Re: [compost_tea] Re: Mesh & Microns - and poly questions

From: Jeff Young <sharkman_04101_at_yahoo.com>
Date: Tue, 23 Sep 2003 16:20:52 -0700 (PDT)

Group,
 
Reading this thread has put a smile on my face. I run across this mesh/micron problem frequently in the vitamin end of my business. Therefore, I have a conversion chart posted on the wall in my office. Below are some of the conversions:
 
Approx. Microns U.S. Seive Market Grade
 
403 40 mesh
389 40 Mesh
297 50 mesh
282 50 Mesh
250 60 mesh
231 60 Mesh
177 80 mesh 80 Mesh
149 100 mesh 100 Mesh
105 140 mesh 150 Mesh
74 200 mesh 200 Mesh
37 400 mesh 400 Mesh
 
You can see how the two different styles of screen have different sized holes at most mesh sizes, especially with the larger openings.
 
I don't have conversions for sizes smaller than 40 mesh. 40 mesh is .4 of a millimeter. Larger than that you can almost start to measure.
 
Here we use stainless steel screens. They work great and are durable. I know that you can buy this material in any mesh size you like, in sheets. If anyone is interested, I can post the places that sell it.
 
Kindly,
Jeff Young
President
Advanced Marine Technologies
49 Hassey Street
New Bedford, MA 02740
Tel: (508) 991-5225
Fax: (508) 991-3033
www.organicgem.org
 
 


a1l2e3x4ar <xela_at_netgate.com.uy> wrote:
Kirk:

don't mess with the math of the mesh

the conversion, IMHO, shd be as follows 25,4mm(1") /20mesh = 1.27mm,
or 1270mc, so that 30mesh can't be 600mc: 25,4/30 = 0.847mm or 847mc.

correct me if I'm wrong, but according to this, those folks worried
by 3,5mc-fungi not passing thru a 20 mesh (or 30 or 50 for that
matter) may be at ease

cheers
alex
--- In compost_tea_at_yahoogroups.com, "Kirk Leonard" <kirk_at_o...> wrote:
> > So Kirk what size screen do you use to filter ACT? Last Friday I
> > ordered a #12 mesh for $67. I decided to get the coarsest, which
I
> > thot might not plug the nozzles. I may wish for a #20 soon.
Dennis
>
> So what size holes does this mean? Per Mike's sample table, #12
seems like
> maybe 1400 microns*(1.4mm)? Plastic or wire? Must be chunky
material.
> Where/who from? Just fabric or a formed/mounted filter? Seems
sorta
> "spendy"
> as we say hereabouts...
>
> I don't filter ACT but have friends who use same paint filters
(which are a
> buck or two) I described to do that. I've been using two different
sizes of
> paint filters to contain compost during tea making, one with about
1mm X
> 1/2mm holes, another with holes approx 3/4mm X 1/2mm. Picked up
some
> polyester fabric recently with holes that look to be about 3/4mm
square to
> make my own filters. None of these have mesh ratings I could find
from
> makers.
>
> Blowing all this out of the water, I wonder about polyester filters
(all
> paint filters I've seen are polyester), suspecting they could
inherently
> cause fungal hangups. Seems to me the "poly" fibers could fuzz up
and
> tangle hyphae, even bacteria, especially after some use and wear.
Judging
> by discoloration, I think that happens. So I was pleased to
finally find a
> monofilament nylon filter the other day - the 600 micron/"about 30
mesh" I
> mentioned - thinking it'd be less likely to do that. It's also
much more
> substantial material, so should last longer in addition to being
more
> cleanable. Might go for an "about 20 mesh" fabric - at my new
source that's
> 800 micron openings - myself. Expect it'll cost a good bit more
than paint
> filters. Anybody found a good monofilament paint filter out
there? They
> seem to be in a good opening size ballpark, whatever the mesh...
>
> Are you guys messing with me here? Or meshing?
>
> -- Kirk
>
> *Another micron measure for those who haven't heard it: An average
human
> hair is said to be 100 microns in diameter. Maybe that's the way
we should
> describe this stuff... is it 6 hairs or 12 hairs wide, hmm?
All "split
> hair" suggestions also accepted... just trying to get this
mesh/micron stuff
> straight.


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Received on Tue Sep 23 2003 - 20:01:36 EDT

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