Mixing Kodak HCA

[scootermm]

Ive done a pretty exhaustive internet/forum search on here and a few other forums. I ordered the chemicals from chemistrystore.com to mix it up myself... but dont know the quantities. I usually purchase the dry packs of Kodak HCA at a local photo store here in Austin, but alas they have gone the way of the dodo and no longer carry ANY darkroom chems or supplies. So I thought Id remedy it and premix the dry chems myself.

can anyone assist in telling me what ratios to mix up the chemicals?

thanks in advance.

 

[Lee L]

From Anchell's Darkroom Cookbook

water 750 ml
sodium sulfite 200 grams
*sodium bisulfite 50 grams
water to 1 liter

To make a working strength bath, dilute 1 part washing aid to 9 parts water.

* The sodium bisulfite lowers the pH in order to prevent softening of the emulsion of film. If used with paper, the bisulfite may be left out in order to improve the paper's gloss.


Lee

 

[Brickbird]

HCA

Ive done a pretty exhaustive internet/forum search on here and a few other forums. I ordered the chemicals from chemistrystore.com to mix it up myself... but dont know the quantities. I usually purchase the dry packs of Kodak HCA at a local photo store here in Austin, but alas they have gone the way of the dodo and no longer carry ANY darkroom chems or supplies. So I thought Id remedy it and premix the dry chems myself.

can anyone assist in telling me what ratios to mix up the chemicals?

thanks in advance.

Matt,
What chems did you buy? I have the formula for HE-1 from Kodak and will forward it to you. It states that this formula reduces hypo all the way to sodium sulfate which is harmless to the silver image and soluble in the final washing. They are talking about prints in this case but it will work just the same.
Tav

 

[scootermm]

The chems I purchased were/are 12lbs of Sodium sulfite and 2 lbs of sodium metabisulfite. (along with some citric acid, oxalic acid, and EDTA - but those are for other uses)

Forgot to mention the reason I bought the chems was because I have had great experience using Kodak HCA as a clearing agent for pd/pt prints. I usually bought about 4 packets of it and poured all the packets into a container and would create my three clearing baths by spooning 4 heaping spoonfuls into a tray of 4Ls of hot water along with a few spoonfuls of EDTA, works quite well to clear all the papers I have tried out (Fabriano Artistico, Rives BFK, Cranes Cover/platinotype, Arches Platine, and a few others)

From Lee L's comment I believe I will premix 2000 grams of dry Sodium Sulfite with 500 grams of dry Sodium Metabisulfite and then when I create each clearing bath Ill be able to just spoon out the heaping tablespoons into the trays.

sounds like that may be the simplest manner to do it.

 

[photomc]

Matt, not the formula for HCA..but to clear my pd/pt prints I use a teaspoon of sodium sulfite and the same of EDTA per liter of warm water. Use it just as you describe above...have not had any issues. HCA has some other items in it, but the sulfite is the primary - mixed with the EDTA I think you should be fine. BTW have a copy of Anchell's cookbook, so give a shout if you need me to find it and look something up.

 

[scootermm]

thanks mike and thanks to everyone else for the info.

 

[Brickbird]

HCA

The chems I purchased were/are 12lbs of Sodium sulfite and 2 lbs of sodium metabisulfite. (along with some citric acid, oxalic acid, and EDTA - but those are for other uses)

Forgot to mention the reason I bought the chems was because I have had great experience using Kodak HCA as a clearing agent for pd/pt prints. I usually bought about 4 packets of it and poured all the packets into a container and would create my three clearing baths by spooning 4 heaping spoonfuls into a tray of 4Ls of hot water along with a few spoonfuls of EDTA, works quite well to clear all the papers I have tried out (Fabriano Artistico, Rives BFK, Cranes Cover/platinotype, Arches Platine, and a few others)

From Lee L's comment I believe I will premix 2000 grams of dry Sodium Sulfite with 500 grams of dry Sodium Metabisulfite and then when I create each clearing bath Ill be able to just spoon out the heaping tablespoons into the trays.

sounds like that may be the simplest manner to do it.

HE-1 is as follows:
Water........500ml
Hydrogen Peroxide......125ml (3% solution)
Ammonia Solution.......100ml(1 part concentrated ammonia(28%) to 9 parts water
Add water to make 1 liter.

This comes from the Photo Lab Index-1976 Edition. It states that in the past many different formulas failed to oxidize hypo to harmless sodium sulfate. It states that HE-1 does just that completely. Good luck.

Tav

 

[David Brown]

sodium sulfite 200 grams

Anybody know how much that is in teaspoons or tablespoons?

(for the scaleless ...)

 

[Brickbird]

Measures

Anybody know how much that is in teaspoons or tablespoons?

(for the scaleless ...)

A teaspoon is 5ml. A tablespoon is 15ml. Hope that helps.

Tav

 

[David Brown]

..

 

[Tom Hoskinson]

HE-1 is not recommended by Haist

HE-1 is as follows:
Water........500ml
Hydrogen Peroxide......125ml (3% solution)
Ammonia Solution.......100ml(1 part concentrated ammonia(28%) to 9 parts water
Add water to make 1 liter.

This comes from the Photo Lab Index-1976 Edition. It states that in the past many different formulas failed to oxidize hypo to harmless sodium sulfate. It states that HE-1 does just that completely. Good luck.

Tav

HE-1 (and complete hypo removal) is not recommended by Grant Haist in his book: Modern Photographic Processing.

Best to use sodium sulfite based HCA, instead.

 

[Lee L]

Anybody know how much that is in teaspoons or tablespoons?

(for the scaleless ...)

Anchell's book says about 7.9 grams per teaspoon for sodium sulfite anhydrous.
For sodium bisulfite about 5.5 grams per teaspoon.

How do you practice your scales?

Lee

We shall come rejoicing, bringing in the sheets.

 

[clay]

The thing about clearing is that you need enough and no more. And every paper is different. For instance Rives BFK is a beautiful paper, but a real bite in the butt to clear. In contrast, Cranes clears very easily. The point being that you need to experiment a little bit and figure out what concentration and time you need to adequately clear any given paper. I used to mix up a home brew hypoclear as follows:
1 teaspoon sodium bisulfite in a liter of warm water and stir until dissolved, then
1 tbsp of sodium sulfite
and then
1 tbsp of EDTA.

This would generally clear COT320 with three five minute baths.

It is advisable when you are first using a new paper to mask the border and check your clearing by holding your paper up to a light and seeing if you can detect residual ferric oxalate. There is also a chemical test that, if I remember correctly, involves adding a little drop of a potassium ferricyanide solution to a supposedly cleared area. You'll have to google that one. I like the visual check.

If it isn't clearing, check the pH of your clearing baths. If they are above 7, you are just pissing into the wind. Some stubborn papers may require a first bath of phosphoric acid or even dilute (1-2%)hydrochloric acid. Just be aware that if you throw a piece of paper that has spent five minutes in a hydrochloric acid bath straight into a tray containing sodium sulfite, you may think you have a rotten egg somewhere in your darkroom. So it is a good idea to briefly rinse the paper after the acid bath if you are using a strong acid as a clearing agent. It is not an exact science, as you can see from this rambling post.....

 

[scootermm]

fully agree clay.
Ive learned, from many foul ups, that my clearing baths vary for different papers. for instance, in my experience, FA EW clear very well in 1L water, 2 tbsp HCA, 1 tbsp of EDTA. While Cranes Cover will clear fairly easily in 1L water and just the HCA (2 tbsp). The one common denominator Ive noticed is that I use HCA in some ratio in all my clearing baths, regardless of paper. Hence my desire to find a nice "home brew" method of mixing up HCA to similar ratios as the packaged Kodak version.
Instead of mxing my dry chems of Sodium Sulfite and Sodium Metabisulfite I think I may just test out the tablespooning method as you mentioned clay. Thinking Ill give a shot tonite with: 1L hot water, 2 tbsp sodium sulfite, 1 tbsp sodium metabisulfite a shot and see how it works for me.
Seems like this would be an easier way to just spoon out the dry chems in the trays and not have to deal with adequately mixing the dry powders together.

thanks for the info and the measurements.

 

[David Brown]

How do you practice your scales?

Lee

Alas, Lee, this is why my piano playing never got that good. Turned me into one heck of a drummer in the day, though.

"I got rhythm, I got music ..."

 

[Jeremy]

Matt, I actually use a citric acid bath first followed by 2 clearing baths clay described above and haven't had a problem with any paper i've used.

 

[BradS]

Anybody know how much that is in teaspoons or tablespoons?

(for the scaleless ...)

David,
I'm kinda working from memory here but, if you can find Patrick Gainer's teaspoon receipe fro Kodak D-23, you can verify this...

for Sodium Sulfite, I believe 4 Tablespoons is about 100grams. It might be 4 Tablespoons plus one teaspoon...

so, 200g of Sodium Sulfite would be something like 8 or 9 Tablespoons

 

[Donsta]

I use Heico Permaclear for clearing Pt/Pd and it works very well, even on combinations which are tradionally "difficult" to clear - I use 3 5 minute baths of working solution (3oz to a gallon). You can buy this stuff from Calumet shipped to your door for under $50 and that's enough for about 50 gallons of working solution. It really doesn't add any cost to your process.