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Old 20th February 2009, 10:15 AM
Len Scapoff Len Scapoff is offline
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Has anyone tried Geoffrey Crawley's home brew as given to the world in the AP of 13/9/08 (about the last article of interest to film photographers in that mag)?
I suppose it's a close relative of Paterson's extinct FX-50.How close is it to Xtol?
Anyway, I was thinking of trying it as it claims to be eco-friendly (the article was headed "Going Green") and solution A apparently keeps indefinitely, which gets over the problem of developer keeping properties when you've got a small through-put of films.
As I've never tried home brew before I have a question. Crawley's formula for solution A is
Potassium carbonate:20g
Sodium bicarbonate:1.5g
Sodium sulphate:25g
Sodium metabisulphate:12g
Water to 1000ml

There is no mention of temperature of water for mixing the ingredients. Can anyone (apart from GC who I don't know how to contact) advise? (Perhaps this is a question for 'Ask Les')

Len

PS Solution B is
Sodium L-ascorbate:1.3g
Phenidone:100mg(0.1g)
which is added to 1000ml of A, diluted 1:9, to make the working solution.
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Old 20th February 2009, 11:08 AM
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I've not tried this particular recipe but the general process is to start off with around 70-75% of the water heated to 50-55 degC. Mix the chemicals into the water in the same order as listed in the article (the order is sometimes important for everything to dissolve easily). Each chemical should be completely dissolved before adding the next. Top up with water to make a total of 1 litre.

Have fun, Bob.

[Just noticed - you have no amount given for the water for solution B.]
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Old 20th February 2009, 11:24 AM
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Solution A is only the alkali - certainly will keep forever, as long as it doesn't evaporate! Solution B will heep a long time, but the phenidone is the limiting factor in it's longevity. The Ascorbate is vitamin C - an excellent developer, but not good on it's own - needs to be combined with another developing agent, and it works well with phenidone. Ascorbate is an oxygen scavanger and the dev will not last long once mixed. It all mixes at 20 degrees C. Solution B is also made up to 1 litre.
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Old 20th February 2009, 02:53 PM
Len Scapoff Len Scapoff is offline
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Default Fx-55

Thanks for the helpful replies, Bob and Peter. I'd better try to clear up what I failed to explain properly. B is not really a solution. You dilute solution A at 1:9 to make up 1000mls, and then add the dry chemicals to make 1 litre of the working solution. The advantage seems to be that you have a solution A which has a very long life, and when you want some developer you add the ascorbic acid and phenidone. The disadvantage seems to be that you have to make up 1000mls when you probably only want 300 or 500mls (the working solution has a life of about 36 hours). I'm guessing that smaller volumes of A would mean impractically (for measuring purposes) tiny amounts of phenidone.
I'm still confused about the temperature for mixing A. Bob suggests a much higher figure than Peter's 20.

Len
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Old 20th February 2009, 02:57 PM
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20 degrees is pretty universal. There has to be a real reason to change much from that. Yes, the problem with making smaller amounts is measuring accurately. You can't even make a percentage solution with Phenidone because it won't keep.
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Old 20th February 2009, 03:40 PM
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I think the confusion is that Bob is talking about the initial making up of the stock solution A while Peter is talking about the final diluted working solution that you use to develop the film.
Bill
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Old 20th February 2009, 05:26 PM
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Quote:
Originally Posted by Len Scapoff View Post
Thanks for the helpful replies, Bob and Peter. I'd better try to clear up what I failed to explain properly. B is not really a solution. You dilute solution A at 1:9 to make up 1000mls, and then add the dry chemicals to make 1 litre of the working solution. The advantage seems to be that you have a solution A which has a very long life, and when you want some developer you add the ascorbic acid and phenidone. The disadvantage seems to be that you have to make up 1000mls when you probably only want 300 or 500mls (the working solution has a life of about 36 hours). I'm guessing that smaller volumes of A would mean impractically (for measuring purposes) tiny amounts of phenidone.
I'm still confused about the temperature for mixing A. Bob suggests a much higher figure than Peter's 20.

Len
20C is the normal temp for processing but a higher temp is used to get the chemicals into the concentrated stock solution.

Also, you list sodium sulphate - should that not be sodium sulphite?
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Old 20th February 2009, 05:46 PM
Len Scapoff Len Scapoff is offline
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Bob, You're quite right. It should be sodium sulphite. Apologies.

Len
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Old 20th February 2009, 05:47 PM
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mixing temp should be as cool as possible but warm enough to dissolve the chemicals easily. Some require warmer temp, others don't. Ilford seems to use 40c for all its developers. In this case, I'd try 30C and if all dissolves easily, then next time try 20C. But if it won't disssolve easily, then just stand it in a hot water bath to raise temp to 40C or so and see what happens.
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