RE: [APML] D-19 Development Question

["Richard Klappal" <klappal@xnet.com>]

D-19 has good keeping (storage) properties and it is uncertain how evenly
mixed the various component powders are in the dry mix, so separating the
powder, and mixing as needed was discouraged, historically.

Better, I think, would be to mix the entire gallon, then separate into your
+/- 12 oz portions.  Store in GLASS bottles or PLASTIC bottles that do not
permit oxygen to migrate. Bottles should be FULL, using glass marbles to
take up excess space or squeezing the sides of the plastic bottle to remove
all air before sealing the bottle. (You could also leave the gallon intact,
using the marble technique to keep the bottle full.)

As with other comments elsewhere, I am (was, when my darkrooms was
functional) a firm believer of HC-110 Dilution B (1 oz HC-110 + 31 oz
water).  Dilution A (1 oz HC-110 + 15 oz water) is the high activity mix.
These were for traditional exposures; Jerry or others can comment on the
effectiveness for astrophotos.

Rich


-----Original Message-----
From: astro-photo-bounces@seds.org
[mailto:astro-photo-bounces@seds.org]On Behalf Of Allan & Julie Whetzel
Sent: Tuesday, 07 October 2003 01:11
To: Discussion of Film Astrophotography
Subject: [APML] D-19 Development Question


Hello,

I'll be trying some galaxy shots on 35mm Tech Pan in the coming weeks
and they will be developed with D-19. I just purchased the D-19 mix and
have read in the APML archives that the powder can be broken into
portions and then stored in the freezer  - mixing for development as
needed.

My development tank uses 11oz for a single roll -  so my math shows
that I should be able to get 11 tanks of 11.64 oz out of the mix (the
package says the whole thing makes 1 gallon and there are 128 fluid
oz's in a gallon). I just want to verify with the guys that do this all
the time that I'm thinking correctly. Just break the mix into 11 equal
portions and add 125 degree water to each to create 11.64 ounces and
I'm good to go for development at the correct concentration - right?

Thanks for the assist,

Allan Whetzel

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