Rudeofus Concentrates and Working Solution for E-6 Prebleach Bath Based on Kodak's US5948604A

[Rudeofus]

Rudeofus submitted a new resource:

Rudeofus Concentrates and Working Solution for E-6 Prebleach Bath Based on Kodak's US5948604A - E-6 prebleach formula derived from patent US5948604A

Kodak provided a "teaching patent", i.e. a publication for preservation of knowledge, for their 5 liter E-6 home processing kit. The original patent text can be seen here. While anyone with access to these formulas and ingredients could start mixing and using, this article tries to make these formulas more accessible to amateurs. Please note, that all liquid ingredients except for dilute aqueous solutions and water are given in...

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[ChrisGalway]

Dear Rudeofus, Are you planning to provide similar details for the remaining E6 baths (bleach, fix and rinsing)? Chris

 

[Rudeofus]

Dear Rudeofus, Are you planning to provide similar details for the remaining E6 baths (bleach, fix and rinsing)? Chris

The official formula for bleach provided by Kodak is of little use to us, since it relies on HBr (Hydrobromic Acid) solution. I do plan on posting my own formulas for bleach and fixer at some point. Regarding final rinse: Ron Mowrey (aka PhotoEngineer) posted a decent final rinse formula.

 

[lantau]

The official formula for bleach provided by Kodak is of little use to us, since it relies on HBr (Hydrobromic Acid) solution. I do plan on posting my own formulas for bleach and fixer at some point. Regarding final rinse: Ron Mowrey (aka PhotoEngineer) posted a decent final rinse formula.

Conc. HBr is a stronger acid by pKa, but not really more difficult to handle than conc. HCl. Obviously you need to be able to do that safely. But I don't know what steps in particular are part of that Kodak recipe.

There are no particularly onerous restrictions on the purchase of HBr solution. In Europe, at least. After all you can buy HCl solution as well.

A copy of your ID will be needed for proof of age and that is pretty much it. I can see it at a German dealer I have used a couple of times (S3) and I can see it at a Dutch online shop which I am considering to try out soon. Apparently you can buy up to 100g of KMnO4 as a private individual.

 

[Rudeofus]

Conc. HBr is a stronger acid by pKa, but not really more difficult to handle than conc. HCl. Obviously you need to be able to do that safely. But I don't know what steps in particular are part of that Kodak recipe.

There are no particularly onerous restrictions on the purchase of HBr solution. In Europe, at least. After all you can buy HCl solution as well.

A copy of your ID will be needed for proof of age and that is pretty much it. I can see it at a German dealer I have used a couple of times (S3) and I can see it at a Dutch online shop which I am considering to try out soon. Apparently you can buy up to 100g of KMnO4 as a private individual.

Interesting point, did not expect to buy Hydrobromic Acid with so little hassle. As soon as you get stuff shipped, it becomes more of a hassle, if the compound is an acid/alkali, and yet more hassle, if it's a liquid.

Either way: the formula is in the patent, and the ingredients as listed in that patent will provide chemistry for 1/0.31 = 3 .23 liters of bleach.

For everyone else, who doesn't want to deal with HBr, there are a few simple ways to make bleach, which I have no published as a separate article.

 

[Rudeofus]

Regarding fixer (not sure yet, whether that's worth an article on its own): any neutral rapid fixer will work. Remember, that E-6 creates a high silver load (3*n emulsion layers vs. 1*n layers in B&W film), most E-6 emulsions use highly optimized flat crystals (re: fixing of TMAX films), so it has to be a rapid fixer. Don't use my quick fixer formula (or anything else based on Sodium Thiosulfate) unless you want to use it single shot.

There are ready made fixers for C-41 and E-6 process, and these are typically the cheapest and most suitable fixer concentrates you can find. There are also neutral rapid fixers sold for B&W processing (frequently under the title "odorless"). If the labeling on B&W rapid fixer concentrates won't tell, its MSDS tells you working solution pH. Anything between 6 and 7 will be fine. These ready made fixer concentrates are typically cheaper than any form of Ammonium Thiosulfate you can buy.

If you have access to even cheaper Ammonium Thiosulfate, you can mix Ryuji Suzuki's neutral rapid fixer formula, it's cheap&easy and perfect for color processing. Ron Mowrey's Superfix 1 is also an excellent starting point.

If you want to make a violent thug regardless of cost, try the following formula:

• 600ml tap water
• 200ml Ammonium Thiosulfate
• 50g Ammonium Thiocyanate
• 10 g Sodium Metabisulfite
• 2g DTOD
• Add Ammonia until pH reaches 6.5, then add water to make 1000ml.

 

[MattKing]

If you want to make a violent thug regardless of cost,

@Rudeofus - is "violent thug", perhaps, an example of auto-correct run amok?
If you need help editing it, just ask!

 

[Rudeofus]

@Rudeofus - is "violent thug", perhaps, an example of auto-correct run amok?
If you need help editing it, just ask!

This fixer formula is hideously expensive, but it clears dry Tri-X in less than 30 seconds, and dry Delta 3200 in less than 15 seconds.

Ron warned us, that high levels of thiocyanate can induce reticulation, so this fixer does have some traits of a violent thug IMHO. However, it's always been nothing but sweet&kind&gentle to my film rolls, so it's still in my formula collection.