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  1. #11
    ic-racer's Avatar
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    Quote Originally Posted by Roger Cole View Post
    You can also get various liquid concentrates that will last longer than the three months and just mix as needed. I use Heico Perma-Wash.
    Same here. The Perma Wash is nice because the concentrated solution lasts a long time. I mix it one-shot and toss it.

  2. #12
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    I'm curious why the expiry time of Kodak HCA is so short. It seems that a solution of simple salts (right?) should last indefinitely. Any thoughts?
    If you are the big tree, we are the small axe

  3. #13

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    I have used HCA a long time after the ''Expirey Date'' without any detriment,I think they vjust want us to spend more money,Richard

  4. #14

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    Floaters in Perma Wash

    Quote Originally Posted by Roger Cole View Post
    You can also get various liquid concentrates that will last longer than the three months and just mix as needed. I use Heico Perma-Wash.
    I tend to get some floaters in this solution after about a month and a half. I have been debating switching back to HCA because of it. Not sure what is causing this, but it has ruined a roll of film. Now I check the solution before I pour it in the tank.

  5. #15
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    Quote Originally Posted by markrewald View Post
    I tend to get some floaters in this solution after about a month and a half. I have been debating switching back to HCA because of it. Not sure what is causing this, but it has ruined a roll of film. Now I check the solution before I pour it in the tank.
    Half of a cotton ball stuffed into the neck of a funnel makes a good filter for particulates.

  6. #16

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    [QUOTE=john_s;1162805]It is not at all critical. You can divide the powder./QUOTE]

    Thanks for all of the info! I do want to use the packet of Kodak HCA that I currently have, so I'll take a stab at dividing the powder. Another of the reasons I liked KHCA was the low cost, as I have only a limited amount of money that I can spend on photography each month. Someone mentioned Heico Perma Wash and at B&H, it costs about twice what HCA does. Two packets of KHCA ($11.90) would make 10 gallons of working solution and one quart bottle of Heico Perma Wash ($24.95) makes 11 gallons of working solution. That's what I meant about the other options at B&H being out of line, price-wise. There's even a brand of HCA (Clayton) that sells for $2.95 per one gallon packet, but the minimum order is 20 packets ($59)! Huh? After using this Kodak HCA packet, I'll probably try Legacy Pro or mix my own.

  7. #17
    Roger Cole's Avatar
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    I understand cost savings to an extent. $24.95 for 11 gallons is $2.26 and a fraction per gallon. If you use 16 oz (generous - my plastic tanks except the Jobo take more like 12 oz and my steel and smallest Jobo only 8 oz) per 35mm roll that's twenty eight cents per roll. If halving that cost to fourteen cents is significant then it seems paper would be impossible to afford.

    Don't get me wrong, I've been a student, and I've made test strips on the tiniest piece of paper I thought I could get info from (often false economy, I know now and sort of knew then) and so on. But fourteen cents a roll?

    EDIT: Oh yes those costs assume you don't reuse it. With a capacity of 20 rolls per liter that's roughly one fifth of those costs. Round down to one fourth and the difference becomes that between seven cents a roll and three and a half cents a roll. I just can't believe that saving three and a half cents a roll is important to anyone.
    Last edited by Roger Cole; 04-05-2011 at 09:58 PM. Click to view previous post history.

  8. #18
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    I agree with others that HCA is probably one of the easiest photographic chemicals to mix yourself. I can offer the attached formula, which I use for years.
    Attached Thumbnails Attached Thumbnails HypoClearingAgent.jpg  
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
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  9. #19
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    Quote Originally Posted by holmburgers View Post
    I'm curious why the expiry time of Kodak HCA is so short. It seems that a solution of simple salts (right?) should last indefinitely. Any thoughts?
    Sodium sulfite has a limited life in solution. It reacts with the oxygen in the water and oxidizes to sulfate (which, incidentally, is what makes it useful as a preservative in developers).

  10. #20

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    Quote Originally Posted by holmburgers View Post
    I'm curious why the expiry time of Kodak HCA is so short. It seems that a solution of simple salts (right?) should last indefinitely. Any thoughts?
    Because sodium sulfite (in solution) will sooner or later oxidise and become sodium sulfate. The later gives neutral solutions, as opposed to the mildly alkaline solutions that sulfite gives. So, from some point on, it's not as potent as a hypo clearing agent as it was when fresh. If you want something long lasting, then sodium carbonate is probably the best choice, something that Agfa proposed in their technical publications. If you want to stick to sulfite, then IMHO, it would be better to mix a 2% solution when needed and discard after the printing session. So, something like 20g of sulfite in water to make 1l is fine.

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