filters with enough surface area and ample fine filtering. Unfortunately, most small shop filters provided with dust collectors, cyclones, air cleaners, and even shop vacuums are too open so pass most of the unhealthiest invisible dust plus have too little surface area so clog constantly requiring frequent cleaning and quickly wear out.

    1. Shop Vacuum Filter Upgrade
    2. My respiratory doctor said to immediately change my vacuum filter from their paper and cloth bags to HEPA air filters. Luckily both of my vacuums are name brand units for which good quality HEPA fine filters are readily available. Early on the cost of one of these fine filters for a shop vacuum came close to the cost for a smaller vacuum. Now that there is far more interest, prices have fallen far below the somewhat painful $30 each I had to pay.

    3. Dust Collector & Cyclones
    4. My respiratory doctor remains pretty strongly against upgrading to finer filters on our dust collectors and cyclones because even fine filters work poorly. The medical air quality testing he has seen show regardless of vendor advertising claims almost all small shop cyclone and dust collector fine bag and cartridge filters freely pass the finest unhealthiest dust. This at best creates a false sense of security because these so called fine filters get rid of the visible dust while allowing the finest unhealthiest invisible dust to just keep building. He instead recommends venting these units outside into standard open 30-micron filters and letting the fine dust blow away into the outside air. He said venting outside also helps get rid of the fugitive dust that escapes collection from these too open filters, dust collectors and cyclones that move too little air for good fine dust collection and tool hoods that allow the fine dust to spray all over.

      I thought I could do air filtering by just letting my cyclone or dust collector run as both had upgraded commercial finer filters. An air engineer friend said that AAF had done extensive testing and found both dust collectors and cyclones make poor air cleaners and their use as air cleaners can be expensive. An air cleaner stirs the whole volume of air in a room. Without that stirring, much of the fine dust will be missed. Unless you setup the air coming out of your filters to blow in a wide stream at close to ceiling height, the air simply creates a narrow racetrack between the open gate and your filters without doing a good job of cleaning the rest of the air. Moreover, a good air cleaner uses a small motor. Running the huge blower motor for the roughly four hours it would take to clean my shop air could create some costly electric bills.

    5. Air Cleaner
    6. My respiratory doctor says he likes and regularly uses his air cleaner but does not rely on it for anything except keeping his finishes from being spoiled with dust contamination. He explained that it takes a typical small shop air cleaner four to six hours to clear the larger airborne dust particles, but most of these come with such open filters they never really do clear the finest unhealthiest dust. He also recommends against trying to upgrade these units with finer filters as most don’t have the air pressure to work against the finer filters as these filters become dirty. Plus upgrading to finer filters makes for a constant cleaning chore and cleaning quickly wears out the fine filters.

      He said the magazines rated Jet, Delta, JDS, and Penn State all pretty close, but he bought a Jet for himself because he likes Jet tools. In looking at many woodworker posts and some magazine reviews, it appears that he did pick one of the best. He now says we either capture the fine dust at the source as it is made or work outside.

  21. Downdraft Table
  22. My respiratory doctor next told me to go buy or build a good quality down draft table and always use it when sanding. I looked at him kind of funny because he has been bugging me for years for a set of plans for the down draft table I built ages ago. We both have long known that there are no good affordable hobbyist downdraft tables. I teased him back saying he was the one who made the big bucks. After looking suitably hurt, he smiled and said if I built another, he could have my old downdraft table and I would get a new one. The projects area of my index gives directions on how to size and build your own downdraft table.

  23. Portable Hood
  24. Years after putting up these web pages my respiratory doctor now recommends every woodworker have and use a good portable hood connected to our dust collector. Too many large tools, smaller power tools, and even hand operations generate lots of fine dust. Often even a downdraft table is not enough to provide good fine dust collection unless we also use a portable dust collection hood placed right next to the dust source. He recommends buying or building a stand that supports this hood and permits positioning it right next to our woodworking operations. I found having both a stand and gluing a few powerful rare earth neodymium magnets to my hood lets me cover almost any need firmly holding the hood right where it is needed without slipping.

  25. Clothing
  26. My doctor also reminded me to not only wear my apron, but also when making fine dust to wear a cap, light jump suit, and bandanna that I take off before going into my home. This keeps the fine dust from being tracked all over. He also recommends wearing wear gloves and good skin protective clothing when working with the more toxic woods.

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