Hey, I received a whole lot of old agfa brovira paper and I wanted to try them out and develop. Now my problem is I bought a packet of Kodak Professional Hypo Clearing Agent(502g/17.7oz) and have no clue how to mix it. I read on another thread here it is best to mix all of the powder, but then I would be stuck with 19litres/5gallon which I have to use within 3months or it wont be usable anymore. So I would just want to mix so I end up with 1L working solution. On the packet it says mix 15L water + 4L( I assume this is mixed with all powder in the package = 502g) to end up with 19L working solution. So is there a way to find the amount of powder(in gram) I have to mix with the amount of water to get 1L working solution. I would eternally grateful !

mm so I would have to mix 800ml water + 200ml(+amount of product in grams) = 1L working product, how the hell do I determine how much powder I need. Damn Kodak instructions..

Mohawk, if 502g will make 19 litres of working solution, then divide by 19 to get the amount for 1 litre, or 26.42g. Are you sure about the 19 litres of water for the entire load of powder? You might want to get on the Kodak website and see if you can locate this product's technical sheet for more instructions, or to verify what you already have. I hope this helps you. Paul

Hey Paul, Uh it's THAT simple, heh I'm embarrased.. It says on the bag it will make 19Litres(or 5 US gallons), so yes thats correct. (it says first make 15L, then add powder and fill up until 19, so it will be slightly less then 19 but yes, close) I already checked the website without any luck. Well thank you very much, I can start experimenting with FB paper now !

Does HCA really have a three month shelf life? I always thought that its useful life was based upon the number of prints 'processed' in it. :confused:

hm well it says so on the package(for mixed working solution), but maybe it's just kodak's way of selling abit more

It's simple. The package directions are to make a stock solution. Extreme precision with this stuff is gross overkill, and 1L is close enough to 1 quart to not matter. If I recall correctly, my supply of HCA is measured in US gallons and quarts. Start with about 3L of water at the recommended temperature and mix ALL the powder into that. Top off with cold water to 4L. That's your stock solution. For use, take 1 part of stock solution and dilute it with an additional 4 parts water. That's your working strength solution. Use it once and discard. So if you want to make only 1L of working strength solution you need only enough powder to make 200ml of stock solution. Divide the net weight of the HCA package by 4 to get the weight of the chemistry needed for 1L of stock solution, that is 500/4=125 grams. Now for 1L of working solution you only need 1/5 of that amount since the usual dilution is 1+4 for a total of 5 parts. Now do 125/5=25 grams. That's how much powder you need to make 1L of HCA working solution. This is basic arithmetic and you should know how to work the numbers. If you don't, go complain to your local school board because they've failed you. The stock solution will last 3 months in a completely full and tightly stoppered bottle. Displacing the air with an inert gas in a partially full bottle qualifies as a completely full bottle.

Or buy marbles [http://www.moonmarble.com/p-794-game-boulders-1.aspx] and put marbles in to displace the air. By the way it does make the bottle very heavy towards the end. Steve

An effective (and inexpensive) HCA solution can be made by dissolving 20 grams of Sodium Sulfite in a liter of water.

I would never do it with developers but if there was any chemistry I would be tempted to divide up in the powder form and mix just a part it would be HCA. Pretty simple stuff as far as published formulas say.

Likely the OP has a very homogenous mix there though I'd be tempted to dump it in a bowl then stir and mix anew. For 20 grams average a few spoonfuls using a kitchen scale, note spoon size and filling; level or ? At time of use spoon up a fresh hca. Dan