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mdm
6-Jun-2010, 18:21
I notice that of all the pyrocat formulas Pyrocat M looks to be the simplest and least expensive. All that is required over what can be had at a brewing supply shop is a little Catechol and a very small amount of Metol, both of which are very inexpensive. I think that a pound of Catechol and a lifetime supply of metol comes at a similar price to a 50l HD kit. A very attractive option to me because of the high cost of shipping stuff here, the simplicity of the formula and the convenience of never running out.

Will it give similar results to what I have come to expect from Pyrocat HD? HD is bombproof. It is so forgiving and easy to use and what I specially like about it is the speed gain from minimal agitation development. I am very sloppy with bellows factors and exposure and it just works every time anyway. Even my seat of the pants night time exposures just worked.
Will it work ok for divided development if I think I have really cocked it up somewhere?
What will it be like with medium format film and 35mm?

Any help appreciated.

David

sanking
9-Jun-2010, 07:34
I notice that of all the pyrocat formulas Pyrocat M looks to be the simplest and least expensive. All that is required over what can be had at a brewing supply shop is a little Catechol and a very small amount of Metol, both of which are very inexpensive. I think that a pound of Catechol and a lifetime supply of metol comes at a similar price to a 50l HD kit. A very attractive option to me because of the high cost of shipping stuff here, the simplicity of the formula and the convenience of never running out.

Will it give similar results to what I have come to expect from Pyrocat HD? HD is bombproof. It is so forgiving and easy to use and what I specially like about it is the speed gain from minimal agitation development. I am very sloppy with bellows factors and exposure and it just works every time anyway. Even my seat of the pants night time exposures just worked.
Will it work ok for divided development if I think I have really cocked it up somewhere?
What will it be like with medium format film and 35mm?

Any help appreciated.

David


Pyrocat M will give very similar results to Pyrocat-MC. It is essentially identical to -MC but is mixed in water instead of glycol and contains sodium metabisulfite which is replaced functionally by ascorbic acid in -MC. Pyrocat M uses the same Stock B solution as -HD and -MC

Compared to Pyrocat-HD you should see a tad more acutance when developed with rotary processing (Jobo, BTZS tubes, etc). Film speed is slightly less than -HD but you probably won't notice the difference.

I am not sure how long the stock solution of Pyrocat M will last but you are probably safe with six months in a partially full bottle.

Sandy King

mdm
9-Jun-2010, 12:12
Thanks for kindly answering my question. It was a lazy one, I found what I was looking for on the pyrocat page and with a little searching. I will probably mix the MC formula, I discovered I have a lot of glycol in the workshop masquerading as tractor coolant. It cost me about the same as a 50l HD kit to order a pound of catechol and a little metol, so that is me sorted for a long time.

I had a bash with caffenol c on the weekend but found it rather foul and not inexpensive to mix. The results were good though a little granier than I am used to. May use it again sometime.

David

Lachlan 717
16-Jun-2010, 17:15
I am not sure how long the stock solution of Pyrocat M will last but you are probably safe with six months in a partially full bottle.

Sandy King

Thanks for the ongoing information, Sandy.

Quick question: What's the approximate shelf life for the stock Pyrocat-MC products (i.e. unmixed)?

Thanks in advance,

sanking
16-Jun-2010, 17:33
Thanks for the ongoing information, Sandy.

Quick question: What's the approximate shelf life for the stock Pyrocat-MC products (i.e. unmixed)?

Thanks in advance,

The Pyrocat-MC stock solutions will last several years if stored in glass bottles. If you buy in plastic containers best to move the solutions within a few months to glass.

Sandy

Ken Lee
16-Jun-2010, 19:15
Here's (http://www.pyrocat-hd.com/html/preservation.html) an article about how to extend shelf-life to the maximum, by storing your chemistry in wine bottles, and using an affordable wine bottle vacuum pump.

Lachlan 717
16-Jun-2010, 20:15
Here's (http://www.pyrocat-hd.com/html/preservation.html) an article about how to extend shelf-life to the maximum, by storing your chemistry in wine bottles, and using an affordable wine bottle vacuum pump.

Funny you should mention that, Ken.

I sent Sandy a PM this morning/evening asking about colour of the glass for the bottle, and if those vacuum things are any use?

Lord knows they're no use for wine for me. Why wouldn't you simply finish what you started?

Thanks for the link.

Bob Farr
9-Mar-2011, 18:43
Hello,

I have started using argon gas to prevent oxidation of photo chemistry. Got the idea when the argon is used to help prevent wine from oxidizing.

Bob

mdm
10-Mar-2011, 07:07
I just mix 500 ml at a time and use it up in 2 or 3 months. You could mix less if that is what you use. If you use dry sodium carbonate as part B there is no chance of using the same utensils used in part B in part A, therefore no chance of contamination.

evan clarke
10-Mar-2011, 10:27
I make a liter of MC at a time and store it in brown Nalgene bottles.. It lasts and lasts and lasts...EC