The Mask Thread

Off-topic Chatter
1

Post mask sources and info here.
Since there is so much interest in masks these days…
I though it might be helpful to create a thread just about masks.

I’ll start off with a site that has info about the effectiveness of various masks.
The effectiveness of DYI material.
It’s disconcerting to see that some masks only stop about 50% of the particles.

Can Masks Capture Coronavirus Particles?

What are the best materials?

And their list of articles

DYI Masks:

The Aggie Mask
No sewing. Easy to make. Fast. Seals well on most faces. It was a bit small on me and may need to be scaled up if you are a larger person.
https://enmed.tamu.edu/DIYmasks/

CraftPassion Mask
One of many in this type of design for a cloth mask with a filter pocket. Typical of many – many of the designs out there.
Requires sewing and some skills. Needs to be fitted well to make a good seal. This is critical.

Unity Health Care Mask
The same type of mask from “makers” at a health care place.
Sewing required.
The key thing to note is that they say to correctly seal the mask – skin safe double sided tape is required.

The Duck Mask
A doc shows his design using a HEPA vacuum bag.
Sewing (or stapling would work). Single material. Seals to the face well. Needs to be enlarger for Texas sized people (like me).

Other Stuff

Copper Wire
From a few experiments I’ve found that 14g or 16g solid copper wire makes a good nose clamp thingy for masks. It is way stiffer than pipe cleaners or??
It’s a pain to get it adjusted but it won’t get pulled out of shape if the mask is pulled tight.

Gorilla Tape.
This stuff sticks to rubber bands and cloth really well. I have used it to put on the nose clamp thingy instead of sewing through the mask (and risking the integrity of the filter material).
I tried sewing through it and it gums up the needle PDQ – so that was a fail.

All the best,
Jeff

2

Are you aware that Smart Air Filters is in the business of selling masks and other industrial protective equipment? And that the data they’re citing is very selective to allegedly support their product being used as protection from the current health threat? And that the one study they cite to support their claim that masks protect people from the coronavirus was a study of whether a respirator could filter enough air pollution particulate matter to lower the subjects’ blood pressure - not a study to determine if airborne viruses are blocked well enough to prevent infection?

3

NorthernHarrier

Indeed they are promoting their stuff. But are the test results they reference about other makers masks and DYI material being able to filter a certain particle size not valid?
Only very recently have anything been coming out about that actual effectiveness on the bug.
Clearly any source should be take with a large grain of salt.
And I certainly don’t intend to promote any specific products.

But I have made examples of the craft place mask, the Aggie mask, and the Duck mask. And I just reported on what seems to fit and seal to my (rather large) face. (Did I just admit that I have a fat head?)

The Aggie mask recommends minimum filter material as well as the number of layers to be effective.

Hopefully BLFs will also post supplies (when available) here also.
All the Best,
Jeff

4

…I really thought this was going to be about the Jim Carrey movie.

5

And a new product line and spokesman are born!
All the Best,
Jeff

6

a mask is mostly useless without eyes protection too… if you are infected then a mask is good if you want to prevent spreading

7

The CDC shows how to make a mask in 45 seconds.

All the Best,
Jeff

8

Jeff, I’d just like to say thanks for posting this. :+1:
Yeah, it may not be perfect advice, but you did it, that’s the main thing.
I currently am constructing (or my mum is lol) a type of hybrid between the hepa bag mask, and the nice looking fabric mask with pocket, for all the family - shes 72 and bored stiff and can still sew on her machine ok - it will give her something to do!
I explained she is definitely going to have to wear a mask when she eventually can go out and they are not available - and to be fair - some of these home made ones (done right/using right materials) are way better than those cheapie disposables anyway!

9

From shores of Albion, where the steam engine, the jet turbine, the torpedo and the tin can were invented, comes THIS solution. For when you are desperate need of some form of protection. Makes social distancing easy.

10

Just make sure to buy new ones of those, not used.

Unless you’re into that sort of thing. :sunglasses:

11

in the US, reusable shopping bags are ubiquitous! these are predominantly made from a fabric called non-woven polypropylene which is widely used for inner and outer layers of N95 masks. the filter medium is usually made from meltblown polypropylene but that is almost impossible to get nowadays. for “civilian” use, most likely two layers of the non-woven would be adequate. if interested, you can go to https://makermask.org/ for more info, patterns, and instructions. if really interested there are links to the science on the site as well.https://makermask.org/

12

Oops.
Made a double post some how.
Deleted this one.

13

COVID PANDEMIC 3D PRINTED MASK TUTORIAL

14

Making Masks, some thoughts.
These are just some observations. Please do not think I have any real expertise in the construction or effectiveness of, well, anything.

The problem I’m finding with many mask designs is the lack of surface area in the “filter area”.
The one’s that simply press a bunch of layers of cloth against your face essentially limit the intake filter to the area just around the mouth and nose.

I also find this true of many designs that have the vertical seam in the front. If that seam is too close to the face, most of the mask is flat against the cheeks and is not passing air on inhalation.

This small filter area, coupled with many layers of cloth, restricts air flow – breath-ability as it were.
It only takes a little restriction to make most people feel stifled in a short while.

One solution is to look for a material that passes air more easily. Say cotton tee-shirt vs dish towels.
But, at least to me, it seems kind of a trade off. Better air flow vs filtration.

A partial solution is to make more room in the front of the mask. On constructed masks, make sure there is extra room out the front so the cloth sits well away from the face.
Thus increasing the active filter area. Maybe incorporate a twisty-tie in the front seam to keep it stiff if needed.

With the “Stuff a bunch of layers over your face” design…
Some fussing with coat hanger wire, pipe-cleaners, (?), and duct tape could create a pocket in the front to increase the filter area.

Nose Clamps
I’ve also found that the pipe-cleaner as nose clamp thingy is kind of wimpy.
To get a fit that stays put, 3 or 4 pipe-cleaners twisted together is a minimum if I want to put any tension on that area (and I do). I use solid copper wire – 14g. Way stiff and you just can’t crush it against your face for a fit (if you want to keep your personal nose intact).

I also like to put the nose thingy on the outside of the mask using a really strong tape instead of sewing through the mask. Not a big deal with the multilayered cloth designs (the stitch holes seem to be self sealing). Poking holes through a HEPA layer seems like a bad idea to me. The HEPA layer is thin and doesn’t seen to rebound when cut.
If you can put the nose thing on by only compromising the outer cloth layer, that seems OK.

Face Bondage
The designs that hook over the ears, unless the tension is very light, become uncomfortable if worn for many hours.
Most designs can accept ties that go over the head and neck instead of around the ears.
Many shoe laces have some elastic qualities and help with the fit.
Pulling the guts out of para-cord and using the sheath gets rid of the cords tendency to roll off the crown of the head.

Cord Toggles
Tying off the head straps takes some practice and is hard to get right.
Check out your pajamas, sweat shirts/pants, and outdoor gear.
Look for those toggle thingies that are used to adjust the cords. Most most will come off by untying a knot at the end.
These make great adjustments for masks ties. No fumbling with knots.
And they can be adjusted on the fly to adjust tension.

The same gear often can be a source of elastic cordage for the mask ties.

And yes, some sort of eye covering is highly recommended.

Don’t Tip Your Hat
My doctor also says to wear a hat.
Hair with it’s natural oils is a great trap for cooties.
The brim on a hat also greatly reduces the particles that get behind eyeglasses.
This has been known trick in kitchens for years.

Non-Woven Cloth
The grocery bags are gone.
But many Shop Towels are some sort of non-woven fabric.
Check out local auto parts stores for supplies.

Keep Safe,
All the Best,
Jeff

15

What’s Inside 3M N95 Respirator Masks? Find out!

Best mask material: 4.55

16

https://www.medline.com/jump/category-content/media-room/press-releases/2012/03/Medline-Introduces-Nations-First-US-Antiviral-Face-Mask-that-Inactivates-Flu-Viruses

17

https://www.aliexpress.com/af/-Polypropylene-cloth.html?trafficChannel=af&d=y&CatId=0&SearchText=+Polypropylene+cloth&ltype=affiliate&isFavorite=n&SortType=total_tranpro_desc&page=1&groupsort=1

18

We used ‘Henry’ hoover HEPA bags, cut into mask shapes to fit inside the ‘craft passion’ pocket type mask. We used paracord and a toggle for closure and 2 soldered together thick ish copper wires for the nose pieces.
They work and fit extremely well, I’d say they are on par with any other mask and the 3 layer hepa bags are almost identical to the stuff used in an N95 mask.
These craft passion masks fit so well once you have learned and made a few - my mother has made around 20 now for family and friends, each supplied with 3 filters which I cut from the bags.
You can double this up to 6 layers if you like, but it’s harder to breathe.
Her next version will incorporate the ‘valves’ which you can also buy - I will seal them in with silicone.

19

Thank you. :smiley:

:beer:

BTW, I’ve been using a clean bandana mask every time I shop.
Local N95 seem to be in short supply or over-the-top expensive online. YMMV

20

A few more observations about making masks.
After doing some very nonscientific testing…

As the mask is used, outside air takes the path of least resistance. (I am Captain Obvious).

I now think any stitching through the mask in areas that are “pressurized” as it were from breathing must be sealed to prevent air from passing through the needle holes. Thus letting unfiltered air into the “safe” side of the mask.
This includes internal filters that may be stitched – and – areas that hold the filters.

Any seams in the pressurized areas must be sealed where exposed to external air to prevent air from slipping between layers and entering the needle holes or passing between layers into the ’safe” side of the mask.

I have been using hot glue to do this by running a thin smear on the outside of stitched seams and along the seams where parts of the mask are sewed together.

I think Super Glue, Elmer’s, latex, or any of the many hobby glues would work.
Test them on a scrap to be sure the stuff won’t eat the material.

Note – I am using a cheapo glue gun that has both high and low settings.
The High setting is hot enough to melt the polypropylene in the HEPA bags I’m using to make mask filters from. Test before use.

Somewhere, someone posted a link to a video of a UK (?) doc saying not to use HEPA or other filters from – well – other filters. He stated that they were made of fiberglass and using them would put deadly glass fibers into your lunge.
Too true if the filters are fiberglass.
But if vacuum filter can put out fiberglass, is it not doing so every time I run the vacuum cleaner?

Dissecting two HEPA vacuum bag types I found them to contain the same looking stuff as an N95.
Non-woven poly cloth. The seams in the bag are fused with heat and it melts at a very low temperature.
The link from bwl123 a few post up shows the same stuff I found in my filter material.

My take is to test any filter to check if it looks to be made from fiberglass.

Only the very cheap furnace filters I’ve looked at seem to be made from fiberglass.
The MERV level of these cheap filters is too coarse to use for a filter mask.

I posted a link to an article in The Atlantic about why everyone should mask up in the big Corona thread. I’ll do it again here since stuff gets covered up fast over there.

Masks for Everyone
From The Atlantic:

Link to the layperson version of the study.
https://www.fast.ai/2020/04/13/masks-summary/

To better understand what level of mask-wearing we need in the population to get this pandemic under control, we assembled a transdisciplinary team of 19 experts and looked at a range of mathematical models and other research to learn what would happen if most people wore a mask in public. We wrote and submitted an academic paper as well as a layperson’s summary. Every infectious disease has a reproduction rate, called R. When it’s 1.0, that means the average infected person infects one other person. The 1918 pandemic flu had an R of 1.8—so one infected person infected, on average, almost two others. COVID-19’s rate, in the absence of measures such as social distancing and masks, is at least 2.4. A disease dies out if its R falls under 1.0. The lower the number, the faster it dies out.

Models show that if 80 percent of people wear masks that are 60 percent effective, easily achievable with cloth, we can get to an effective R0 of less than one. That’s enough to halt the spread of the disease. Many countries already have more than 80 percent of their population wearing masks in public, including Hong Kong, where most stores deny entry to unmasked customers, and the more than 30 countries that legally require masks in public spaces, such as Israel, Singapore, and the Czech Republic. Mask use in combination with physical distancing is even more powerful.

Keep Safe – All the Best,
Jeff