Kodak Hypo Clearing Agent

RalphLambrecht · Sep 4, 2012

that seems very logical. i was thinking that a mixture of different salts may be more efficient the formula is closer to actual sea water, but i have notests to back this up yet.

Bob Carnie · Sep 4, 2012

Ralph - I ordered some Sodium Hexametaphosphate today after seeing your post , I will follow your formula, basically same as what Ian Grant proposed, but I think
the hard water in my town lately may be giving me this result and the SH will soften it a bit if I am reading between the lines correctly.
I can only attribute the white scum to the clearing bath as all my other chem's are tried and true for over a large amount of printing sessions.

RalphLambrecht · Sep 5, 2012

hca is about the simplest chmical to mix from scratchand a great way to get into mixing your own process solutions, just give it a try.all you need is a scale and some measuring cups.

Bob Carnie · Sep 17, 2012

Ralph - added 10 grams of Sodium Hexametaphosphate and problem solved... Ok so what just happened I assume my water in August took a turn??

Also I added the SH in hot water and part of it did not dissolve and turned into a hard gooy mass.. should this stuff not be mixed with hot water??

RalphLambrecht said:
hca is about the simplest chmical to mix from scratchand a great way to get into mixing your own process solutions, just give it a try.all you need is a scale and some measuring cups.

madgardener · Sep 17, 2012

I use the Legacy Pro brand at Freestyle. Its a good product and not that expensive.

I don't want to get into a money argument with the members here, but for some of us, even a penny can make a huge difference.

Roger Cole · Sep 17, 2012

I've used the Legacy Pro brown toner and Rapid Fixer. It's fine. But for many of their items the price difference is, well, quite small. If that matters to you it's a fine alternative. But if price really matters on hypo clear, but a bulk jar of sodium sulfite and mix your own. You probably won't get the scum Bob does. If you do, add other ingredients per above.

Dave Krueger · Jul 11, 2013

In comment #21 Ralph os talking about 20g per liter of water, whereas Bob Carnie, in comment #23 is talking about 200g/liter. That's a 10 to 1 difference in concentration. Which one is correct? It seems to me like the 20g/liter is correct for the working solution.

Maybe Bob's experience with the white scum is due to his using a much higher concentration.

I know this is an old thread, but I've been researching the idea of mixing my own HCA and throwing it away after the printing session whenever I do fiber prints.

Vlad Soare · Jul 11, 2013

20 grams per liter is correct.
It doesn't have to be very precise. Two tablespoons per liter will be just fine.

Tim Moore · Oct 29, 2021

fschifano said:
Don't sweat it. You can make your own hypo clearing agent very cheaply and easily in whatever portions you need. The formula from unblinkingeye.com follows, but you can do without the sodium bisulfite. Scale the formula down to make only as much as you need to last a week or so and you're good to go.

From unblinkingeye.com

Hypo Clearing Agent

Water (125º F) . . . . . . . . . . . . . . . . . . . 750 ml
Sodium Sulfite . . . . . . . . . . . . . . . . . . . 200 g
Sodium bisulfite*. . . . . . . . . . . . . . . . . . . . 2 g
Water to make . . . . . . . . . . . . . . . . . . . . . 1 liter

Dilute 1:9 for use.

thanks very much for this !

RalphLambrecht · Oct 30, 2021

fschifano said:
Don't sweat it. You can make your own hypo clearing agent very cheaply and easily in whatever portions you need. The formula from unblinkingeye.com follows, but you can do without the sodium bisulfite. Scale the formula down to make only as much as you need to last a week or so and you're good to go.

From unblinkingeye.com

Hypo Clearing Agent

Water (125º F) . . . . . . . . . . . . . . . . . . . 750 ml
Sodium Sulfite . . . . . . . . . . . . . . . . . . . 200 g
Sodium bisulfite*. . . . . . . . . . . . . . . . . . . . 2 g
Water to make . . . . . . . . . . . . . . . . . . . . . 1 liter

Dilute 1:9 for use.

is there possibly a mistake? My formula calls for only 20g of sodium sulfite!

tezzasmall · Oct 30, 2021

RalphLambrecht said:
is there possibly a mistake? My formula calls for only 20g of sodium sulfite!

The formula you show Ralph, is for a concentrate that has to be diluted 1:9, as mentioned in the formula as 'Dilute 1:9 for use'.

As for the 20g of sodium sulfite per litre that you use, I don't weigh mine but use a one tablespoon measure, which gives me the 20g per litre of working solution.

In fact, in this much read link, it is quoted as a heaped teaspoon per litre being used, which having just weighed some, it is 16.5g, so not far off of what we use.

http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=296&garpg=5

(Second paragraph from the bottom = under 'Hypo Clearing'.)

The link quotes, 'For scratch mixers, a 2% solution of sodium sulphite (about a heaped teaspoon in a litre of water – measurement accuracy is not critical) works well.'

Terry S

JPD · Oct 30, 2021

What times do you use for your Sodium sulphite solution? I use 3 minutes for film and 3-4 minutes for fibre based paper.

Kodak Hypo Clearing Agent

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