Hypo - diy?

skljocnulbumte · Jun 9, 2017

Hello!

I have a plan to diy Hypo in accordance with Unblinking eye's formulat for 1L
http://unblinkingeye.com/Articles/De.../formulas.html

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.

My qustion is: How many films or fb papers I could soak in 1:9 working solution?

Thanks

dwross · Jun 9, 2017

To clarify: are you interested in making fix (aka "hypo") or hypo clearing agent? Two very different formulas for opposite tasks. May I recommend The Darkroom Cookbook, any edition, for the information you are looking for.

Gerald C Koch · Jun 9, 2017

dwross said:
To clarify: are you interested in making fix (aka "hypo") or hypo clearing agent? Two very different formulas for opposite tasks. May I recommend The Darkroom Cookbook, any edition, for the information you are looking for.

+1

skljocnulbumte · Jun 9, 2017

Hello!
I'm interested for making hypo clearing agent .

john_s · Jun 9, 2017

skljocnulbumte said:
Hello!
I'm interested for making hypo clearing agent .

The formula is fine. But its capacity is limited by exposure to air rather than the amount of material put through it. I make it as I go in small quantities, and precise measurements are not critical.

darkroommike · Jun 9, 2017

You should use the diluted stock solution at the rate of 20 8x10's per quart/liter or you can make it as a one shot formula (just 20 grams of sodium sulfite per liter), no need then to dilute and no need for sodium bisulfite (the bisulfite acts as a buffer to extend the keeping properties of the stock. Then use the hypo clearing agent at the same rate as the hypo (sodium thiosulfate aka hyposulfite of soda). About 20 8x10's per quart/liter of working solution.

Ian Grant · Jun 10, 2017

darkroommike said:
You should use the diluted stock solution at the rate of 20 8x10's per quart/liter or you can make it as a one shot formula (just 20 grams of sodium sulfite per liter), no need then to dilute and no need for sodium bisulfite (the bisulfite acts as a buffer to extend the keeping properties of the stock. Then use the hypo clearing agent at the same rate as the hypo (sodium thiosulfate aka hyposulfite of soda). About 20 8x10's per quart/liter of working solution.

I agree with Mike, I just make up a fresh bath each printing session an just use Sodium Sulphite there's no benefits from adding Sodium Metabisulphite.

Ian

Pat Erson · Jun 10, 2017

Ian, is sodium hexametaphosphate necessary or superfluous?

Thx!

Ian Grant · Jun 10, 2017

Pat Erson said:
Ian, is sodium hexametaphosphate necessary or superfluous?

Thx!

Yes and no

It really depends on your wash water quality, it's there to soften hard water. The water here is quite hard I have to use a water oftener (filter jug) for my kettle and I get calcium build up in our shower. I swab the face and rear of my prints after washing to prevent drying marks. Ideally the final rinse would be in filtered water but I get no problems on films or prints. It seem rather illogical having a water softening agent in the Hypo clear when the wash afterwards is in hard water.

I've used plain Sodium Sulphite condition for 30 years now, I can't see any point on adding anything else - that was the conclusion of both Ilford and Kodak (Harrow) research. If you're making a concentrated stock solution then you may want to add metabisulphite and hexametaphosphate.

Ian

Pat Erson · Jun 10, 2017

Thx and no thx Ian! ;-)

~andi · Jun 10, 2017

I need to add SHMP. Using distilled water is another option.

Rudeofus · Jun 10, 2017

The Sodium Metabisulfite from the formula brings pH of hypo clearing agent down to nearly neutral, and this gives you three advantages:

It's safer in terms of handling and splashes
If you have carryover of Ammonium ions, a neutral HCA won't liberate smelly Ammonia
It's much less likely that you need a Calcium/Magnesium sequestering agent like Sodium Hexametaphosphate or EDTA or distilled water. All of these alternatives are more expensive.

Ian Grant · Jun 10, 2017

Actually the alkali pH of plain Sodium Sulphite is more beneficial in shortening wash times and removing residual silver/thiosulphate complexes, that's why Agfa suggested using Sodium Carbonate as a wash aid. In 30 years I've never detected any ammonia smell in the plain Sulphite hypo clear or when I've used Sodium Carbonate but my prints have had at least 10 mins wash before I use it.

In terms of safety Sodium Sulphite is only pH9 for a saturated solution (27%), a 2% solution isn't a hazard, even at 10% it's not listed on MSDS sheets for working strength developers.. Metabisulphite is used in commercial concentrated HCA solutions to help prevent the Sulphite oxidising and forming Sulphate.

Ian

Rudeofus · Jun 11, 2017

Ian Grant said:
Metabisulphite is used in commercial concentrated HCA solutions to help prevent the Sulphite oxidising and forming Sulphate.

How in the world would that work ?

Ian Grant · Jun 12, 2017

The free SO2 is a very powerful anti-oxidant, it's added to powder developers (Part A) to stop the developing agents oxidising, but when mixed in solution it,s neuratlised and the Metabisulphite becomes Sulphite.

A Sulphite solution breaks down when stored, particularly in a part filled bottle so the Metabisulphite just keeps it stable.

Ian

nmp · Jun 12, 2017

Ian Grant said:
A Sulphite solution breaks down when stored, particularly in a part filled bottle so the Metabisulphite just keeps it stable.

Ian

Hi, Ian:

Can you please tell me how long before a partially used plain sulphite based HCA before the need to chuck it out. I make a gallon at a time. Sometimes I might have a partial for weeks or months. Never thought it would go bad.

Thanks.

:Niranjan.

Ian Grant · Jun 12, 2017

I use plain Sulphite as a one off, using just what I need so I don't store and reuse. Once used and dilute you run a far higher risk of it decomposing to Sulphate which will negate any benefits.

Ian

nmp · Jun 12, 2017

Ian Grant said:
I use plain Sulphite as a one off, using just what I need so I don't store and reuse. Once used and dilute you run a far higher risk of it decomposing to Sulphate which will negate any benefits.

Ian

Thanks for the info. Darn, one more thing to worry about....

Doremus Scudder · Jun 12, 2017

nmp said:
Thanks for the info. Darn, one more thing to worry about....

No worries, it's easy: 1 Tablespoon of sodium sulfite and a generous pinch of sodium (meta)bisulfite per liter and you're good to go. The proportions are not critical. Capacity is similar to Kodak HCA.

Best,

Doremus

RalphLambrecht · Jun 12, 2017

dwross said:
To clarify: are you interested in making fix (aka "hypo") or hypo clearing agent? Two very different formulas for opposite tasks. May I recommend The Darkroom Cookbook, any edition, for the information you are looking for.

I made only positive experiences with the formulae in that book

Rudeofus · Jun 12, 2017

Ian Grant said:
A Sulphite solution breaks down when stored, particularly in a part filled bottle so the Metabisulphite just keeps it stable.

I have the impression you confused HCA with fixer here. I understand that you can protect Thiosulfate with Sulfite or Bisulfite, but you definitely can't protect Sulfite with Metabisulfite.

nmp · Jun 12, 2017

RalphLambrecht said:
I made only positive experiences with the formulae in that book

Did you know if you click on your link (darkroommagic) it takes you to one of those spam sites with security warning. It locked my browser and I had to get the task manager to bail.

RalphLambrecht · Jun 12, 2017

skljocnulbumte said:
Hello!
I'm interested for making hypo clearing agent .

Your formula is fine and it is one of the easiest processing chemicals to make;just replace after each session.

M Carter · Jun 13, 2017

I buy sodium sulfite by the pound online and make HCA with a good shake of that and some salt. Been doing that forever, my understanding has always been NACL is a decent wash boost. I don't know if that's overkill, but salt is like fifty cents a pound... I do an initial mix with hot water to dissolve the salt and sulfite, then cold water to make, well, however much I need, depending on if I'm processing film or prints. I test everything with RHT and it's all good. (And yeah, I HCA all my film - I'm not a run-around and grab shots guy, my negs usually take some work and effort, seems like cheap insurance - insanely cheap. And I test for fixing as well, with selenium, and do an RHT test as well).

~andi · Jun 13, 2017

Occams Razor. If all those formulas work, I'd go with the most simple one. Sodiumsulfite or Soda with ordinary tap water works fine according to my testing. Just make it fresh every session. If you get calcium deposits on your prints add a pinch of SHMP (we have very hard water so I use the 1/8th teespoon measuring spoon = about 1-2g per liter). Cost is really negligible with those amounts/hobby use. 1kg of SHMP is about 5 Euros or so (if you buy it in 1kg packs) und will last you 1000 liters of working solution. what do you need for one session? I make up 2 liters per session, that's 500 sessions for 5 Euros and you don't need another chemical.

Andi

Hypo - diy?

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