Cold mercury development problems

[Dafna Gazit]

Hi

Here are photos of my first three 4X5” multiply coating and cold mercury developed Dags.

As you can see it didn’t go very well.

Following John Hurlock’s article “WARMING UP TO COLD MERCURY”,

I fumed the plates over Iodine for thirty seconds until a yellow-rose color then I fumed the plates over Bromine in calcium hydroxide for thirty seconds until it had a steel blue hue. At this stage I noticed that the surface was not homogeneously fumed.

Then I fumed the plate over Iodine for thirty seconds under a red light.

I exposed one of the plates in the camera for 90 seconds at EV=13. For The other two I tried studio strobes at EV 17.

Then I put the 3 plates in a good quality vacuum desiccator at 27 inch vacuum. After the first 6 hours I checked for an image under red light and there was none. I removed them from the desiccator after 24 hours.

I released the vacuum from the desiccator very slowly.

 

I fumed the plates about a week before I took the shots (I don’t know if its relevant at all).

Can anyone tell me what had happened here? I am really in the dark, I have no idea what I might be doing wrong.

 

Thanks

 

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[jgmotamedi]

I fumed the plates about a week before I took the shots.

I know little about the cold mercury process, but I suspect that your problem is probably largely a result of fuming too long before development. Try to fume no less than an hour or two before exposure.

[photolytic]

Dafna,

It looks like you have a partial image on the first and last plates.

First of all, assuming you fumed at 20C, your Iodine fuming may be too long.

When the plate coating is very thick it can obscure the image, making it hard to see under red light.

Ten seconds over iodine (to yellow with a trace of red) followed by 10 seconds over bromine (to a redder yellow) should be enough. More time, up to 20 seconds over bromine, may be required if the quick does not contain enough bromine.

After the bromine, fume the plate for 5 to 10 seconds over the iodine under dim white light (to a violet rose) and then for 2 to 5 seconds more over iodine under your red safelight.

Fumed plates will not keep for a week. After a day spots and swirls start to appear.

Silver iodide and bromide are very stable in the dark and not prone to loss of halide or “out gassing”.

Only exposure to stronger halide gasses like chlorine or fluorine can displace the bromine.

Possible adsorption of silver halides by residual lampblack or other polish residue left on the plate is a likely cause for spots.

Some say old plates can be refreshed by more fuming but I think it’s best to start over.

Lower storage temperatures and humidity will slow this aging process but eventually time will take its toll on the plate.

Another possibility is that the plates have come into contact with some moisture although that seems less likely in Israel. Maybe there is some water in your iodine or mercury. Try putting some silica gel in your vacuum desiccator.

Good luck,

John

[Dafna Gazit]

Thank you both 🙂

Regarding the dust traces on the plates – I think it was caused by the calcium hydroxide. ..

Is there another substance for mixing the bromine with?

Dafna

 

[photolytic]

I’ve never had a problem with calcium hydroxide dust but if you are concerned you can use silica gel.

See Mike Robinson’s post on this subject.

Wiping the polish residue from the back of your plate will prevent getting any into your fuming box. Vacuuming the fuming box drawer and the inside of your plate holders frequently will prevent dust deposit there.

To examine the developing plate inside the desiccators you need a directional red light you can shine on the plate at a low angle. A regular flashlight with a rubilith filter taped to the end or a red LED flashlight work well.

[Dafna Gazit]

Thank you John, I have found Mike’s post and I will try it.

[Dafna Gazit]

Finally a reasonable result with cold mercury development.

As you can see one of the plates was underexposed (portrait using indoor lighting), while the other was a little overexposed (outdoor natural lighting).. but at least finally I have something to work with.

In an attempt to prevent “dust spots” on the plates, instead of using calcium hydroxide for the bromine, I charged silica gel with the bromine (it took several hours to charge).

In both plates (mostly in the underexposed portrait) there are still traces of dust-like-spots.

Obviously the calcium hydroxide did not cause the “dust spots” in the former plates for they occurred in theses plates as well.

Can anyone tell me what is causing it and how I can prevent it in my future plates?

Many thanks

Dafna

 

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[Dafna Gazit]

…the second plate

 

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[photolytic]

Dafna,

Good progress. Try blowing the dust spots off the plate with one of those dust blaster rubber bulbs. Another technique is to invert the plate and rub it polished side down on a clean buffing paddle to wipe the dust particle off before fuming.

All the best,

John

[Dafna Gazit]

Hello again

lately (past 2 weeks) all the plates I try to develop in cold mercury are turning out like this(sample attached).

befor that I had succees in making cold mrcury development.

I cant figure out what went wrong. my desiccator is a good one that holds the vaccum for many hours. after few times like that I have added cilica gel to the desiccator because the humidity here is 60%. but it didnt help.

because of that I returned to the conforting Becquerel development.

Any suggestions?

Thank you,

Dafna

 

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[photolytic]

High Dafna,

Things to try.

Reduce the bromine fuming level.

Mask the plate and try several bromine times on a single plate.

Use less developing time.

Inspect with directional red light during developing.

Too much can fog the plate so use caution.

Best to keep plates out of any light during the developing process.

Check for worn areas on your plates.

Plates should appear evenly coated during the final inspection during fuming.

Ghost images indicate incomplete removel of previous images.

Good luck, John

[Dafna Gazit]

Hello John

Thanks for the advices.

I am trying to reduce developing time. I think that the hot and humid weather here had changed all my measurements and I can’t get it developed properly since.

I bought a polycarbonate desiccator- should it work exactly like the glass one or a little beet different? I think it can’t hold the vacuum for a long time. Do you have any tips for using it?

And one more question- is it possible to develop single sensitized (iodine) plate in cold vacuum?

Thank you

Dafna

[photolytic]

Hello Dafna,

I started out using a polycarbonate desiccator but it didn’t hold a constant vacuum. I tried re-evacuating during development and applying some vacuum grease to the rubber gasket but nothing worked very well. Often the plates came out blue due to under developing.

Yes you can develop single iodide plates with cold mercury.

The images come out very strong with high contrast.

This is probably a good place to start before you try using bromine again.

Concentrate on your developing technique first then gradually add bromine to the process.

[Bakody]

Hello John,

Yesterday I made my first vacuum developed mercury dag. The result wasn't too good. Actually I could see just the shadow of the object in the image, but I know what was the problem: I need to have much more development time.

I would like to ask the flowing thing:

In Hungary the winter is coming, the temperature will drop down soon. It's already around 20C. I saw it somewhere that over 21C mercury fumes increase fast in the air. Do you have any experience with temperature less then 20C? How will mercury fumes change in the temperature like 15, 10, 5C?

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[photolytic]

You may also have to increase the exposure time. Remember that the speed of a mercury developed iodized plate is the same as a Becquerel plate which is approximately 60 times slower than an iodine/bromine plate so just substitute minutes for seconds and you will have the correct exposure.

As for the mercury temp, I would not let it cool below 15C. Mercury vapor pressure at 10C is 0.00049mmHg or approx 40% of the Hg's vapor pressure (0.001201mmHg) at 20C. To compensate for this you would have to increase your development time by about 2.5x or 5hrs at 27in Hg.

You could also increase your vacuum to 28 to 29 inches of hg

[Bakody]

Thank you for your answer!

I calculated with the Becquerel exposure time.

I will try to make a couple of new images this weekend. I will let you know how good is the result.

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[Bakody]

This was my third try with vacuum development.

temperature: 17C

vacuum: -0.96bar

development time: 5.5h

On the picture you can see, what I can see from my window.

I had to lover the position of the plate, closer to the mercury. Compare to the plate size, my vacuum chamber is big, so I put the mercury in a low glass plate and I put it in to a small plastic container. My plate is just fir in the container. So like this I can concentrate the mercury fumes to the plate.

It's a little bit dirty because of the quick washing.

Is this plate overdeveloped? What is in the middle of the picture (huge white spot)? Why is it there?

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[photolytic]

The spot is caused by a large mercury droplet falling on the plate. This can happen with hot mercury also. Movement of the desiccator during development can be the cause.

Always face the plate down so mercury cannot fall onto it from the top of the desiccator. Do not put the plate in contact with the mercury bowl. When you pour the mercury out of the bowl it may leave tiny droplets of Hg on the rim of the bowl. I have developed both large and small plates in the same large desiccator and have not seen much difference in development time.

5.5 hours at 17C seems too long but the plate does not look overdeveloped.

[Bakody]

Today I had time to make 2 images on the same test plate like before. You still can see where was the white mercury spot, but it's lighter and lighter…

Street view:

temperature: 17C

vacuum: -0.96bar

development time: 4h

Lettuce:

temperature: 17C

vacuum: -0.96bar

development time: 3h

Little bit overexposed.

I think 3 hours of development is not enough. Something still wrong in my process, because in one side the image is black.

I wanted to ask how to make blue solarization, but I found the answer in the forum: I need to use thinner iodine coating (yellow-rose). Now I'm using purple.

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[photolytic]

Once you get a mercury spot on a plate it requires a double buffing to remove all traces of the mercury residue. Before that happens these traces of mercury leave an area that is less sensitive. One technique to remove traces of mercury is to "burn the plate". You can do this by heating it in an old electric frying pan to 150C to evaporate all traces of mercury before the final polishing. This must be done outdoors to safely disperse any mercury fumes coming from the plate.

[Bakody]

"water lily" http://www.facebook.com/photo.php?fbid=401445699922687&set=a.371776002889657.82853.371771479556776&type=1&ref=nf

On the same plate what I used before, my first acceptable mercury developed daguerreotype! It's a little bit over gilded, but I keep it. I still couldn't get blue solarization, but I will keep trying. Do you have any advice? Yellow or yellow-rose colour for iodine and maybe shorter development time?

Video: http://www.youtube.com/watch?v=31ohTar25Vg

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[photolytic]

I like the slightly brown colors on your water lily Dag.

Is that cold or hot mercury developed?

Most of my experience with iodized plates is with Becquerel development.

I found that Iodizing to a magenta color (40=60second@20C) or a blue color (70-90seconds) worked faster than iodizing to a yellow-rose color (15-20 seconds), but I was not looking for solarization. Your best conditions to create blue colors are to increase the exposure and shortening the developing time.

[Bakody]

It's cold mercury developed dag. I can make just cold mercury developed dags.

I usually iodizing for magenta, purple.

So I will increase the exposure and make shorter developing time.

Thank you!

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[photolytic]

The tones are wonderful.

My wife has water lilies too but it is getting too cold for them to bloom here.

I think that you are ready to add bromine to your fuming.

For solarization and high contrast, keep the bromine to a minimum.

The fuming time will depend upon how much bromine is in your quick but 8seconds @ 20C is usually enough. You should see a color change (rose-violet) after the second iodine fuming.

Best of luck, John

[Bakody]

Thank you John!

At the next 2 weeks I wont have time make new dags, but I will order bromine soon.

After hen I took the picture about this dag, some yellow-white spots came out at the top, where the water is overexposed. Nothing serious, just in a small area.

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

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