Pyrocat HD in Glycol, Step bt Step Mixing Instructions

[Andre Noble]

Is there anyone who can post here, as a resource, A step by step mixing instruction for a Pyrocat HD stock solution A preparation in glycol, inclucluding each component chemistry amounts, the order of mixing, and the recommended glycol temperatures at each stage?

(Hopefully, your recipe will be for a Pyrocat HD stock A solution equivalent in development action to the standard Photographers Formulary/Sandy King Pyrocat HD stock A solution.)

There are various tidbits how some do this on APUG and Paula And Michael's Azo website, but nothing comprehensive enough to go from step one to finish with confidence.

Thanks in advance for any and all input.

[Jay DeFehr]

Andre,

I can provide detailed instructions for Hypercat A solution:

Add 10g catechol and .5g ascorbic acid to 90ml room temp glycol, and heat with stirring until dissolved. That's it!

This solution will be about 2X as concentrated as Pyrocat HD, and can share the same B solution. If you want to make a working solution roughly equivalent to a 1:1:100 dilution of Pyrocat HD, use a 1:2:200 dilution of Hypercat.

Jay

[sanking]

Is there anyone who can post here, as a resource, A step by step mixing instruction for a Pyrocat HD stock solution A preparation in glycol, inclucluding each component chemistry amounts, the order of mixing, and the recommended glycol temperatures at each stage?

(Hopefully, your recipe will be for a Pyrocat HD stock A solution equivalent in development action to the standard Photographers Formulary/Sandy King Pyrocat HD stock A solution.)

There are various tidbits how some do this on APUG and Paula And Michael's Azo website, but nothing comprehensive enough to go from step one to finish with confidence.

Thanks in advance for any and all input.

Andre,

You will find instructions for mixing Pyrocat-HD in Glycol in the following thread on APUG.

http://www.apug.org/forums/showthrea...ocat-HD+glycol

If you are going to use Glycol you might might also want to consider the Pyrocat-MC formula. See
http://www.apug.org/forums/showthrea...ight=Pyrocat-M

Both formulas mix easily and readily following the instructions.

Sandy

[Andre Noble]

Sandy and Jay, thank you very much. Sandy, I reproduced your instructions from that link here. Now THIS looks like it will be fun (while making me feel like a real photographer in the Mathew Brady tradition.)

Per Sandy King:

"MIXING STOCK SOLUTIONS OF PYROCAT HD (PART A) WITH GLYCOL

On mixing Pyrocat-HD in Propylene Glycol. As many of you know, mixing Stock Solution A of Pyrocat-HD in Propylene Glycol provides stability of the stock solution on the order of years, similar to HC-110. Here is a very safe way to do this, measured for the 1000ml kit.

1. Weigh out all of the chemicals for Stock A. 50.0g of pyrocatechin, 10.0g of sodium metabisulfite, 2.0g of phenidone and 1.0g of potassium bromide.

2. Pre-heat in a water bath 750ml of propylene glycol to about 150F.

3. Add the pyrocatechin to the glycol and stir until dissolved. Should take no more than about a minute.

4. Now add the phenidone and stir. Should dissolve completely in about a minute.

5. Add the bromide and sodium metabisulfite to about 50-75ml of hot water at about 120F. Stir until completely dissolved, then mix with the propylene glycol solution.

6. Top off the solution with glycol to 1000ml..."

Thanks again Sandy

[sanking]

Andre, and anyone else interested,

I provided mixing intructions to the folks at PF for Pyrocat-HD and Pyrocat-MC in glycol and they mixed up liter bottles of the two solutions for me today. This afternoon I exposed three sheets of 5X7 fillm identically and tonight developed one in the original Pyrocat-HD in water, one in Pyrocat-HD in glycol and a third in Pyrocat-MC.

The first two are virtually identical in density, contrast range and stain color and density, as I would have expected from my own comparison tests. That means that when using the glycol based -HD any development data one might have worked out for the water mixed version can be used without any modification. The Pyrocat-MC negative has a slightly higher visible contrast range, and the stain is more intense, so some slight decrease in development times should be anticipated when using it.

Also, I asked Bud about date stamping the developer and there will be no problem in doing that. He did mention, however, that the Pyrocat-HD kits they have been mixing in the past are generally sold withing two weeks of when mixed.

In any event I imagine PF will be offering both of these kits for sale within a fairly short period of time. Check with them for details as to exact date and pricing.

Sandy

[Andre Noble]

Sandy, that is good news, all. Perhaps Pyrocat in glycol will become the new standard.

...

He did mention, however, that the Pyrocat-HD kits they have been mixing in the past are generally sold withing two weeks of when mixed.


Sandy

I know that is the case for their Pyrocat HD in water kits, but certainly not the case for their Wimberly WD2D+ kits, many of which sit on dealer shelves after Photographers Formulary ships them.

Sandy,

Thanks again for diverting your time to look into all this.

[sanking]

Sandy, that is good news, all. Perhaps Pyrocat in glycol will become the new standard.




I know that is the case for their Pyrocat HD in water kits, but certainly not the case for their Wimberly WD2D+ kits, many of which sit on dealer shelves after Photographers Formulary ships them.

Sandy,

Thanks again for diverting your time to look into all this.

Andre,

Just one more bit of information. All of the liquid kits from Formulary have a batch number that indicates when the kit was actually mixed. This goes back for years. So if you have a question about the acutal date of mixing of either your Pyrocat-HD or Wimberly WD2D+ kit you can contact Formulary with the batch number on the kit to find out on what date it was actually mixed.

Sandy

[steve simmons]

What is it about this formula that makes it so unstable that batch dates, special mixing, etc, seems necessary. The old ABC pyro was also unstable, the B solution would change over time, but I thought the newer formulae improved on this problem. I have not heard of this stability and dating problem with W2D2 or the plus version or with PMK.

steve simmons

[Jorge Gasteazoro]

Would you leave it alone? Are you going to come and mess this thread too? There is nothing unstable about Pyrocat, it lasts longer than PMK, but people want to make large quatities and be able to store them for years, this is the capability that glycol gives to Pyrocat. You are really becoming tiresome!

What is it about this formula that makes it so unstable that batch dates, special mixing, etc, seems necessary. The old ABC pyro was also unstable, the B solution would change over time, but I thought the newer formulae improved on this problem. I have not heard of this stability and dating problem with W2D2 or the plus version or with PMK.

steve simmons

[steve simmons]

Given all the threads about Pyrocat and the mixing and stability probloms this is a fair question. PMK is very stable. I have kept the A and B solutions going for years just adding a new batch to what was about to run out. This is one of the qualities of the PMK and W2D2 formulae. I hope the Pyrocat group won't try and divert attention from the problems by engaging in personal attacks. The question I asked is a fair one and not personal. Lets keep the answer on a high level and not drop into personal insults.

steve simmons