Interested in trying Pyrocat - HD or MC

[Mark Barendt]

The MSDS sheet link on the on the page I linked to above leads you to the info, they use propylene. I don't know if the type makes any difference.

[sanking]

I understand Pyrocat HD in Glycol but my question is which type of glycol, dieythylene, propylene, polyethylene? does it make any difference?

I have used both diethylene and propylene glycol to mix the Solution A stock solution of Pyrocat-HD and -MC. Both work fine for the purpose.

Sandy

[hmf]

Pyrocat-HD and Ilford HP-5+ is a match made in heaven. Have been using it for several years with excellent results.

Previously used Ilford DD-X and often blew out the highlights. Almost impossible to blow out highlights with a pyro developer.

Not to worry. The stain is very faint. Looks like a tobacco stain. Very little effect on VC printing.

Continuous agitation for the first minute. Then, agitate for 15 seconds each additional minute until the time expires.

For longer shelf life, purchase Pyrocat-HD in glycol from the Photographer's Formulary and use the standard dilution of 1:1:100. A little goes a long way

Try it. You'll like it.

I am interested in trying this combo for Na2 pt/pd printing. My densitometer does not read UV, so I could use some starting points for experimentation with HP5+ and Pyrocat HD using tray development.

Thanks.

[Gem Singer]

hmf,

Ilford classifies tray development as continuous agitation. Not quite as severe as rotary development.

Start with 1:1:100 for ten minutes. Adjust development time up, or down, to suit your needs.

I have found that the kind of agitation used and the frequency of agitation has a greater effect on film contrast than temperature variations (68-75 degrees F).

[photobymike]

Been using Pyrocat HD Glycol for over a year and here are some my observations.

1. Use pipettes to measure. This stuff is so concentrated that being off a small amount effects your out come.

2. I presoak for 5 minutes at development temperature. I change out the water 2 or 3 times for the presoak. It is needed to wash away the halation barrier. This has always been important... use distilled water... the PH is slightly acid which is ok... tap water who knows what it is.....

3. Use rubber gloves when handling this substance. If you use it a lot, it can accumulate in your system and be toxic.

4. Use distilled water for mixing. I use distilled water for all of my photo chemicals anyway.

5. The negatives scan really well with my scanner V750 epson. I seem to have a longer dynamic range by at least one stop.

6. I use a Beseler roller for development... but it seems to like stand alone tank with moderate agitation...twirl the reels in my paterson tanks.....4x5 always are rolled....

7. Dilute your Stop Bath... to strong and you get pin holes. Use a stop bath to get the film ready for the acid in your fixer.. i use alkli fixer especially for T-grain films.. for an extra 3 minutes.

8. When you get ready to mix your developer. Roll your bottles of concentrate before using... there seems to be some separation and precipitate on the cap after sitting for a couple of days. Do not shake but make sure concentrate is mixed.

9. Because of the tanning (hardening effect) of the developer it seems the emulsion needs more washing than normal film.... i use very strong hypo clear (Orbit) for 2 minutes each in 2 baths with vigorous agitation.

10. I take the film off the reels and soak for 30 secs in Photo-Flo. Most important; I use distilled water to mix Photo-Flo. If you use regular water or tap water you will see a sledge or slim on your finished negs... The i use a very clean sponge to wipe away the excess Photo-Flo.

I do all of this and what i end up with is beautiful chocolate colored negatives that scan really well.

[Andrew O'Neill]

If you are a casual developer, mixing pyrocat-hd in glycol is beneficial. If you develop a lot, like on a weekly basis, don't bother. Just use water.

[Jay DeFehr]

Barry,

Pyrocat HD (or MC) can be made to keep better, even in water, than it does as formulated, simply by mixing it up at 5X the concentration:

Distilled Water (50 C) 70 ml
Sodium Metabisulfite 5 g
Pyrocatechin 25 g
Phenidone 1.0 g
Potassium Bromide 0.5 g
Distilled Water to make 100 ml

A 1:500 dilution of the above = 1:100 dilution of Pyrocat HD as formulated. Part B has no keeping issues and can be mixed as usual/ already highly concentrated, 75% potassium carbonate solution. The equivalent dilution would be 1:5:500, and results will be identical, but the concentrated stock solution A will keep much better. The 100ml formula above is equivalent to 500ml of the standard formula, will make 50 liters of working solution, and should last long enough to use up for even the most occasional photographer. Very active photographers who don't like to mix often can scale the formula up as desired.

You'd have to make up your own, as it's not sold this way, but if you're game, it might be worth your while.

[Cletus]

I've been using Pyrocat HD (Per Octogenarian's suggestion) with HP5 for a few weeks now. I seem to be having some trouble getting sufficient density with it and I'm getting frustrated. I don't know why this is. My first attempts with 8x10 tray processing was:

1:1:100 @ 20C for 18', agitation was "shuffle the stack" once per minute, about 15"/min. Negs were thin looking. HP5 exposed typically ~320.

Next attempts was even longer development, like 22'. I'm using these for pt/pd printing and at 20C, this seems to work out to about 50-100% overdevelopment. I figured if I went to extremes I could adjust from there. Kind of a butchered up 'outflanking' scheme. I still got thin negs. Instead of adjusting the temp up to Sandy's recommended 22C, I guessed longer development at 20C would equal out. Maybe not?

This morning I tried:

1:2:100 and 2:2:100 @ 22C for 10'. Same agitation scheme. Negs are better, but still not ideal, slightly thin. Funny thing is, a batch of four 4x5 negs looked better then the identically exposed 8x10 negs. Same everything, the 4x5s look much better. I suspect a possible problem with the shutter on my only 8x10 lens, but I haven't noticed any issues using XTOL or Rodinal with the same films.

This may not be enough info to make any judgement but the point is, I seem to be having more trouble than I should with this supposed very versatile developer. Anyone have experience anything like this?

[evan clarke]

Originally posted by Sandy King, his excellent work.

Pyrocat Versions and Mixing Directions
Pyrocat – Versions and Mixing Directions

I am attaching mixing directions for various versions of Pyrocat, including –HD, -M, -P, -MC and -PC. I am indebted to Pat Gainer for his advice and recommendations for mixing the glycol based versions of Pyrocat, including Pyrocat-HD, -MC, and -PC.

Pyrocat-HD is the original Pyrocat formula and is still the most popular judging by sales and questions I get about it. The other formulas, which include Pyrocat-M and Pyrocat-MC, and Pyrocat-P and Pyrocat-PC are recommended primarily for rotary processing, where they tend to give slightly greater acutance than Pyrocat-HD.

All of the Pyrocat formulas are acutance developers that give good pictorial rendition when used at dilutions of 1:1:100 to 2:2:100 with normal agitation. When used at higher dilutions with reduced agitation they become high acutance developers with very pronounced adjacency effects. Pyrocat can also be used as a two bath developer. See instructions at end of this message.

Some of the characteristics of all of the Pyrocat variants are:
1. Good acutance.
2. Tight grain pattern with some grain masking from stain.
3. Lower levels of general stain, even with long development times, than most pyrogallol based developers.
4. Does not cause uneven staining or streaking when developed in Jobo.
5. Can be used with dilute solutions and minimal agitation for very pronounced adjacency effects and enhanced apparent sharpness.
6. Very inexpensive to use.
7. Stock solutions last a long time. A year or slightly more when mixed in water, and up to several years when Solution A is mixed in glycol.

All of the Pyrocat versions use the same Solution B, which is a 75% solution of potassium carbonate. It is possible to substitute a 20% solution of sodium carbonate but if you do so the working formula must be mixed at 5X the amount of Solution B. Thus, a dilution of One Part A + One Part B + 100 Parts water when using the 75% potassium carbonate solution would become One Part A + Five Parts B + 100 Parts water.


A. Pyrocat-HD (For one liter of Stock Solutions A and B)
Part A
Distilled Water (50° C) 750 ml
Sodium Metabisulfite 10 g
Pyrocatechin 50 g
Phenidone 2.0 g
Potassium Bromide 2.0 g
Distilled Water to make 1000 ml

Part B
Distilled Water 750 ml
Potassium Carbonate 750 g
Distilled Water to make 1000ml

Mixing Directions for Stock B.
1. Start with 700ml of distilled water.
2. Weigh out 750g of potassium carbonate and add the chemical very slowly to the water, with constant and rapid stirring. If you add the solution too fast, or don’t stir enough, it will be impossible to dissolve all of it in the water. As you add the chemical an exothermic reaction takes place and the solution will warm up appreciably.
3. Add distilled water to 1000ml.
Tests show that the Pyrocat-A stock solution is stable in partially full bottles for up to a year. If shelf life of longer than one year is desired I recommend mixing Stock A in glycol. Stock Solution B has indefinite shelf life.
Mixing one-liter of Pyrocat-HD Stock A solution in propylene glycol.

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 750ml of propylene glycol to about 150F in a water bath or hot plate stirrer.
3. Add the pyrocatechin to the warm glycol and stir until dissolved. Should take no more than about a minute.
4. 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 distilled water at about 120F. Stir until completely dissolved, and then add this solution to the propylene glycol solution.
6. Top off the solution with glycol to 1000ml.

Pyrocat-HD Stock Solution A, when mixed in propylene glycol, has a shelf life of several years.

B. Alternative Pyrocat-HDC mixed in glycol.
Pyrocat-HDC

Stock A
Propylene Glycol at 150F 750ml
Pyrocatechin 50 g
Phenidone 2.5g
Ascorbic Acid 4.0g
(Mix in the order noted and stir until dissolved)
Glycol to one liter.

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

C. Pyrocat-P (Solution A mixed in water)
Stock A
Distilled Water at 120ºF 750ml
Sodium Metabisulfite 10.0g
p-Aminophenol 5.0g
Pyrocatechin 50g

D. Pyrocat-PC (Solution A mixed in glycol)
Stock A
Propylene Glycol at 150F 750ml
Pyrocatechin 50g
p-aminophenol 5.0g
Ascorbic acid 4.0g
(Mix in the order noted and stir until dissolved)
Glycol to one liter.


E. Pyrocat-M
Stock A
Distilled Water at 120º F 750 ml
Metol 2.5g
Sodium Metabisulfite 10g
Pyrocatechin 50g
Water to 1000ml

Notes:

1. Mix the chemicals in the order given and stir until dissolved before adding the next chemical.

2. The use of the potassium bromide restrainer used in Pyrocat-HD is not needed with Pyrocat-P and Pyrocat-M because of the lower pH threshold of metol and p-aminophenol than phenidone.


F. Pyrocat-MC

Stock A
Propylene Glycol at 150F 750ml
Pyrocatechin 50 g
Metol 2.5g
Ascorbic Acid 4.0g


Mixing directions. Start with about 8ml of TEA at room temperature and a spoonful of water. Now add 2.5 g of metol and stir to make slurry. This is eventually going to make a liter but you can start in a 1/4-liter cup. After the slurry gets a little more fluid, add 15-20 ml of some warm propylene glycol. Now you can transfer the metol slurry to the 750ml of warm propylene glycol and stir until dissolved. Now add 50 grams of pyrocatechin and stir until dissolved. Add 4.0g of ascorbic acid and stir until dissolved. Add glycol to one liter.

Alternative mixing directions. Heat the glycol to about 250 F and all of the chemicals will readily go into solution with no water required. Mixed this way the solution will be even longer lived. Add glycol to one liter.


Pyrocat as two-bath developer. Many two-part developers can be used as two-bath developers. Barry Thornton's Diaxactol was originally marketed as a two bath developer, though apparently not a very good one as it was later re-marketed as a single bath developer.

Pyrocat-HD can also be used as a two-bath developer with excellent sharpness. For this I recommend a 1:10 dilution of both Parts A and B, with solution temperatures at 75F.

1. Water bath for three minutes. Not necessary for most films but I recommend the water bath for Fuji Acros, Tmax-100, Delta 100, and most fine grain films of ASA 100 or less.

2. Six minutes in Part A, with two inversions at the beginning, and two inversions at the 1/4, 1/2 and 3/4 points of development.

3. Pour our Solution A and pour in Solution B. No rinse between. Initial agitation two or thee inversions, then two or three inversions at the 1/4, 12 and 3/4 points of development.

4. Pour out B, pour in water and leave for five minutes.

The purpose of the relatively long time in B and the final water bath is to allow developer exhaustion for maximum adjacency effects.

When used this way Pyrocat-HD is a high acutance compensating developer.

Pyrocat-HD negatives with the two-bath method described above have higher acutance than with one bath development and intermittent agitation.

Both Solution A and Solution B can be re-used several times within a three-four hour period but should be discarded at the end of a development session as they will go bad in about 10-12 hours.

[Gem Singer]

Phil,

Have you printed those "thin" negatives yet?

When comparing negatives developed in MQ or PQ developers (D-76, Xtol, etc.), negatives developed in Pyrocat-HD always look slightly thin.

However, they scan and print very nicely.