[alt-photo] Re: ziatype

[Don Bryant]

Looking at the face of my NuArc 26K, the vacuum gauge maxes out at 30 inches
- of mercury. Same for my gauges on my vacuum pumps for my vacuum frames,
ditto for my refrigeration gauges.

If you want to start your vacuum rush you may wish to start reading here:

http://en.wikipedia.org/wiki/Atmospheric_pressure

Then after dinner you can follow up here:

http://nd.edu/~nsl/Lectures/urls/LEYBOLD_FUNDAMENTALS.pdf 

Anyway as a practical matter for printing hydroscopic processes such a Zia
or Pop Palladium, about 5 inches of vacuum will suffice to prevent moisture
draw down. What really helps is to encapsulate the coated substrate in a
sandwich of mylar. 2 mil optical mylar between the film emulsion and the
coated paper surface and a heavier barrier underneath, above anything else
placed on top of the vacuum bed to prevent imprinting of the vacuum bladder
texture.

All of this I think, has been oft repeated over the years here on the list
and other places on the net.

Don


-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org
[mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf Of
EJ Photo
Sent: Thursday, May 03, 2012 8:19 AM
To: 'The alternative photographic processes mailing list'
Subject: [alt-photo] Re: ziatype

I thought the gauges were in psi and not being in front of mine right now I
can't say otherwise. 

Eric Neilsen
Eric Neilsen Photography
4101 Commerce Street, Suite 9
Dallas, TX 75226
 
www.ericneilsenphotography.com
skype me with ejprinter
Let's Talk Photography
 

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