Re: Face mask design drag race - reply from Tim Spurgeon

Tim Spurgeon

Fred (AE0FD):

Thanks for the information and good source for construction of face masks. My wife Susan has sewed face masks for the both of us,
that has a pocket where additional filter medium can be inserted. For example, over the weekend I discovered a vacuum filter with a
pore size of 0.1 microns. This is one third the pore size of a N95 face mask filter. So we are planning on cutting pieces of this material
and placing it in the pocket of the face masks.

About the same time I found a zip bag with N95 face masks, that I purchased in 2016. Good news and bad news. It turns out that 3M
N95 face masks have an expiration date. Namely, the foam rubber strip around the nose degrades and crumbles. I found another N95
that I had worn while mowing my lawn; the foam rubber strip was crumbling.

So, I think that while we are in the midst of the pandemic, we need to consider making out own.

Fred, do you know if the material mentioned in the Youtube is available?




----- Original Message -----
From: "Fred Dittrich" <>
To: "main" <>
Sent: Monday, April 6, 2020 10:19:55 AM
Subject: [CMRA] Face mask design drag race


Here is a video of an MD performance testing four different face mask
designs. She also introduces a material used to wrap surgical tools
before they are autoclaved. I sewed and fit tested
four different face masks...


Fred AE0FD

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