Would like advice on dust collection

[Doug Garson]

Interesting, Glenn. I've never thought of the 3M respirator blocking peripheral vision.

I don't want to go on a rant regarding people wearing N95 masks poorly. This is from a mask wearing professional (I'm a retired cardiothoracic anesthesiologist. Was a normal day for me wearing a mask for 11-18 hours straight). I think it's far easier and certainly more comfortable wearing a P100 respirator with a valve for woodworking as opposed to a N95 mask. And there are so many counterfeit masks. Ouch. The vast majority of people wear N95 masks incorrectly, and certainly never have fit tests.

End of rant.

OK, how do you wear a N95 incorrectly? Maybe some of us are doing it without knowing.

[Alan Lightstone]

OK, how do you wear a N95 incorrectly? Maybe some of us are doing it without knowing.

Ok. I'll provide a few links, but my concern is that this will violate the No Covid link policy of the site. My comments just are in regard to woodworking and preventing inhalation of sawdust/wood particles.

These masks have been in use for many years. In medicine we typically only used them for PPE when we wanted to prevent inhalation of really nasty agents. Orthopedic surgeons wear PAPR outfits when performing joint replacements. I've worn them a few times. Not easy at all. To my surprise, I also learned that N95 masks were used by woodworkers. They used to be quite inexpensive. But over the past few years have gone up significantly in cost, although now that is dropping. Many counterfeit N95 masks were produced for monetary reasons. So there's that.

In medicine, at least for operating room staff (nurses, physicians such as anesthesiologists and surgeons) would get fit tested by hospitals to ensure that we were wearing these masks correctly. And many still didn't.

Here's a few links regarding the fit testing:

https://www.ahrq.gov/sites/default/f...it-testing.pdf

Facial hair interferes with good mask fit. So beards are out with them.

Here's OSHA's web site regarding fit testing:
https://www.osha.gov/video/respirato...st%20annually.

And their video:
https://www.osha.gov/video/respirato...on/fit-testing

Real bottom line is that they are pretty uncomfortable to wear correctly for extended periods of time. Plus they are considered one-time use masks.

I have an ample supply of these in the house, and wore them in public over the past few years in appropriate (read risky) locations. And am very accustomed to wearing them in medical settings when needed. And have been fit tested for them. That being said, I'm never considered wearing one in my workshop. The 3M P100 mask I wear (or with the organic cartridge when needed - and there are certainly other excellent choices, like the one Glenn mentioned above) is pretty comfortable for extended wear (I usually forget I have it on. Only putting on and taking off glasses with the respirator and good ear muffs is annoying.)

One quick test, is that if your glasses fog up when wearing them, it is not fit properly. My glasses never fog up with my respirator on.

I hope this helps. I've measured particle counts with a variety of air filters with my wide-belt sander and years ago with my Jet 16-32 drum sander. Even with good dust collection they spew out lots of small, bad to breathe in particles. That's the bottom line for the OP.

[Aaron Inami]

In my experience with just sanding, I have found that the "real" 3M N95 masks that you can get at Home Depot are pretty good. These "real" N95 masks have two strong bands that wrap around the back of your head and hold the mask very tightly to your face. Also, the metal support needs to be bent properly to conform around your nose. They are certainly not cheap (compared to the typical Amazon masks):

https://www.homedepot.com/p/3M-8210-...0-DC/309801231

https://www.homedepot.com/p/3M-8511-...C-PS/203225611

These are certainly not cheap. The cheap fake N95 masks are nothing like this. There have been a lot of what we call KN95 masks (named based on Korea masks). These have bands that fit around your ears and are mostly are made more for comfort. They are a step up from the basic cheap nurses masks, but these are not "real N95" masks.

While the real N95 can be used for sanding, none of these can be used if you have oil-based finish (like polyurethane). You need proper P100 respirators for this:

https://www.amazon.com/3M-Paint-Proj...dp/B00004Z4EB/

[Chris Parks]

Alan Lightstone's posts in this thread should be a sticky, dust kills and as posted in this thread elsewhere can cause lifelong health problems as well.

Alan, can I copy and paste your posts to another forum to get them made a sticky in that forum? I will also attribute them to you as well if you are happy for me to copy them.

[Chris Parks]

While the real N95 can be used for sanding, none of these can be used if you have oil-based finish (like polyurethane). You need proper P100 respirators for this:

https://www.amazon.com/3M-Paint-Proj...dp/B00004Z4EB/

Aaron, can you expand on this point, is it the fumes of the oil based poly's or the dust caused by sanding oil based poly's.

[Alan Lightstone]

Alan Lightstone's posts in this thread should be a sticky, dust kills and as posted in this thread elsewhere can cause lifelong health problems as well.

Alan, can I copy and paste your posts to another forum to get them made a sticky in that forum? I will also attribute them to you as well if you are happy for me to copy them.

Feel free. Glad to help.

[Alan Lightstone]

In my experience with just sanding, I have found that the "real" 3M N95 masks that you can get at Home Depot are pretty good. These "real" N95 masks have two strong bands that wrap around the back of your head and hold the mask very tightly to your face. Also, the metal support needs to be bent properly to conform around your nose. They are certainly not cheap (compared to the typical Amazon masks):

https://www.homedepot.com/p/3M-8210-...0-DC/309801231

https://www.homedepot.com/p/3M-8511-...C-PS/203225611

These are certainly not cheap. The cheap fake N95 masks are nothing like this. There have been a lot of what we call KN95 masks (named based on Korea masks). These have bands that fit around your ears and are mostly are made more for comfort. They are a step up from the basic cheap nurses masks, but these are not "real N95" masks.

While the real N95 can be used for sanding, none of these can be used if you have oil-based finish (like polyurethane). You need proper P100 respirators for this:

https://www.amazon.com/3M-Paint-Proj...dp/B00004Z4EB/

I shook my head at the beginning of the pandemic seeing "N95" masks with ear loops. I had never seen them before in a hospital setting, and the first time I put one on I realized why. While they clearly are more comfortable, they just fit poorly because they are so loose. I don't think they are remotely really able to filter to that level. The entire efficacy of the mask relies on all of its parts working together correctly, not just filter material that is supposed to be up to snuf (poor pun). If you are breathing around the mask, the mask isn't benefitting you. I don't believe ear loop masks can really be N95 in true function. And 0.5 micron dust is terrible to inhale as it goes deeply into your lungs. It's what you really want to filter effectively.

The physics of human ventilation are interesting (at least to an anesthesiologist who needs to understand them in detail), and flow occurs at a far greater rate than people realize. Quick respiratory physiology lesson. A typical human (lets say 70kg) inhales a normal tidal volume of air (about lets say 10ml/kg or 700ml) in about 1 second. They do this about 10-12 times per minute. 700ml of air inspired in 1-1.5 seconds is a flow rate of 28-42 liters/minute. Lets call it 30 L/min. If a mask has a tight seal, it has be be able to have air pass through it at that rapid a rate. That's not easy. The more substantial the filtration, the more the resistance to flow, and the harder that becomes. So what happens then? You simply wind up breathing around the mask. No filtration of that air whatsoever. So it's a constant battle to breathe through the filtration medium without breathing around it via the path of least resistance. Any gap and you will substantially breathe through the gap. It's just physics.

Don't get me started on heart-lung machines and cardiopulmonary bypass. Then things really get complicated.

[Aaron Inami]

Aaron, can you expand on this point, is it the fumes of the oil based poly's or the dust caused by sanding oil based poly's.

It's pretty much the fumes. Aerosalized oil fumes are extremely tiny particles and will pass right through those N95 masks. You definitely do not want to be breathing this stuff. Essentially, if you can smell the fumes then the mask is not doing it's job. Once the oil-based polyurethane has dried, the sanding of the poly just creates dust. Using N95 masks are just fine with this poly dust (basically like wood dust). Though, I have never felt like I needed a mask when doing the "light sanding" of poly between coats.

Oh, I will say that the dual-filter respirators "breathe" very easily. The N95 masks are a bit hard to breathe through because of the seal and filter material.

[Larry Frank]

Lots of interesting comments.

Before I retired, I was working in an area with hazardous dust. We were required to wear N100 masks. They had ear loops to hold in place. We also went thru required training and were tested to make certain they sealed completely. I did not enjoy wearing a mask in a hot work environment.

[Alan Lightstone]

A good start would be to buy an air quality monitor, perhaps something like this which I have. https://www.amazon.ca/Quality-Detect...f-fa04f1ca0da8
It may not be the most accurate but it gives you a reasonable idea where you are at so you can take appropriate action. While collection at source is considered the best approach a shop made air cleaner using a box fan and furnace filters can be another good inexpensive first step. I have one in my 2 car garage shop and see significant improvement in air quality when I turn it on.

Doug's advice above, is very good too. I'm a huge believer in air quality meters and wearing a quality respirator until your particle count goes below what is ambient for you on a typical day. That's my approach. I'd love to hear what others think is appropriate. Of course that depends where you live. This is a photo I took in Beijing on a typical weekday. Imagine breathing this every day. I can't imagine the particle count.
China-414.jpg

This is a link to a thread from two years ago where we went into this in great detail, including a lot of testing of various filters, air cleaners, etc... Also showed my duct taped cheap air filter which is still extremely effective (taken from an Ask This Old House episode, and far cheaper than the typical commercial ones.
https://sawmillcreek.org/showthread....tion-is-Better

Moderators: We really should make that thread a sticky. Lots of good information for our members there. Merging these two would be better still.

Oh, and an addition. Here's 3M's info on fit testing of respirators. Also lots of good info here from a quality manufacturer of masks:
https://www.3m.com/3M/en_US/respirat...n/fit-testing/

Of course, their qualitative fit test kit costs 10 times what their half-face respirator does, so these kits are really made for employers.

If you kids want to try this at home, here's a useful link from a pulmonary toxicologist who describes how to do this yourself in your workshop with saccharin and bitrex (bitters). Still pretty elaborate. You might just want to try to simplify that with aerosolized saccharin. And somehow putting a plastic bag over your face seems so wrong.
https://www.youtube.com/watch?v=FxpVsm3OhLY

[Matt Lau]

update: just got a Delta 50-760 off craigslist.

Planning on walking Wynn tomorrow for a Merv 15 filter.

As for n95 masks, those earloop ones aren't very good. I like the 3m 9205+ masks, and can get them through my office.

[Matt Lau]

Also, any thoughts on the resin super dust deputy vs the steel one?

[Aaron Inami]

Also, any thoughts on the resin super dust deputy vs the steel one?

I would say get the largest one that fits yours scenario. The steel dust deputy is actually smaller than the XL 6 dust deputy. The steel model has a 5" inlet, but the XL model has a 6" inlet. I would go for the XL model if you can get it to fit within your Delta 50-760 frame. The XL model is 37.5" tall and the steel model is 26.5" tall. The XL model would not restrict CFM as much since it has a larger inlet. This is critical when you attach dust collection to things like drum sanders.

[Ron Selzer]

Also, any thoughts on the resin super dust deputy vs the steel one?

No way is that dust collector powerful enough to work with the resin super dust deputy. Been there done that, flat out failure.
Ron

[Michael Burnside]

Also, any thoughts on the resin super dust deputy vs the steel one?

Dust deputy 4/5 is all you need for that DC. Too big and you’ll severely weaken the CFM. My first setup was a Laguna of similar size and it worked great with the 4/5 and a 17 gallon drum.