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Mixing Pyrocat HD in glycol

Mainecoonmaniac

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I tried for the first time in mixing Pyrocat HD in glycol. I followed the directions from http://www.pyrocat-hd.com/html/mixing.html.


Somehow, there are some still undissolved bits in the final mix of part A. Is there a way to get all the chemistry to dissolve into the glycol?

BTW, I processed some film with the solution and it works fine.
 
Do you remember at which stage the dissolved particles first appeared? The usual instructions are to ensure that each added chemical is totally dissolved before adding the next. Sometimes though the undissolved bits appear after everything has been clear, especially at low storage temperatures. My guess would be it's one of the water soluble components, bromide or metabisulphite. Actually the bromide is hardly necessary (Sandy King) except when absolutely minimal fog is needed for alternative processes. I haven't put bromide in my Pyrocat for years
 
Glycols are good solvents for various organic chemicals . If you are patient the catechol and ascorbic acid should dissolve without heating. There is a danger in the developing agents oxidizing if they are heated. This is particularly true for developers containing TEA. If necessary put the mixture in a hot water bath and agitate periodically. I personally have never experienced any sediment.
 
Thanks for all the great tips. I think I my glycol wasn't hot enough or I mixed the sequence of chemicals wrong. But I really like Pyrocat HD. I used PMK Pyro for years and I've had good results. But sometimes it's unpredictable and inconsistent. Still new to Pyrocat HD and so far, I like the results. I plan to use it for stand development for high contrast negatives.
 
You need a little water to dissolve the Metabisulphite.

I've used Pyrocat HD for 12+ years now, Part A keeps very well just made up in deionised or distilled water at least 2 years and up to 3+ with two provisos the first that the Metabisulphite is fresh, second that you use HD plastic or glass bottles.

Ian
 
Thanks Ian for the tips. I used this bottle. I'm one of those folks that drink kombucha. https://goo.gl/images/M744Kq

I wish they have a 1 liter size.
 
Every time I'm in Japan, I always keep the little brown glass energy drink bottles. They work well storing pyrocat solution A, as well as solutions for kallitype printing...
 
Andrew O'Neill said:
Every time I'm in Japan, I always keep the little brown glass energy drink bottles. They work well storing pyrocat solution A, as well as solutions for kallitype printing...
Click to expand...

Seeing treasure in trash can be a good thing. I save my bladders from my box wines to store developers.
 
Chemists use the phrase "Like dissolves like." Which means that polar solvents like water dissolve inorganic compounds while nonpolar ones like glycol dissolve organic ones. One of the reasons that I dislike these glycol based developers is that the glycol severely limits what will dissolve in it. This in turn limits their composition. For example it would be nice if they could contain bromide. Thus metabisulfite will not dissolve in glycol to any extent. That's why I stopped looking into them some years ago. Adding water to a glycol developer is defeating their purpose that is a waterless concentrate.
 
When mixing in glycol, the Pyrocat-HDC recipe is recommended (from the website):

B. Pyrocat-HDC (Solution A mixed in glycol)
Stock A
Propylene Glycol at 150F 750ml
Pyrocatechin 50 g
Phenidone 2.5g
Ascorbic Acid 4.0g
Propylene Glycol to 1000ml

Pyrocat-HDC gives almost identical results as Pyrocat-HD with most films and development methods.

And yes, you do not need any heat and no water.
Measure it out, pour it all into a bottle, add the glycol and then gently turn upside down once or twice a day to mix up the stuff on the bottom.
It will dissolve in a couple of days.
 
Hey thanks for the recipe. I noticed there's no potassium bromide and no Sodium Metabisulfite. Are those the culprits that didn't dissolve into the glycol. Do I have to change development times with Pyrocat HDC?
 
Good one. HDC Is my go to developer for years and prefer the distilled water over the glychol because of the cleaner mixture but what ever floats your boat. Also I have found no different times over HD vs HDC.
 
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dances_w_clouds said:
Good one. HDC Is my go to developer for years and prefer the distilled water over the glychol because of the cleaner mixture but what ever floats your boat. Also I have found no different times over HD vs HDC.
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Great! Thanks for the info. I'm slowly starting to use Pyrocat HD. I like the look of PMK Pyro, but it's at times unpredictable. I'm particularly interested in stand developing with Pyrocat.
 
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