Re: lith film and pinholes

[John Cremati <johnjohnc@core.com>]

       I had a problem at a Commercial Printing outfit where they constantly
had pinholes in their lith film..... Most was due to dust in the building as
in the printing process they have a powder system to prevent freshly printed
paper from sticking to each other The printing dust is a major problem as it
gets into everything............ We installed special tape on the floor
entrance so when people came thru the door the dust from their shoes would
stick to the adhesive.. The tape was changed every few days as this tape
comes in 12 layers and you just peel off a new layer........ We then
installed a air filtration system in the room that recirculated the air thru
the filter continuously.... The  ventilation intake to the exhaust air was
also filtered...They were still having problems after all of that so I
installed a separate heating and cooling system in the room... If you have a
small darkroom,  a window AC unit would work and some electric baseboard
heat, you can also get window AC units with electric heaters in them
........ A water filtration system was installed, and electrostatic air gun
to blow away the dust on negatives and lenses ...... The room is cleaned
frequently using " End Dust" on cleaning utensils....... What dust was
entering the room was probably  coming in on the workers clothes... I
suppose  lab coats would be a good idea.

John Cremati.


----- Original Message -----
From: "Diana H. Bloomfield" <dlhbloom@mindspring.com>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Monday, May 06, 2002 11:40 AM
Subject: Re: lith film and pinholes


> Hi Christina,
>
> I used to get pinholes all the time--didn't matter what film I used.  So I
> started using plain water between development and fix and had no more
> problems.  Recently, I used some larger film and went back to using a very
> dilute stop bath, because I was worried, I guess, and the pinholes
> reappeared. That did it for me.  I'm just using water now.
>
> --Diana
>
> "Christina Z. Anderson" wrote:
>
> > Is there any way to minimize pinholes in lith film?  Do you all not use
an
> > acetic stop in between developing and fixing?  Or should I just suck it
up
> > and get out the opaque?  I developed it in Dektol 1:6, APH.  Weak acetic
> > stop bath.
> > chris
>
>