View Full Version : Pyrocat HD Kit Impossible to Reconstitute?

Andre Noble
15-May-2004, 10:11
I just tossed the first of two 10L Pyrocat HD kits I ordered from Photo formulary because I messed the first up trying to mix it.

0.2 grams of Phenione? I can only pray some made it into the bottle.

Is there a secret to consistently mixing these tiny Pyrocat HD kits up?

Does someone sell a pre-mixed kit?

Dean Cookson
15-May-2004, 10:17
Bostick and Sullivan sells an liquid kit. I just used it myself for the first time a couple nights ago. The negatives look great despite the transfer cog on my Jobo breaking halfway through the pre-soak...

Ken Lee
15-May-2004, 10:28
Is there mention of it on their web site ? I have purchased PMK from them in liquid form, but I can't find any reference to Pyrocat HD on their site.

Peter Witkop
15-May-2004, 10:30
I use pyrocat-hd mixed from the same photographers forumulary kit you're using, I always try to be very care full to get all the chemicals into the bottle, and not spill any. So far I've mixed a few batches and haven't had any consitancy problems. I didn't realize Bostick and Sullivan sold liquid kits though, that would be a bit easier. Might be worth trying those if the price is similar.


Frank Lahorgue
15-May-2004, 10:31
I've used both kits -- Formulary and B&S -- and much prefer the B&S since it is delivered in liquid form. Mixing the stuff up is not easy. The one thing to remember is that the B&S kit solution B is 75% while the formulary is 100 grams to 100 ml. Somewhere Sandy King said to add 15% to developing time for the B&S kit. My results with both kits were indistinguishable.

Good Luck.....................

15-May-2004, 10:53
Something I can help with.

If you are going to mix dry chemicals it is best to have a beaker with a wide enough mouth to accomodate the whole top of the envelope. Bottles are a PItA. Since you are adding water to the mix any way use some of the water to rince the remaining chemicals from the bag. becareful not to splash but you should be wearing gloves to mix chemicals anyway. This is easy and as long as you are craeful not to exceed the final amount of water all of the chemical gets into the beaker. When finished transfer to you bottles.

Here is a cheap source of good beakers.


Dean Cookson
15-May-2004, 11:04
It's not on their website, as far as I can tell, and it's not in the online version of their catalog. They really do a pretty good job of keeping it secret... It's in the latest version of their printed catalog though. If you call them, they'll admit they have it...

15-May-2004, 11:05
Melody told me in an email that they Bostick and Sullivan had Pyrocat-HD for sale in a liguid but it has not gotten to the web site yet. You can order it over the telephone at this time.


Andre Noble
15-May-2004, 14:20
Good useable info here. Thanks.

Second question regarding the Pyrocat Solution B (Potassium Carbonate), mine has quickly come out of "solution" and seperated into components. Is it normally a suspension like this, or is it suppose to stayed dissolved in the H20?

Mike Troxell
15-May-2004, 15:27
I saw the Pyrocat liquid kits on B&S several days ago. The link to the Pyrocat listing is http://bostick-sullivan.com/commerce/aa_41.htm. For some reason its listed on the page you reach by clicking on the "Pyro Rollo Solution A" link under Alternative Photographic Process Chemicals.

15-May-2004, 15:38
"Second question regarding the Pyrocat Solution B (Potassium Carbonate), mine has quickly come out of "solution" and seperated into components. Is it normally a suspension like this, or is it suppose to stayed dissolved in the H20?"


No, that is not normal. Once the potassium carbonate is dissolved in water it should stay in solution at normal room temperature indefinitely. I have 75% Stock B solutions on hand that are several years old.

However, I think your working solution will give good results so long as you shake vigorously the B solution before adding it to the working solution.

Andre Noble
15-May-2004, 16:12
Sandy, thanks for that input. Will shake before use, and also be more careful mixing it in first place (originally, I added the water to a 100ml volumetric flask full of it - took 1 hour to sort that mess out. Duh!!)

PS, Mike is right it's available here also:


John D Gerndt
15-May-2004, 18:41

I too have problems with the Photographer's Formulary kit solution B. I just double the dilution and then double the B volume in my use. As to the tiny 0.2 grams of Phenione, I wish it would come in a pellet, but rinsing out the bag IS a good idea.


15-May-2004, 21:51
My solution B seperated too. Sounds like it is a common problem. I am glad to hear that shaking it before use is alright.

16-May-2004, 22:22
The Pyrocat-HD formula calls for a Stock B solution that is a 75% solution of potassium carbonate. That is what you get if you mix 100 g of potassium carbonate in 100 ml of water (makes a total of about 130 ml), or if you mix 75 g of potassium carbonate in water to make a total of 100 ml of Stock B.

I am not absolutley sure why the Formulary kit does not mix well. I suspect it is because the packet contains 100g of potassium carboinate and the directions say mix this in water to make 100 ml of Stock B. If so this makes a 100% stock solution, quite a bit stronger than my formula. I sent a message to Bud at Formulary about the issue but don't know if he has corrected the problem. In any event, the solution is to just add about 30 ml more of water to the Stock B solution to make a total of about 130 ml of Stock B.

Andre Noble
17-May-2004, 04:05

FYI, The Formulary Instructions read:

Part A: "Water to make 100ml"

Part B: "Water to make 100ml"

Thanks for the tip on the part B.

E. U. Eichhorn
17-May-2004, 08:23

The times you have at unblinkingeye.com are for the 75% solution, correct? Someone above says something about increasing development by 15% if using the 75% solution, which seems wrong if the times you have given are for the 75% solution.

However, I did do a roll of FP4+ 135 with EI of 100 in pyrocat-hd at 1:1:100 for 8 minutes @ 70degrees for non-UV printing and the negs came out pretty thin. These were developed using an earlier batch of Pyrocat-HD from PF that had the 100% solution B. So, maybe you must increase 15% development time when using the 100% solution B?

I just mixed a 500ml kit last night I received from PF. The instructions did have the B solution at 100%. I increased the amount of water to make it 75% and mixed by adding very very s l o w l y and it completely dissolved with no precipitation problems after sitting all night.


Frank Lahorgue
17-May-2004, 08:32
Oops -- I should have been more clear. I added 15% to my own times when switching from PF to the B&S kit, not to Sandy's. I was indeed trying to use a 100% solution B by following the PF instructions.

17-May-2004, 10:30
All of the recommended development times I have provided are based on the use of a 75% Stock B Solution of potasssium carbonate. I may have suggested at some point that one might need to reduce development times a slight amount if using the Formulary kit, and minus10-15% is about what I would try, but bear in mind that I have never actually worked with the kit so this is just a ball-park suggestion.

The most recent tests I did with Ilford FP4+ and Pyrocat-HD, 1:1:100 dilution, indicate that a development time of about seven minutes at 72 degree F, with rotary processing, should give enough contrast for printing on a #2 silver paper, with subjects of normal contrast. You would probably need to increase times slightly for VC papers by about two minutes. And if you are using other than constant agitation this needs to be factored in as well.

Thin negatives can result from both under-exposure as well as under-development, but the former is by far more common than the later in my experience.

Andre Noble
17-May-2004, 17:39
Regarding thin FP4+ Negs, I agree, probably due to underexposure. I would try rating the FP4+ in Pyrocat HD at ASA 40.

I have not used Pyrocat but FP4+ in Pyrocat HD and FP4+ in Wimberly WD2D+ (which I do have experience with) are supposedly similar.

I found the true film speed of FP4+ in WD2D+ Pyro is ASA 40 despite claims that WD2D+ delivers true film speed.

Yes, every film manufacturer and developer manufacturer likes to rate B&W film speeds too high. This serves their marketing strategy (they think), but they don't calculate the loss of a customer who quits using their product early because they are not getting technically successful results.

Andre Noble
17-May-2004, 21:50
PS: My Part B is now completely into solution! Yeah! I added the additional 30ml Sandy recommended to make a 75% stock B solution out of the Photographer's Formulary kit, and all's cool now with my part B.