jaelien
off to a rocking start
Member since September 2020
Posts: 2
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Post by jaelien on Sept 19, 2020 15:55:28 GMT -5
Hello! First time here, hopefully this is a good board to post this in:
I sand rocks by hand as a hobby. Recently, I purchased some 6k, 12k & 60k grit sandpaper (wet & dry so I can wet sand to reduce dust), and i'm keenly aware that my current N95 mask is barely adequate for the 3k grit I was going up to. I've checked online and 60k grit is roughly 0.5 microns, so that's the number to aim for in my filter. With Covid-19 going on, it's difficult to find information on this specific topic without being bombarded with cloth or paper face masks; what I need is a full or half respirator-style mask that has a proper filter in it.
Does anyone here have a recommendation for what masks you might recommend? As stated above, it has to have a filter (or adaptable to one) for at least 0.5 microns, and ideally somewhere under $100 USD (though if not, it's still worthwhile to save my respiratory tract).
Thanks, and I hope you've all been staying safe doing what you love!
(P.S. I know sanding by hand is seen as tedious, stupid, confusing, etc; please try to keep on topic of the thread. I do not want to use a tumbler, full stop.)
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Post by aDave on Sept 19, 2020 16:22:15 GMT -5
Hello! First time here, hopefully this is a good board to post this in: I sand rocks by hand as a hobby. Recently, I purchased some 6k, 12k & 60k grit sandpaper (wet & dry so I can wet sand to reduce dust), and i'm keenly aware that my current N95 mask is barely adequate for the 3k grit I was going up to. I've checked online and 60k grit is roughly 0.5 microns, so that's the number to aim for in my filter. With Covid-19 going on, it's difficult to find information on this specific topic without being bombarded with cloth or paper face masks; what I need is a full or half respirator-style mask that has a proper filter in it. Does anyone here have a recommendation for what masks you might recommend? As stated above, it has to have a filter (or adaptable to one) for at least 0.5 microns, and ideally somewhere under $100 USD (though if not, it's still worthwhile to save my respiratory tract). Thanks, and I hope you've all been staying safe doing what you love! (P.S. I know sanding by hand is seen as tedious, stupid, confusing, etc; please try to keep on topic of the thread. I do not want to use a tumbler, full stop.) Welcome to the forum. Take a look at this website and see what guidance you can get through it. It *appears* that the number that is associated with masks (95, 100) is based on the ability of a rated mask to filter a percentage of matter that is .3 microns or larger. Since, you're grit is larger than .3, then you may be okay with 95 or 100...it just depends on what your comfort level or need is. I just don't know what size the dust particulates are. I'm not a mask user (don't have the need), so I can't get you a particular model. You might be able to get by with a half-mask with N100 cartridge filters at a place like Home Depot. Heck in addition to mask rating info, it looks like the site I found is also a vendor. Maybe they can answer your questions in more detail. Good luck. www.envirosafetyproducts.com/resources/dust-masks-whats-the-difference.html |
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Post by Pat on Sept 19, 2020 17:05:22 GMT -5
There has been a discussion of masks on this forum. Can you do a search? I remember Biker Randy made some knowledgeable comments. I’ll try to look later. It’s an important subject.
Welcome from California.
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Post by aDave on Sept 19, 2020 17:22:18 GMT -5
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Post by manofglass on Sept 19, 2020 19:38:21 GMT -5
Welcome to the forum
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Post by hummingbirdstones on Sept 20, 2020 9:29:15 GMT -5
Try looking at some industrial supply companies like Grainger or MSC Direct to see if you can find what you need. One other option would be to check into the ones they use in the automobile painting industry. I'd think those would need to be pretty heavy duty.
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Post by pauls on Sept 20, 2020 16:54:19 GMT -5
Yes I agree with Hummingbirdstones, the auto painting ones have carbon canisters but are incredibly comfortable, being made to be worn for long periods they are easy to breath through and are very snug on the face. They are possibly a bit over the top for what you are doing but they are good.
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Post by stephan on Sept 22, 2020 14:25:41 GMT -5
3000 grit is 6.5 microns. 50,000 grit is 0.46 microns.
A quick rule to remember is that grit size is particles per square inch, not linear inch, and there are 25,400 microns in an inch (thus >645 million square microns per square inch). Long story short, a micron is pretty darn small (one millionth of a meter).
As for masks, remember if you keep the stone wet, there won't be much dust. If you do it outside (or have open windows), the ventilation will be your friend. So, in many cases, a nuisance dust mask will be perfectly adequate. For an N95, N99 or cartridge mask to work, it needs to be properly fitted (usually determined annually with a smoke, taste or irritant test), you need to be clean-shaven (even a 5 o'clock shadow will interfere), and not have any hair caught in the sealing zone. Masks are also hot, steamy and restrict your breathing, so most people end up wearing them in a way that renders them ineffective (using only one strap, straps loose, etc). Bottom line, I wouldn't waste my money. I would grind wet and maybe use a nuisance dust mask (these have one strap, not two).
If you do decide to go with a cartridge mask, 3M makes very good one. You would only meed a particulate filet (not OV, AG or amine). Coding on the particular filters is as follows:
95, 99, 100 refers to percentage filtered ("100" is actually 99.8%, but close enough in this case)
N refers to Not oil resistant
R stands for oil resistant
P stands for oil proof
(this could be an item to note for those who are concerned aboutslabbing large amounts of stones that could have chemical hazards)
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Post by stephan on Sept 22, 2020 14:28:07 GMT -5
One more note: Those with respiratory impairments (such as emphysema) should be very careful about wearing tight fitting masks for long periods of time. In the workplace, OSHA actually requires a pulmonary fitness test before you can enter a respiratory protection program.
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Post by stephan on Sept 22, 2020 14:31:49 GMT -5
If you are truly concerned, and are a smoker, have breathing issues, or a beard you're not willing to part with, there is always the PAPR (Powered air-purifying respirator) option. The cheapest I've seen: microclimate.com/pages/air-detailAdded bonus, if you wear it in public, people might think you're an astronaut. |
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Post by stephan on Sept 22, 2020 14:32:45 GMT -5
Try looking at some industrial supply companies like Grainger or MSC Direct to see if you can find what you need. One other option would be to check into the ones they use in the automobile painting industry. I'd think those would need to be pretty heavy duty.
Charcoal is more about organic vapors than particles |
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Post by stephan on Sept 22, 2020 14:34:22 GMT -5
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islander
off to a rocking start
Member since May 2020
Posts: 15
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Post by islander on Sept 22, 2020 16:10:49 GMT -5
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Post by stephan on Sept 22, 2020 22:56:48 GMT -5
P3 is the rough equivalent of American P100, and rated for both solid and liquid particles
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jaelien
off to a rocking start
Member since September 2020
Posts: 2
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Post by jaelien on Sept 25, 2020 20:45:17 GMT -5
Many thanks to all and sundry who've replied - I think ultimately i'll give my normal N95 mask a try and see what the results are. I find my throat gets a bit scratchy by the 2 hour mark (roughly how long it takes to polish from 80 grit to 3000 grit), and that was in a backyard with full wet sanding. Hopefully it's not worse with the extremely fine grits, but we'll see! I'll definitely be looking into those recommendations, I appreciate you all taking the time to find/suggest them!
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Post by Peruano on Sept 29, 2020 14:29:11 GMT -5
This has been a great educational thread for an important topic. Its nice to have folks that are authorities on the subject. One point that tends to escape notice in these kinds of discussions is although we work wet, we often (me included) allow the wet dust to dry and aggregate in significant quantities in our work space, still available to breath and cause problems. So . . . clean up that dust often and pay attention to how it might enter your nasal mucosa and pulmonary tract. Many of us wear masks when working with some materials but spend much greater amounts of time in the workshop without masks when those contaminants might still be present and even suspended in the air.
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