Mercury Intensification

[Dave Krueger]

Anyone know a good place where I can get mercuric chloride to make mercury intensifier for negatives?

 

[Pinholemaster]

Won't that make your darkroom a SuperFund site?

You sure you want to be working around mercury?

 

[Robert Hall]

Have you considered PMK and a dichromate bleach for neg intensification?

 

[Ole]

This is one of the simple, yet difficult answers:

If you don't know where to get it, you are not supposed to get it. I would also recommend that anyone who doesn't "just happen to have it" drop every though of ever getting hold of it!

The reason for this is that it's just too dangerous to use unless you know exactly what you're doing. And if you do know, then you probably have a degree in inorganic chemistry. with that education you should know where to get the chemicals, too.

Robert hall suggested dichromate bleach and a PMK redeveloper. That's a good advice, even if I'd prefer Pextral's two-bath as a redeveloper. you get contrast ranges with that which you would never get with mercury!

 

[Trask]

FYI, there's an interview with a guy who used mercury intensification in the book "Darkroom" -- though I've got to admit that I'm willing to forego any alleged benefits of using a mercury intensifier because the stuff scares me nuts.

 

[Paul Howell]

Anyone know a good place where I can get mercuric chloride to make mercury intensifier for negatives?

If you are in the US I think you need a special permit from the EPA or OSHA to buy mercury products?

 

[Monophoto]

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.

 

[gainer]

I would rather bleach the negative in a ferricyanide-bromide solution and redevelop in any of the staining developers. If all you care about is that the stain increases contrast, you can use hydroquinone without sulfite as a staining developer. Any of the ready made staining developers will increase contrast on graded paper and on VC paper as well with a modicum of magenta filtering. Using a staining developer restores the original silver density while adding to it the colored stain that is proportional to the silver density. With VC paper you then have more control over the printing contrast than you would with the mercury intensifier. This is of course only my opinion. I have tested it and reported it some years ago in Photo Techniques (then it was Darkroom and ) and it works.

Ferricyanide sounds worse than it is. You are not likely to find an accidental way to liberate cyanide gas from it. The bleach that is used with sepia toning of prints is suitable. The sulfide toning though does not add much if any density but replaces the silver by silver sulfide.

 

[gainer]

I forgot to add carbonate to the hydroquinnone. It won't last long, but it works. Proportions are not critical. Lack of sulfite is important. Sulfite is why you never hardly ever see a stained image from PQ.

 

[Dave Krueger]

Hmmm... I take it the answer is no.

I believe that disasters can be avoided by being careful. Perhaps I already have "neurological problems". Just bury my reckless dead body in the same hole with all the vitims of tooth fillings, asbestos, breast implants, and people who don't wear seatbelts.

I don't know that mercuric chloride is unavilable in the U.S. I had already bookmarked a couple suppliers before I even posted, but I thought there may be others who do it and have a preferred source. From what I gather, no one reading this thread has used it.

Of course, I certainly wouldn't mind an alternative that provides the same degree of contrast increase as mercury intensification, even if it's not reversable.

 

[Paul Howell]

Of course, I certainly wouldn't mind an alternative that provides the same degree of contrast increase as mercury intensification, even if it's not reversable.[/QUOTE]

I use both of Photographer Formulary intensivifers, chromium and silver with good results.

 

[Uncle Goose]

I used to work with it, but not photographic related. I advice to stay away from any loose mercery as it's very dangerous on the long run. When I worked with it I had to wear a gasmask with special mercuryfilter and in a special space with air suction. That's the least you must have to get rid of the fumes. But the real problems start when you accidentaly spill it, without a special vacuumcleaner it's almost impossible to get completly rid of it and it will slowly poison you. Extensive exposure can results in loss of theeth, speech problems, spasms, loss of muscle control and a hell of a lot other neuro problems. In Europe the use is extremely restricted and you need a permit to buy it.

 

[Dave Krueger]

Robert hall suggested dichromate bleach and a PMK redeveloper. That's a good advice, even if I'd prefer Pextral's two-bath as a redeveloper. you get contrast ranges with that which you would never get with mercury!

I've read about dichromate bleach and redevloping/toning. I have potassium dichromate on my shopping list as well. But, I didn't get the impression that it could increase the contrast the equivalent of five paper grades like mercury can. PMK can do that?

 

[Ole]

I don't know about PMK, but I do know that a negative that needed a G5 graded paper printed nicely on POP after bleaching followed by redeveloping in a Pyro/lye soup. That's a longer range than a G0 graded paper; the total contrast range corresponds to the full scale of my 21-step Stouffer step wedge.

 

[Jim Chinn]

Selenium can also be used. Depending on the film you can get about 1/2 to a full stop.

 

[gainer]

I used mercury many years ago when you could buy opiates for teething children.
The redevelopment by staining developer is not reversible, but its effects can be varied by filtration if you use VC paper. The effects of mercury on the body are IIRC accumulative. W. Eugene Smith was severely beaten for his photo essay on the ravages of mercury in fish contaminated by an industrail plant and eaten by Japanese. Most of the hazards of our photo darkrooms can be washed away from inside and out. Even if I could still get mercury compounds with the former ease, I would not, even if just to memorialize Mr. Smith.

 

[Neanderman]

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.

 

[Dave Krueger]

I used mercury many years ago when you could buy opiates for teething children.

Ah, dem were da days...

How about silver intensifier? At first glance, I didn't think it would deliver the increase in contrast that I wanted, but after browsing the web for a bit, I'm beginning to think maybe it's capable of several paper grades.

Then I stumbled upon an outfit called Speedibrews which has some interesting products. Anyone know if their products are distributed by anyone in the U.S.?

 

[Paul Howell]

Ah, dem were da days...

How about silver intensifier? At first glance, I didn't think it would deliver the increase in contrast that I wanted, but after browsing the web for a bit, I'm beginning to think maybe it's capable of several paper grades.

I use the PE version, works well for me. I also found a formula for a Copper Iodine Intensifier in Carroll's update of Photographic Facts and Formulas, with a referance for a 3 stop intensification per treatmet.

 

[Dave Krueger]

Selenium can also be used. Depending on the film you can get about 1/2 to a full stop.

Selenium is definitely an option since I keep it on hand anyway, but I'm really looking for more than a single grade increase in contrast.

 

[gainer]

To get 5 grades, I would do the pyro thing, then photocopy the negative through a blue filter, then photocopy that positive to another negative with ....you get the picture. If you want, you can use litho film and wind up with a silhouette (sp?).

 

[Dave Krueger]

Wow. I came across something called MONCKHOVEN'S INTENSIFIER (Ilford I.In-4) which contains not only mercuric chloride, but potassion cyanide. That must be from back in the days when photographers were lucky to live long enough to graduate from high school.

 

[Dave Krueger]

Then there's uranium intensifier which is apparently quite potent. Also previously available from Ilford. But, alas, it contains uranium nitrate which is even harder to get than mercuric chloride...

 

[Brook]

You can use a silver intensifier over and over to get the CI desired, within reason. But do consider that every time you get the neg wet, you risk damaging it.

 

[Dave Krueger]

To get 5 grades, I would do the pyro thing, then photocopy the negative through a blue filter, then photocopy that positive to another negative with ....you get the picture. If you want, you can use litho film and wind up with a silhouette (sp?).

I was hoping to avoid the lith route. I think the most promising proposal has been the dichromate bleaching and redevloping, although I plan to look into the silver intensifier a bit more...

I really need to get past my mental block about making contact negatives for stuff like this as well as contrast masks, etc.