Hypo Clearing Agent

[justinphilip]

Hey guys. I am new here. I just got my chemistry so I can start developing my own film. I am having a question about one thing though. I got Kodak Hypo Clearing Agent and I am not sure how to mix a working solution for this. Does anyone here use this? The instructions are a bit confusing to me. How much of what do I need to use to make a stock solution? Or is there a way that I can go straight to making a working solution? Sorry if this is a dumb question. Thanks!

 

[david b]

IIRC, once you mixing the powder and water, you get the working solution.

 

[Michel Hardy-Vallée]

Put the whole pack in the required amount of water = stock solution.

Take one measure of stock, add four measures of water = working solution.

Discard working solution after each session. Stock solution lasts. Working solution does not.

 

[Michel Hardy-Vallée]

BTW, you don't need HCA for film. Wash proplery (15mins in running water, or multiple fill and dump), and you're set. The slight coloration of the film base will not matter when you are printing.

 

[justinphilip]

But how much water and powder?

 

[fschifano]

Are there no directions on the package? For best results, it pays to follow the directions.

 

[justinphilip]

Okay thanks. I am just not sure of how much water. On the packet it has three containers in a row. The first one has water pouring in and it says next to it 800ml/.21 Gallon. The second shows adding the powder and the third container has water pouring in it and next to it says 950ml/.25 gallon. But the instructions say this is to make a working solution of .25 Gallons. So I take it that it is just the whole packet and .25 gallons of water. But why does it say 800ml/.25 gallons?

 

[Monophoto]

But how much water and powder?

Justin -

When you mix from powders, it is always a good idea to mix all of the powder at once. It is possible for the components in a powdered chemical to separate as the package is handled, and the only way to assure that the final chemical contains the intended proportions of all components is to mix the entire package at once.

My copies of Kodak literature tell me that HCA powder is diluted in water to make a stock solution, and that the stock solution is supposed to last 3 months in a closed container. Then, you dilute one unit of stock solution in four units of water to make a working solution. IIRC, one package of the powder makes five quarts of stock - it should tell you on the package. One of the reasons I've never used Kodak HCA is that 5 quarts is an inconvenient volume to store.

There are other wash aids available on the market as liquid concentrates - OrbitWash, Heico PermaWash, Sprint Hypo Remover, etc. Liquid concentrates have the advantage that it is not necessary to mix the entire container at once, and my experience is that those liquid concentrates last significantly longer than the three months advertised by Kodak.

 

[Michel Hardy-Vallée]

Okay thanks. I am just not sure of how much water. On the packet it has three containers in a row. The first one has water pouring in and it says next to it 800ml/.21 Gallon. The second shows adding the powder and the third container has water pouring in it and next to it says 950ml/.25 gallon. But the instructions say this is to make a working solution of .25 Gallons. So I take it that it is just the whole packet and .25 gallons of water. But why does it say 800ml/.25 gallons?

It's easy: you need three buckets of water. In the first one you pour water, in the second one you add the powder, and in the third one you pour water.

You then divide 950mL by 0.25 Gal, which should give you the equivalent of three times 800mL in quarters of gallon. Do so by pouring the first bucket in the other two.

Then you mix all three buckets together and you dilute 1+4 for use. It's easy.

 

[jeroldharter]

I agree with the previous post. Get the liquid concentrates and mix just what you need. I use Heico Permawash and can remember 3 0z/ Gallon of working solution or about 46 ml/2000 ml working solution off the top of my head.

In other words, the standard 32 oz bottle will make about 11 gallons of working solution which lasts me for quite awhile.

I always find Kodak instructions frustrating.

 

[johnnywalker]

The package I have says for a working solution 454 grams of powder makes 19 litres. If you want a "stock" solution (recommended) add the 454 grams to 3.8 litres. To make the working solution from the stock solution, use one part stock to 4 parts water.

 

[Bruce Osgood]

Okay thanks. I am just not sure of how much water. On the packet it has three containers in a row. The first one has water pouring in and it says next to it 800ml/.21 Gallon. The second shows adding the powder and the third container has water pouring in it and next to it says 950ml/.25 gallon. But the instructions say this is to make a working solution of .25 Gallons. So I take it that it is just the whole packet and .25 gallons of water. But why does it say 800ml/.25 gallons?

Firstly, there arn't 3 buckets, there is only one bucket that requires three steps.

To one bucket add .21 gallon water
to that, add powder - stir it up real good.
Now add enough water to make a total.25 gallon (1 quart) Hypo Stock.

Use as you choose.

 

[justinphilip]

Thank you.

Why couldn't it have just said add .21 gallon water, and add the packet, then add .04 gallon water?

 

[Michel Hardy-Vallée]

Thank you.

Why couldn't it have just said add .21 gallon water, and add the packet, then add .04 gallon water?

Well, that's pretty much what the little comic strip says. Put some 800mL of water, stir in the packet, and top it up to 1L. Simple as that.

 

[Sirius Glass]

Okay thanks. I am just not sure of how much water. On the packet it has three containers in a row. The first one has water pouring in and it says next to it 800ml/.21 Gallon. The second shows adding the powder and the third container has water pouring in it and next to it says 950ml/.25 gallon. But the instructions say this is to make a working solution of .25 Gallons. So I take it that it is just the whole packet and .25 gallons of water. But why does it say 800ml/.25 gallons?

Should be: "So I take it that it is just the whole packet and .21 gallons of water. But why does it say 800ml/.21 gallons"

1) mix power with 800ml/.21 Gallon of water. That is your stock solution.
2) for film take the stock solution and mix it 4 water to 1 stock solution. Therefore if you want a quart take 32 ounces /5 = 6.4 ounces of stock and add it to 25.6 ounces of water [or just fill it up to make a quart].
3)for paper take the stock solution and mix it 7 waters to 1 stock solution. Therefore if you want a quart take 32 ounces /8 = 4 ounces of stock and add it to 28 ounces of water [or just fill it up to make a quart].

Clear as mud? PM me if you need further clarification. [pun intended]

Using HCA is a good way to conserve water.

Steve

 

[srs5694]

FWIW, I also found Kodak's "comic strip" instructions quite confusing when I first started out. I think they were trying to come up with something that'd be understandable to everybody worldwide, regardless of language. Unfortunately, the result isn't as clear as conventional instructions presented in the customer's native language would have been. Bruce's summary, above, is far clearer than Kodak's instructions, IMHO.

 

[brandonjscott]

The chemicals add volume, so you begin with 800ml of water, add the chemicals, then add enough water to bring the total to 950 ml. This does not mean you are going to add 150ml of water after you add the chemicals to the 800ml you may only be adding 127ml. The important thing is you wind up with 950ml of stock HCA inclusive of chemicals and water. You then dilute the stock to make the working solution prior to use. To make 1 litre of working solution combine 200ml of stock HCA with 800ml of water (1:4).

 

[bill spears]

HCA Dilution

Justin -

''When you mix from powders, it is always a good idea to mix all of the powder at once. It is possible for the components in a powdered chemical to separate as the package is handled, and the only way to assure that the final chemical contains the intended proportions of all components is to mix the entire package at once.

My copies of Kodak literature tell me that HCA powder is diluted in water to make a stock solution, and that the stock solution is supposed to last 3 months in a closed container. Then, you dilute one unit of stock solution in four units of water to make a working solution. IIRC, one package of the powder makes five quarts of stock - it should tell you on the package. One of the reasons I've never used Kodak HCA is that 5 quarts is an inconvenient volume to store.''



I've always found the large volume of stock solution a bit inconvenient too, especially if there are long periods between my printing sessions.
Someone correct me if I'm wrong but is the dilution of the working strength solution not too critical, as the purpose of HCA is just to 'weaken' or convert the fixer to a more soluble compound ? I've heard that seawater has a similar effect.
Recently I've actually taken to using about a teaspoon of powder straight from the packet and diluting it in around half a litre of water to use as my working solution. After soaking, FB prints get a final thorough wash in running water for about 30 mins.
I am a bit concerned now about the ingredients of the powder becoming separated in the packet as mentioned, although isn't HCA practically just sodium sulphate ?
Bill

 

[Changeling1]

Hey guys. I am new here. I just got my chemistry so I can start developing my own film. I am having a question about one thing though. I got Kodak Hypo Clearing Agent and I am not sure how to mix a working solution for this. Does anyone here use this? The instructions are a bit confusing to me. How much of what do I need to use to make a stock solution? Or is there a way that I can go straight to making a working solution? Sorry if this is a dumb question. Thanks!

Not a dumb question but I would recommend Perma-Wash over the other brands. Easy to mix, economical and long-lasting.

Dead Link Removed

 

[dancqu]

Why couldn't it have just said add .21 gallon water,
and add the packet, then add .04 gallon water?

Add water to make. Remember that. Add water to make.
As has been mentioned chemicals added to water will
increase the volume. Add water to make 1 liter is
the instruction which should have been on the
package. One liter, a convenient amount.
A lot of one liter bottles about.

For longer solution life I'd suggest 4, 1/4 liter bottles.
An exact final volume is not necessary. Hypo Clearing
Agent will oxidize on exposure to air. It is not needed
for film. Dan

 

[Bruce Osgood]

Thank you.

Why couldn't it have just said add .21 gallon water, and add the packet, then add .04 gallon water?

Because they're KODAK.
There are 3 ways to do something: There's the right way, the wrong way and the Kodak way.

 

[john_s]

If the size of stock solution is inconvenient, you can make a more concentrated stock. I have made it to about x2 strength (i.s. in half the amount of water), although it takes a bit of dissolving. Then dilute it 1+9 instead of 1+4. Precision is not needed anyway.

 

[Sirius Glass]

Because they're KODAK.
There are 3 ways to do something: There's the right way, the wrong way and the Kodak way.

Here we go with the usual anti Kodak BS.
1) Most of the world uses the metric system. Get over it.
2) At 800 ml, it can be stored in a collapsable bottle to keep the air out. When some of the stock solution is used; collapse the bottle some more. Not exactly rocket science, eh?
3) If all of it is diluted 4:1, it makes a gallon, not a hard container to find.

To recap:There are 3 ways to do something: There's the right way, the wrong way and Bruce's way.

Steve

 

[justinphilip]

Thanks for the clarifications. It was just the last step that confused me. All is says if 950ml. I wasn't sure it I was to add another 950ml or add water to make 950ml total. But I understand and got it. I was reading the instructions for the Kodak Rapid Fixer and the instructions are the same way except it actually says "Add water to bring solution to this volume." I am just not used to instructions being this way. Thanks again.

 

[Sirius Glass]

The instructions are confusing at best.

Steve