Kodak Residual Hypo test kit

[FrankB]

Hi all,

Having read a few posts and a couple of bits in books about how to set up an archival print processing system, I thought I'd better verify how close I was getting to the real McCoy.

I contacted Silverprint in the UK to obtain a Kodak Hypo Estimator and some Hypo Test Solution. They went away and talked amongst themselves for a while. Then they came back and informed me that these products were no longer available... ...to them from Kodak.

"Oh dear", I said (or words to that effect).

The questions I would like to pose to the esteemed and knowledgeable persons in this forum (and anyone else that happens to be passing! :-) ) are:

1) Have the products been discontinued by Kodak, or are Silverprint mistaken?
2) How else can I test for residual hypo levels?

Thanks in advance,

Frank

...Belt, braces and a piece of string... ...only without the belt and braces.

[Jorge Oliveira]

I donno how to test - but what about an HCA (hypo clearing agent) bath?

Easy: 1 canister of 35mm film filled with sodium sulphite in 2 liters water. Mix tlii solved.

After fixing, do a quick wash, immerse prints in this solution for some 2 min. aggitating and then wash normally.

Jorge O

[Jeremy]

I'm not sure of the cost to ship it, but photographer's formulary sells a residual hypo test. Here's a link:

http://www.photoformulary.com/Deskto...ion=0&langId=0

If someone here is doing some shopping at the formulary you could have them buy you a bottle and then ship it, might be cheaper that way. Just trying to help out! Also, you might try Robert White, they seem to be very helpful chaps and may be able to sort things out for you and come up with some residual hypo tester.

[Bruce Osgood]

I don't know about Kodak products availabiliity but to check for residual silver on a print you can use a simple solution of Kodak Rapid Selenium Toner and water.

Place a couple of drops of KRST 1:9 on the emulsion in a clear area. Let it sit for two to three minutes and squeegee off. There should be no stain. Residual silver will be apparent as a fairly dark yellow or brownish stain.

You can do this after fixing or after washing, but before toning.

[glbeas]

Darkroom Cookbook has the recipe for the solution. The components should be easily available.

[FrankB]

I don't know about Kodak products availabiliity but to check for residual silver on a print you can use a simple solution of Kodak Rapid Selenium Toner and water.

Place a couple of drops of KRST 1:9 on the emulsion in a clear area. Let it sit for two to three minutes and squeegee off. There should be no stain. Residual silver will be apparent as a fairly dark yellow or brownish stain.

You can do this after fixing or after washing, but before toning.

Hmmm...

Most of the stuff I'm actually bothered about being archival I'll be selenium toning anyway (albeit with MACO at about 1:20 to get increased dmax without too much of a colour shift). If a stain caused by insufficient washing will show up that quickly and clearly I'm wondering whether I'm actually fussing about nothing here... What do you think?

Also, would the toner in this case need to be fresh or could it be stored for a while as a test kit?

Thanks in advance,

Frank

...A good barber and a good tailor can make a man look young, but you can't fool a flight of stairs.

[Bruce Osgood]

Snip
If a stain caused by insufficient washing will show up that quickly and clearly I'm wondering whether I'm actually fussing about nothing here... What do you think?

Also, would the toner in this case need to be fresh or could it be stored for a while as a test kit?

Thanks in advance,

Frank

end snip

No, I don't think you are fussing about nothing. After all, the only true test of a prints archival abilities is to have a look at it again in 100 years. If its' turned yellow or fadded you'll need to redo it. Not a responsibility I would like to take on.

You can store your test solution, just as you would store your working solution. BTW, it is believed that a trace amount of hypo remaining in the emulsion after wasing adds to the archival permenance of a print where complete removal of all hypo lends to its' deteration.

[DKT]

It was called an HT-2 test kit (Hypo Test Kit) They had a corresponding ruler-the hypo estimator-- that has a protective sleeve as well. There are stain densities on this ruler that correspond to test target stains listed in the Kodak B&W Dataguides and other publications & tech sheets. Different papers are broken down to different densities..you lay this ruler alongside the paper base you're checking & evaluate the stain visually. This test is not 100% positive. It's not as accurate as a test that would use a densitometer or other type of lab equipment. When it comes to processing of microfilm for example, in archives they use different tests to check for residual fixer, and these are usually performed at set periods of time, like weekly or at intervals through certain projects. The tests are done to comply with standards in use in archives & records storage ... there's also a test for residual silver that would check the activity of the fixer through a stain on the paper.

It could take years & years for any problems to pop up from incomplete washing. It might not really be a factor depending on how long you intend to use the prints, but whatever is left behind, can cause problems if the temps & humidity of storage get to a point where they can trigger this deterioration--if you stored them in a place devoid of any moisture or heat , they might fare better....

KT

[Donald Miller]

BTW, it is believed that a trace amount of hypo remaining in the emulsion after wasing adds to the archival permenance of a print where complete removal of all hypo lends to its' deteration.

Interesting comment and one that I have not heard before. What and who is the basis of this statement? It would be interesting to read documented research on this. I would appreciate anything that you can provide on this matter. Thanks and regards, Donald Miller

[Bruce Osgood]

BTW, it is believed that a trace amount of hypo remaining in the emulsion after wasing adds to the archival permenance of a print where complete removal of all hypo lends to its' deteration.

Interesting comment and one that I have not heard before. What and who is the basis of this statement? It would be interesting to read documented research on this. I would appreciate anything that you can provide on this matter. Thanks and regards, Donald Miller

I came by this from the Pure-Silver list, Richard Knoppow. Richard is a walking encyclopedia of all things wet &/or measurable.