Here are a number of quick notes on Pyrocat-M, a variation of -HD. The formula given by Sandy King follows:
To mix Stock Solution A,
| Distilled water at 50°C | 750ml |
| Metol | 2.5g |
| Sodium Metabisulfite | 10.0g |
| Catechol | 50.0g |
| Distilled water to | 1000ml |
Stock Solution B is a 75% solution of Potassium Carbonate,
| Distilled water | 750ml |
| Potassium Carbonate | 750.0g |
| Distilled water to | 1000ml |
That’ll make a liter of stock solution each. I made up 100ml of each instead, dividing each amount by 10. The -M variation is supposed to add a touch of sharpness over -HD.
Solution A was easy to mix. Just add the various components in the order above. A slightly yellow solution resulted. Do be cautious when handling the Metol though. I experienced a mild irritation when mixing the powder, but it went away after scrubbing down. I have no problems with it in liquid form.
The Potassium Carbonate (K 2 CO 3) is tricky to store; my stock was packed in 250g sachets. It’s highly deliquescent, which poses a problem when partial quantities are used. There’s a slight vapor in the sachet now, but I don’t think it’ll adversely affect the rest of the stock. Sodium Carbonate is far easier to handle.
When mixed into solution, K 2 CO 3 appears to be rather cloudy, but it clears up in 30 minutes or so. That’s apparently normal.
I stored them in brown glass bottles with a stopper. Apparently shelf life is 6 months or so. Using it at 1:1:100 dilutions should yield 40 rolls. It’s extremely economical to use at around 10 cents a roll.
I developed a roll of Fomapan 100 in Pyrocat-M mixed to 1:2:100 dilutions as I prefer shorter developing times. 5m30s was a pretty good starting point, and produced rich negatives with good density. Looks like they’ll print easily. For Fomapan 400, 7 minutes works well for me.
06/19/06
Comment
Justin,
It is really nice to see someone sharing his receipe on the film developer. I was wondering if it is that simple to mix all the materials together as it was many years back when i was still a student doing chemistry practical. I try shopping around…and cannot find the right place to get the required materials stated above. Do u mind if I ask you for advice on getting the material? Thks a lot for the help. I will be waiting for your reply. If it is not possible..is okie. =)
— hls · 14 July 09 · #