cramer@uunet.UU.NET (Clayton Cramer) (02/01/91)
I've been meaning for some time to buy gas masks, principally for
railroad accidents. (It seems that railroad cars of ammonia,
chlorine, and other charming substances get derailed far too
often in the U.S. for me to be completely comfortable without
some limited ability to protect my family from accidental
gas warfare). The Gulf Crisis sort of pushed me over the edge
to get around to buying masks.
I obtained surplus (but apparently never used) German gas masks
that are roughly equivalent to the Israeli surplus gas masks
that were so available for the last two years or so. I have a
question concerning the filters. I know that leaving the filters
open and installed on the mask will destroy the filter. Is it
exposure to the air that does it, or is it flow through the
filter? Would it shorten the lifetime of the filter significantly
to install the filter, but leave the outer seal on the filter
in place? (Therefore, only one seal is open -- the one that
points into the mask).
--
Clayton E. Cramer {pyramid,pixar,tekbspa}!optilink!cramer
"The tree of liberty must be watered periodically with the blood of tyrants
and patriots alike. It is its natural manure." -- Thomas Jefferson
You must be kidding! No company would hold opinions like mine!rja@Eng.Sun.COM (Robert Allen) (02/06/91)
From: rja@Eng.Sun.COM (Robert Allen)
In article <1991Feb5.041457.4841@cbnews.att.com> wmartin@STL-06SIMA.ARMY.MIL (Will Martin) writes:
+
+
+From: Will Martin <wmartin@STL-06SIMA.ARMY.MIL>
+Recent TV news coverage has discussed the US M-17 gas mask, which is being
+used in the field right now, but which is going to be replaced eventually
+by the improved M-40 model. Much was made of the M-17's obsolete filter
+design, which requires the mask be removed to replace the filter
+elements buried in the cheeks of the mask. However, the actual
+replacement process was never illustrated.
+
+I happen to have an M-17 mask (found it at a garage sale!), and I can
+feel the filters inside the mask but cannot for the life of me figure
+out how they come out for replacement. Can someone post or e-mail me
+the instructions for filter removal and replacement on the M-17?
Since it might be of general interest, I'm posting it instead of mailing
it. There are actually parts which must be replaced periodically, though
I think the filters are replaced more often than anything else. If you
snap off the fuzzy intake covers on the cheeks of the mask, you'll see
the filters inside the mask. The colour of the metal ring projecting
through the mask determines what kind of filter it is: green is (I think)
full NBC capable, and other colours are for use only with riot control
agents. If you look at the inside of the snap off covers, you'll see
round membranous rubber valves. After some period of time (6 months?)
these need to be replaced. They are replaced when they are no longer
soft and pliable. There are similar filters in the nosepiece inside
the mask (2). The exhaust valve is heavier rubber and is in the front
piece of the mask, under the metal voice box. You have to remove the
rubber exterior "nose" to see this valve. To remove the filters, you
look inside the mask, and you'll see some "snaps", which are actually
metal tabs projecting through the rubber. You undo these, and from
there you should (as I recall) be able to see the mesh covered filters.
I've never taken them out, but in the mask i looked at, it looked as if
you'll have some pretty serious tugging and stretching to get the thing
out.
There are maintenance manuals available for the masks from various
military surplus places.
DISCLAIMER: the information supplied above is for casual informatino
only, and is not intended as advice to be used in a potentially life
threatening situation.
+
+I see lots of the Israeli masks and spare filters in surivalist magazine
+ads and surplus catalogs, but don't recall having seen the filters for
+the M-17 advertised. Are they for sale in the retail market anywhere?
They were available in the past, but seldom advertised. I believe
Sherwood Ind. (?) in Parthenia CA used to carry M-17 parts.
--
Robert Allen, rja@sun.com DISCLAIMER: I disclaim everything.
"The intelligent man is one who has successfully fulfilled many
accomplishments, and is yet willing to learn more." - Ed Parkeramoss@cs.huji.ac.il (Amos Shapira) (02/09/91)
From: Amos Shapira <amoss@cs.huji.ac.il> In sci.military optilink!cramer@uunet.UU.NET (Clayton Cramer) writes: >open and installed on the mask will destroy the filter. Is it >exposure to the air that does it, or is it flow through the >filter? Would it shorten the lifetime of the filter significantly >to install the filter, but leave the outer seal on the filter >in place? (Therefore, only one seal is open -- the one that >points into the mask). The orders we got with the masks were that once the filter is open there is no use in sealing it, on the conterary: you might forget to remove the seal before using the mask and suffocate to death (it happened here in Israel). The filters are supposed to be usefull for 6 months after openning and 6 hours of actually contacting gas. As long as you don't open them they should be good for several years (don't remember the number) but even then you should do some annual maintanence. You better adopt a simple strategy: DON'T open them until you really fill that you are going to use them. After openning them, DON'T close them but just put them inside a sealed plastic bag. In any case, NEVER let the filter be in contact with water or high humidity. Hope this helps, Amos Shapira Hebrew University, Jerusalem Israel amoss@shuldig.huji.ac.il