Mercury Intensification

nworth · Aug 1, 2007

Sale of mercury componds is severely restricted almost everywhere these days. Disposal of anything containing even traces of mercury is also highly restricted and regulated. Mercury compounds can be used safely, but mistakes can be disasterous, and the regulatory climate is not friendly.

Mercury intensifiers were often called for when a high degree of intensification was needed. The results were not permanent, but they apparently produced quite printable negatives. For extreme intensification without mercury's problems, you might look into Kodak's IN-6 quinone-thiosulfate intensifier. It is supposed to give the most intensification of any of the breed. The results are also not permanent. If your needs are more modest, you can try selenium toning or one of the commercially available intensifiers.

Dave Krueger · Aug 1, 2007

nworth said:
For extreme intensification without mercury's problems, you might look into Kodak's IN-6 quinone-thiosulfate intensifier. It is supposed to give the most intensification of any of the breed. The results are also not permanent. If your needs are more modest, you can try selenium toning or one of the commercially available intensifiers.

Interesting. I found a forum post (on some other site) to the effect that IN-6 is the most extreme of the intensifiers and I also found the formula in a Kodak radiography document. Looks like the ingedients don't cost an arm and a leg, either. But it does require the negatives to be hardened first using Kodak "Special Hardener 1" (SH-1).

psvensson · Aug 1, 2007

I used Agfa 600 intensifier with pretty good results - about a 2-grade increase after ten minutes:

500 ml boiled, cooled water
citric acid 1.5g
hydroquinone 1.5g
silver nitrate 2.5g

Fix afterwards.

Dave Krueger · Aug 2, 2007

gainer said:
I would rather bleach the negative in a ferricyanide-bromide solution and redevelop in any of the staining developers.

Oops. I missed this. I zeroed in on the PMK suggestion and overlooked your more general recommendation. I don't use PMK, but I do have Pyrocat. So... That should do the trick, huh? I also have ferri for use on prints with the hypo in a different bottle. So... Sounds like I should try bleaching and redeveloping in pyrocat as a start (since I already have these) and see how much of an increase I can get from repeating the process. Somewhere I read that the ferri, by acting on the siler, but not the stain, will allow repeated cycles to build additional intensification.

Dave Krueger · Aug 2, 2007

psvensson said:
I used Agfa 600 intensifier with pretty good results - about a 2-grade increase after ten minutes:

500 ml boiled, cooled water
citric acid 1.5g
hydroquinone 1.5g
silver nitrate 2.5g

Fix afterwards.

Looks like kind of a hybrid of silver intenisfier and the IN-6 mentioned above.

CBG · Aug 2, 2007

Just a couple of thoughts...

Would it be possible to make a dupe neg and sandwich the two after to get a major increase in contrast and density with no exposure to supernasty materials?

Several advantages would obtain: safety, no messing up the original, the ability to redo till it's right, or walk awy with original unharmed.

Another vague possibility, theres a somewhat obscure toning method called FSA Toning - I don't know the particulars, but if I get it right, FSA toner is said to be able to build the appearance of greatly increased density on a print through redipositing a more finely dispersed silver image. Whether that would be usable on a negative or not, I have no clue. Would be interested to see if anyone has real knowledge of FSA Toning.

I'm just wary as heck about mercuric chloride, cyanides and the nastier elements of intensifiers.

Best,

C

Kino · Aug 2, 2007

Neanderman said:
I'm sure you've heard the term "mad as a hatter?" It referred to the mental instability that resulted from their occupational work with mercury when making felt. I'm sure if it had rolled off the tongue as well, we'd have a term "mad as a Daguerretyper" too.

My fathers cousins owed their "career path" to Mercury; the Norris Brothers, Pete and Paul (aka Pete an Paul Taylor) began to rob banks during the Great Depression because their mother, who was a hat maker with JC Penny in Oklahoma City, went bonkers from the Mercury and began complaining that the Great Depression wasn't "any fun" any more like the 20's were, so she demanded they bring in more money to the household.

Naturally, being from Oklahoma and all, bank robbing came to mind first.

They finally "retired" when a payroll heist in Fort Worth Texas went bad and Pete was emulsified by the FBI. Paul spent the rest of his life in and out of prison, visiting Alcatraz for 10 years and then finally passing in the Huntsville Penitentiary in Texas.

I remember the funeral in the late 1960's when I was a small boy.

Grandpa Frank

DBP · Aug 2, 2007

There has also been discussion among historians of science that Newton's career and intellect was diminished by exposure to mercury during his alchemical experiments. One wonders whether, given undiminished capacities, he might have followed up the invention of calculus and discovery of the laws of motion with something else that took a few more generations without him.

Dave Krueger · Aug 3, 2007

Well, I appreciate everyone taking the opportunity to share their horror stories about how humanity narrowly escaped extinction due to mercury poisoning, but not a single soul actually proferred an answer to the question posed by the original post. I appreciate the lecturing, but it gets a little old after a while, especially when everywhere you turn these days, you're confronted by someone who adamently insists they know more about how you should live your life than you do.

I'm happy to report, however, that I actually got to work this morning without being trapped in a single bridge collapse. With luck, I'll manage to get through this month without being in a plane crash, turning into a meth addict, cutting off my fingers on the table saw, or suddenly ingesting a mouthful of selenium, all without any unsolicited advice blindly volunteered by people out to save me from myself (or divert me from my evil plan to destroy the universe).

Thanks to the people who offered suggestions about alternatives to mercury toning, but now I'm outa here.

Kino · Aug 3, 2007

Marc . · Aug 3, 2007

Dave Krueger said:
Well, I appreciate everyone taking the opportunity to share their horror stories about how humanity narrowly escaped extinction due to mercury poisoning, but not a single soul actually proferred an answer to the question posed by the original post. I appreciate the lecturing, but it gets a little old after a while, especially when everywhere you turn these days, you're confronted by someone who adamently insists they know more about how you should live your life than you do.

Hello,

Sorry I can't help with mercury chloride sourcing or the negative mercury intensification, but consider reading the Safety Cards below and good luck !

http://www.cdc.gov/niosh/ipcsneng/neng0056.html
http://www.epa.gov/ttn/atw/hlthef/mercury.html
http://ptcl.chem.ox.ac.uk/MSDS/ME/mercury.html

Marc

phritz phantom · Aug 3, 2007

just read the story of stan brakhage, who worked with carcinogenic dyes.

gainer · Aug 3, 2007

Dave Krueger said:
Oops. I missed this. I zeroed in on the PMK suggestion and overlooked your more general recommendation. I don't use PMK, but I do have Pyrocat. So... That should do the trick, huh? I also have ferri for use on prints with the hypo in a different bottle. So... Sounds like I should try bleaching and redeveloping in pyrocat as a start (since I already have these) and see how much of an increase I can get from repeating the process. Somewhere I read that the ferri, by acting on the siler, but not the stain, will allow repeated cycles to build additional intensification.

It can be repeated, but these staining developers are also tanning developers and repeated tanning can cause cracks in the emulsion. In any case, the negative must be thoroughly fixed and washed before BRD. Any unfixed halide will show as a blemish after redevelopment. Any remaining fixer will react with ferri to make Farmer's reducer, which is the opposite of what you want. I'm sure you know these things, but some reading here may not think of them. I should have thought about them, but I learned the hard way.

Ole · Aug 3, 2007

Dead Link Removed

I buy my chemicals from VWR international.

jeroldharter · Aug 3, 2007

I have seen people with toxic levels of mercury and can tell you that using mercury compounds is a bad idea. No mad hatters on APUG. Maybe you should use Photoshop at that point. Short of that, the people here have given you a number of ideas.

reggie · Aug 3, 2007

Monophoto said:
A few years ago, I was in a workshop with a famous photographer who had worked extensively with mercury intensifiers. He gave us a demonstration of how it works.

Unfortunately, a number of us noted that his speech showed signs of neurological problems. I think we all concluded that while the technique was probably pretty powerful, we were not willing to accept the risks.

If exposure and development is done correctly, you don't need mercury intensification.

Did the photographer happen to be George Krause? I'll check Drakroom again, but I seeem to recall that it was him.

-R

Mercury Intensification

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