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Old November 30th 13, 08:30 PM posted to
Jean-David Beyer
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Posts: 247
Default Zone VI Archival Print Washer Parts

On 11/19/2013 11:48 PM, wrote:
Does anyone know how to control the overflow? When the water reaches the top it pours over onto the floor. I hope someone wil reply.

I have a Zone VI print washer, 11"x14" size (i.e., it will wash prints
that size or a little larger, but not 16"x20".

The way I run it, tempered water flows in the hose connection at my
upper right into a plenum chamber. While in there, some of the dissolved
air comes out of solution. I wish it all did.

From the plenum, the water enters the main chamber through to rows of
small holes; one row near the top (but below the water level) and
another row near the bottom. After the water has washed the prints, it
exits the washing chamber through holes at the bottom into the exit
plenum. Picker did that because he believed hypo is heavier than water
and it would sink to the bottom. That happens to be nonsense, but it
does not really matter. The water rises up in the exit plenum and goes
out the overflow pipe.

_There is no reason whatever for the washer to overflow_. The exit pipe
is about one inch in diameter and the intake pipe is effectively about
3/8 inch. There is little point running much over 1/2 gallon per minute
through that, since washing is a diffusion limited process. But even if
you run a gallon a minute, it should never overflow.

What flow rate could you be running that the water comes into the tank
faster than can escape from the large drain pipe? I have never had it
come anywhere near the top.

The biggest problem I have with the washer is that not all the air comes
out of the water in wintertime in the entry plenum chamber, so some of
it comes out on the prints. I wrote to Fred Picker about that and he
said it was not a problem because the bubbles grow in size and float off
the prints and they do not impede washing. Well, I have studied them and
they can remain firmly in place for over 15 minutes, and they do impede
washing. So every 5 or 10 minutes I quickly raise each print and briskly
reinsert it to get the bubbles off. They are caused by mixing the cold
winter water with the hot water to get wash water the right temperature.
I tend to do my B&W processing at 75F because I cannot reliably get it
colder than that in the summertime, and I prefer to use the same
temperatures all year long.

.~. Jean-David Beyer Registered Linux User 85642.
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