Sunday, November 21, 2010

Kallitype Part 2 - Chemicals

I'm pretty sure my landlord thinks I'm cooking meth. My apartment is littered with chemical bottles of varying shapes, sizes and suspicious nature, and central Florida is the meth capital of the southeast. I've had to explain on more than one occasion that all this stuff is photo-related. And besides, I have all my teeth. (A very strong defense against being labeled a tweaker/Florida native).

These are the least threatening containers. They have fancy labels. Very professional looking. There are others smaller brown glass bottles that have a piece of masking tape on them with notes scrawled in Sharpie. Those make people nervous.

I've said before that I'm basically using Sandy King's recipe posted at Alternative with a few modifications.


Chemicals appearing in my collection:

- 1kg  Sodium Citrate powder
- 500g  Sodium Thiosulfate crystals
- 500g Citric Acid
- 500g Sodium Sulfite
- 100g Sodium Carbonate
- 50g Ferric Oxalate powder
- 30g Potassium Dichromate crystals
- 10g Silver Nitrate
- 10mL Gold Chloride

There's actually an easier way to accumulate the chemicals needed for doing Kallitypes. Photographer's Formulary sells a prepackaged kit that will make about 30 4x5 prints. The chemicals I bought will do approx. 200 4x5 prints (with some leftovers) and does not cost anywhere near 7x the price of the kit. The other difference is, well, most of the chemicals. The way I do it is considerably different from their way. But I guess that's part of the beauty is the number of different ways to make a Kallitype.

Obviously there is a lot of mixing to be done. Here's a lesson from high school chemistry. Start with distilled water; about 3/4 of the total volume you need. Add chemicals. Mix to dissolve. Top off with water to make your final volume. Also, a lot of these are percent-solutions. Like a 10% solution of Silver Nitrate is 10g Silver Nitrate with water to make 100mL. A 1% Sodium Sulfite solution is 10g with water to make 1L. Make sense?

I use a total of eight different solutions. Sensitizer solution A and B, developer, restrainer, clearing bath, toner, fixer and hypo clear. 

Please don't sue me. To prevent yourself from having a reason to sue me, wear appropriate safety gear for mixing and working with chemicals. Some of this stuff is rather nasty and will burn you, blind you, cancer-ize you, or make you cough a bunch. They might also help burn your house down. Each of these has a MSDS (material safety data sheet) available on the internets. Gloves are a must; I use black nitrile because I like to be fashionable. Eye protection is also advisable. Respirator. Chemical apron. I think I already posted on this so read it if you haven't.

Making stock solutions:

There are two parts to the sensitizer that are made as stock solutions and then mixed in equal parts just before use. I mixed these under a red safelight and keep them in amber glass bottles. Might be overkill but I'm not taking chances because these are pricey chems. Be careful with silver nitrate because it will stain skin brown and can possibly blind you should you get it in your eye. And its a strong oxidizer so it will help to make a small fire a really big fire. Ferric Oxalate is quite toxic too so handle with care.

Sensitizer Solution A
10% Silver Nitrate solution

Sensitizer Solution B
20% Ferric Oxalate solution

With the chemicals I bought I could make 100mL of each solution. That's 200mL working solution, which will coat 200 4x5 prints or 100 8x10s. That's a shitload of printing. Since the chemicals last much longer in powder form I only mixed up a quarter batch, making 25mL of each solution. 

Ferric Oxalate is a bitch to get into solution. When you mix your powder into the water if forms what can be best described as a slurry. Like you had a milkshake made with sand, and now it's melted. Gritty milk. At this point you have two options. Stick it in the microwave for a while and shake a bunch. I don't recommend this. To me there is something inherently stupid about nuking toxic chemicals where I also make my burritos. The alternative is option two. Patience. Mix the powder and water. Shake the hell out of it until you get pissed off at the lack of progress and then go to bed. When you wake up it will have gone from gritty milk to clear liquid. Magic. But don't get all excited and try to use it. Keep waiting. I tried making my working sensitizer about 20 hours after mixing the stock solutions. The Ferric Oxalate looked clear, but when I added the silver nitrate it formed a precipitate and I was left with a mini aquarium. Sand on the bottom, liquid on the top and a fish. (I'm lying about one of those 3 things). My second attempt at mixing a working sensitizer was about 48 hours after mixing the stock solutions. This worked much better. No precipitate formed. Lesson learned: Ferric Oxalate takes forever to go completely into solution!

The rest of the chemicals are boring in comparison.

Restrainer stock solution
5% Potassium Dichromate

The restrainer will help to boost contrast. I use 7mL per liter of developer. Your mileage may vary, different strokes for different folks, or any other cliche you feel like applying. This gets added to the developer, not the sensitizer. 

Potassium dichromate compounds are carcinogens, toxic, skin irritants and oxidizers. Do not taunt potassium dichromate. 

20% Sodium Citrate solution

There's room to experiment with the developer. Different developers will give different print colors which will be affected further by toning choice. This is an un-toned print with sodium citrate. It's a nice warm brownish black. There are other developers that use things like Rochelle salts, borax, tartaric acid and sodium acetate that all give different results. I'll try them out later.

The developer will need to be refreshed after a while. I've done 6 or 7 8x10's with no problems and I'm not sure how far I can push it.

Clearing Bath
3% Citric Acid solution

I haven't run into problems clearing prints with a single bath. The clearing agent can also be divided into a two bath the same way you would use a two bath fixer when doing silver gelatin prints. When the first bath gets funky, make the second bath the first bath and use a fresh second bath. I mix this fresh before each printing session and so far have had no problems getting the print to clear.

750mL distilled water
50g Sodium Thiosulfate
10g Sodium Carbonate
2g Sodium Sulfite
Distilled water to make 1L

Finally something that's more than one chemical. Mix in the order listed. I mix a fresh batch after every 2 or 3 printing sessions so I'm not sure what the actual capacity is.

Hypo Clear
1% Sodium Sulfite solution

Word on the street (internet) is that you can use standard Kodak Hypo Clear or equivalent. Haven't tried that yet but it makes sense. It's doing the same thing (chemically) that it does with film and silver gelatin prints. This is another one I mix fresh before every printing session.

This is where it gets expensive. The toners are noble metals that replace most of the silver in the print. Not only does it alter the color, but it also improves the archival qualities of the print. The standard choices are platinum, palladium, gold, and selenium. Apparently you can also tone with uranium but, I mean, seriously...uranium? Really?

The only toner I've tried so far has been gold. I've gotten results ranging from super-deep purplish black to pink. I like the deep purple but could do without the pink. I haven't really found the secret to consistent toning results.
Gold toned.

I chose gold because it was relatively cheap. I love the look of platinum toned prints but at $40 a gram I'd better be able to snort the stuff, too. Palladium is about $25 a gram. Gold works out to about $10. Selenium is dirt cheap in comparison. I'll hoping to try that next for some more neutral tones. (Selenium doesn't actually replace the silver. It converts metallic silver to  silver selenide which is supposedly more archival. Kodak Rapid Selenium Toner and other brands should work fine.)

Gold Toner 
150 mL distilled water
1g Citric Acid
1mL 5% Gold Chloride solution
Distilled Water to make 200mL

I mix this just before printing. I use just enough to cover the print and discard it afterward. I'm still trying to find a way to get consistent results.

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