Hypo Check Expired

I've been using some Edwal Hypo Check that is about a hundred years old. When a drop of it in my paper or film fixer turns milky I dump and remix and refix if neccesary.

Today I check my film fix before doing some processing. Dang! the EHC turns milky. But I don't think that batch of film fixer has been used all that much so I grab a piece of clipped leader and dip it in the bottle. It clears up in less than a minute.

Is anyone aware of an expiration to Hypo Check or should I just cease to trust it altogether?

When your Hypo Check Bounces

If you've had yours for 100 years, sounds like 99 might be the limit.

The bottle I'm using is probably 10 years old, and still works as expected. I've never heard of an expiration time, but there are a couple of things out there I haven't heard about.

Same here. 20 years old.

Are you guys sure that it is properly indicating that your fixer is exhausted?
I've been using this stuff for the last two years, dumping my fixer on it's say-so. Now I'm thinking that I have dumped a $h*tload of perfectly good fixer down the drain.

Flotsam said:

Are you guys sure that it is properly indicating that your fixer is exhausted?

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I think so. It dissipates when I think it should based on recollection of prints or rolls/sheets processed, and stays cloudy about the same time I think I've reached the limit.

I've been using this stuff for the last two years, dumping my fixer on it's say-so. Now I'm thinking that I have dumped a $h*tload of perfectly good fixer down the drain.

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That may be true. In fact, the six-legged frog in my back yard may prove it.

Could it be that hypo check is an evil plot? A massive conspiracy to boost the sales of fixer?

Buckle your seatbelts, people. We're through the looking glass here! If APUG mysteriously shuts down we'll have to communicate by exchanging latent images.

hi neil

i use sprint fixer and i know when the edwal's says my fixer is exhausted it is about 1/2way exhausted. the hypocheck that is in the bottle is really strong "brine" ( salt water ) and the bottle says to get about 1oz of your fixer and put a few drops in - stir it up ...

i pretty much have lost my faith in the stuff, and before i begin printing i just get a 1"square piece of film and ( with the lights on ) drop it into the fixer. when it clears i double the time and that is about how long i fix for.
when you get the film to clear 5+ mins, you might want to consider making fresh fixer

i usually do 2 fixer baths and i remove from the first bath at the time my "test" film clears, and put it into my second bath to do the "clean-up-fix".

ps. edwal's hypo check was originally formulated to be used with edwal's fixer so when it says your fix is spent, it probably isn't really spent ...

I haven´t used that particular fix test, but it sounds very much like the standard potassium iodide test recommended in classic photo literature - mix PI with water, put an amount to another amount of fixer and watch it. Shake the thing, if the milky cloud doesn´t clear up then, the fix is spent.

So it works with any fix, not just the one mady by Edwal.

That test has certain problems with film fix - film emulsions (actually suspensions, not emulsions) contain a high amount of silver iodide which triggers the test much too late.

Better yet to use a two bath fix and thus you´ll end up with a much higher useful life of your solutions. Let me throw in a table made by Mr. Gudzinowicz in rec.photo.darkroom, I hope the format isn´t spoiled to much:

One-bath fixation: Commercial Archival

Paper:

Max. Ag conc.: 0.3 g/l 0.05 g/l
Max. sheets/gal: 30 8x10 5 8x10
Non-image Ag in paper: 0.005 mg/in^2 0

Two bath fixation: Commercial Archival

Paper:

Bath 1:Max. Ag conc.: 2 g/l 0.8 g/l
Max. sheets/gal: 200 8x10 70 8x10

Bath 2:
Max. Ag conc.: 0.3 g/l 0.05 g/l
after 200 after 70

Non-image Ag in paper: 0.005 mg/in^2 0

Nach
Michael Gudzinowicz

I you care I may dig out a table a friend of mine made - he made a titration test with that PI solution and measured the according silver content.

John, I think that I will have to use that method from now on.

Roman, The format of the table is a bit off but it's easy to read the results.
Due to space constraints and relatively low production, I will probably stick with a single bath but since you can't toss a piece of paper in the fix and watch it clear, the only thing to go by is capacity and keeping track of usage.
Thanks for the info.

Neal,

I tried to correct it, but the browser wouldn´t accept tabs in that table. Grmpf.

One odd thing is - you can go in the shop and buy that fix tester... but something like that isn´t available in Germany, so we slightly advanced users go to the pharmacy (or chemistry shop) and buy 1g of Potassium Iodide for 1,50EUR incl. weighting it, mix it with 20ml of water. I prefer it that way. ;->

There isn´t much that in it that might go bad - mine is 4 years old, something is growing in there (I used an empty glass of Pesto Genovese for that and it probably wasn´t that clean then), but I don´t care since the iodide isn´t compromised by that.

You can actually throw in a piece of paper - fix it, wash it, put it in the developer. If there is the slightest tone of fog or black, your fixer is bad.

All in all my credo is "fixer is cheap, film, paper, images aren´t". So I take no risks.

So you are saying, 1 gram of PI to 20ml water? Thanks, I may try that.

With RC paper, that fix, wash, develop test could probably be done without fear of contaminating your developer. It's a bit of a hassle though.

Neal,

there are many varying recipes on it which difer in quantity of PI, but they function all the same - but vary in application, you have to adapt the amount of PI solution vs. the amount of fix...

One more example from Kodak, which is good for a ten times lifetime stock solution. ;-)

http://wwwtw.kodak.com/cluster/global/en/professional/support/techPubs/o3/O3wp4.jhtml#1308927

As promised, I digged out the report from Franz on the test - i was curious myself. Franz is a chemist, he repeated the titration five times over.

See (in german): http://phototec.de/phorum_neu/read.php?f=3&i=48812&t=48812

In short and english: 500ml of 1+7 Tetenal Superfix (ordinary rapid fix), used with 5 Filmes, clearing time was 210 sec. Titration showed a silver content of 3,4g/l - WAY too much, while the clearing time indicated "good for at least another film".

Then he took a fresh fixing bath of same scheme and added silver nitrate. His results:

- PI, a 10% Solution
- 1ml of that on 10ml Fix
- prescipation at 21° ambient temp was stabile when the silver content hit the 2,8g/l mark.

SNIP:

rjr said:

So it works with any fix, not just the one mady by Edwal.

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hey roman -

the brine test is great for seeing silver saturation ... but it isn't very accurate ( as you have suggested ) .... in many cases, like with high capacity fixers, "spent", it just isn't .... i kind of wish everything was like that <gggg>


SNIP:

Flotsam said:

John, I think that I will have to use that method from now on. Thanks for the info.

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sure thing - i'm glad i could help

- john