Thank you, Richard. Marking this to read later today!
" Rodinal was the first packaged developer, going on the market in 1891."
WOW. Interesting. and guess what? One of the guys here is sending me a
bottle. Wahoo. I'm looking forward to playing with it.
Janet
On Fri, Apr 17, 2015 at 10:18 PM, `Richard Knoppow <dickburk@xxxxxxxxxxxxx>
wrote:
On 4/17/2015 5:49 PM, Janet Gable Cull wrote:
Thank you, all!variations at:
I found a discussion of the Rodinal formula along with some
https://www.flickr.com/groups/rodinal/discuss/72157633978523578/
This may be of interest to those who would like to mix something up
to try. The formula given uses lithium hydroxide, which I have seen
mentioned in old books as being used by Agfa early on. But there is also
information for a formula using potassium hydroxide which is much cheaper
and is probably what Agfa used during most of the production life of the
product. Potassium hydroxide is superior to sodium hydroxide for this
application because it will dissolve to a higher concentration. The
paraminophenol is dissolved to a slightly oversaturated state. When the
solution is cooled some of the paraminophenol will come out of solution and
form crystals at the bottom of the container. This is necessary for long
life although the late commercial product did not have the crystals in it.
Since there is very little sulfite the solution tends to turn brown rather
quickly. However, this evidently does not interfere with its performance.
Please note that Rodinal Special is not a variation on Rodinal, it
uses a completely different developing agent.
Rodinal was the first packaged developer, going on the market in 1891.
--
Richard Knoppow
dickburk@xxxxxxxxxxxxx
WB6KBL
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