View Full Version : PMK solution B crystals!

kev curry
10-Nov-2009, 01:09
My B solution has gone from very cloudy to totaly clear with the help of the forum and some heat from the radiator, now just 3 days latter, crystals have appeared at the bottom of the bottles!
Funnily enough I was just warned about this in another thread by Eric Woodbury!
I'm I best to bin it and make up some fresh solution!

Eric Woodbury
10-Nov-2009, 11:25
Weird stuff, huh? Man makes plans and god laughs. It is so easy to make fresh, it just doesn't matter.

I asked somewhere if anybody knew if TEA (triethanolamine) could be used instead of Kodalk (sodium metaborate). No firm answer. The pH may not be adequate, but I don't know. I'm not a chemist, that is for sure.

Dave Aharonian
10-Nov-2009, 15:21
A few years back I purchased some PMK from B&S and the solution B arrived with crystals in the bottom. I called Kevin and was told that its a super-saturated solution so its not at all unusual to have some crystals in it. He said I could heat it up a bit to dissolve them but they might just come back. I didn't do anything and used the developer as is, with no problems whatsoever.

kev curry
11-Nov-2009, 11:35
Yes ''weird stuff'' indeed. Ive been periodically heating the solution and shaking the bottle's like a crazy man. Those crystals are determined to stay crystals but there dissolving...slowly! Theres more sodium metaborate in the post.

11-Nov-2009, 12:53
I bought a premixed 2 part liquid Photographer's Formulary solution from BH, and it had the brown crystals. I tried to inquire about this, but received no response. Regardless, I developed some test images, and they came out looking really good. This is my first time using PMK, so I don't know if this is what it's supposed to look like, but it worked well regardless.

CP Goerz
11-Nov-2009, 13:10
The crystals will return if the solution is chilled below a certain point so its best to keep it 'warm' or room temperature. I've never found a few crystals to be a big deal and perhaps its a case of a tiny percentage of loss in 'speed' of development, it can be made up by allowing a longer developing time.

Eric Woodbury
11-Nov-2009, 13:22
One thing I should add, because I had these problems from the beginning, I have for the last 18+ years, used twice as much water to make my part B and thus, twice the B in the final mix. Still, I got crystals. It has only been about 2 years that I have mixed my B fresh each time. My new darkroom is perhaps a little cooler on average than the previous.

kev curry
11-Nov-2009, 14:41
I just went ahead and developed some film with the 'crystallized' solution and the negs look as I think they should... just couldn't wait until the arrival of new sodium met!
I'll try keeping the solution in a warmer place from now on and see how that goes.
Thanks for the help:)

11-Nov-2009, 15:40
Received wisdom has it that Solution B needs to be made up with distilled water or all sorts of crystal problems are likely. OTOH, a small variation in the amount of S. Metaborate will have little to no effect on the action of the developer.

Bjorn Nilsson
12-Nov-2009, 11:21
Even though the metaborate is cheap, there is no need at all to dump it because of clouding or crystallization. All of the neccessary explanations are given above and the metaborate solution doesn't deterioate over time, nothing noteworthy within some 5 years or so anyway.
I.e. warm it up so that the clouding/crystallization is gone or mostly gone. Even 75F should be good enough. As other have posted, you can just go ahead and use the solution as is too. There is no difference. (But don't try to "make up" by adding some extra sol B, as this will change the potense of the developer quite drastically. E.g. double sol B will cut dev.times by e.g 30% or so, with a somewhat different end result.)