low contrast in dag

[pruts]

Hopefully someone over here can help me.

At the moment i am testing a new mercurypot 8×10 and new plates.
After 2 days full sun light ( EV 15) my dags still have low contrast and look a bit shallow.
Changing the time for I-fuming and Hg-cooking is not helping;
Changing the Br-fuming gives no change .. except chalky mist over the plates.
I suppose I have a filmspeed about 0,006 ISO.

So I am looking for brighter image and higher contrast.

thx

[CasedImage]

Pruts, can you give us some more info to help with the problem solving
– what dags have you made before -becquerel?
– can you describe the steps in your polishing technique?
– what colour are you aiming for with the Iodine?
– How are you determining the bromine exposure?

www.CasedImage.com

[photolytic]

Alan’s points are well taken.
High bromine levels may increase the ISO speed but also reduce the contrast and cause haze.
Reducing the bromine exposure a bit will increase the contrast but still leave you with a speed you can accept.

You don’t mention whether or not your images have been gilded.
Mercurial images are often quite dull before gilding especially if the mercury temp is too high.

New plates can be a problem.
Do you have any of your old plates to make a comparative test?

It is also possible that high humidity is responsible for the dullness especially if the time between exposure and developing is too long.

[pruts]

Thx for the fast reaction
I make Dag’s with mercury.
I put the silver on copper with elektrolysis : 11 minutes / 1Volt / 1Ampére. I do this aleady many years.
Polishing-method :
-polishing with excentric handpolishing machine with flanel and Nushine
-degreasing trough elektrolysis
-wshinh with white spirit
-washing with soap ==> drying with hairdryer
-small cleaning with alcohol and velours
-buffing old style with rouge and velours

-The colour I want with Iodine : FIRST COLOR CIRCLE ==> dark yellow with possible tint of magente
-The colour for bromine : deep magenta
-Second time for iodine : about 40 % of first time of iodine

I don not gild my images … also not in the past.

THe new factor in my method is a new mercurypot. It is a big one for maximum size 8×10 inch . ==> On the bottom I have a temperature of 75° – 76°C On top ( at the plate ) about 33°C. The plats are 8 minutes in mercurypot.

In tha past hours I already supposed that humidity can be a problem and one of the buffing-pads was not so clean anymore …

thx for the first reactions ….

Marc / Belgium

[photolytic]

Your silver plates seem to require much polishing and cleaning before the rouge/velour stage
Does your plating solution contain a brightener?
Are the silver plates dull before polishing?
I would avoid Nushine silver polish as it contains thiourea that has been demonstrated to cause staining on Dags.
If you do a dry polish with stick rouge you will not need mineral spirits and soap (really! saponified fat?).
Only a light alcohol wipe with an ethanol soaked facial tissue (use lotion free type) will be needed.
http://rkm-ltd.com/products/silver-polish/

After the rouge/velour polish you should use a lampblack/velour to remove the residual powdered rouge.
Finally you should use clean velour (velvet?) to remove all lampblack or it may cause black spots.

[pruts]

Hello again,
My plating-solution dos not contain a brightener and the plates are after slivering not shiny but matte-milky -white.
The nushine polis I use comes from the UK and was recommended to me bij Mike Robinson.

[Bakody]

My first silver plater gave me milky silver plated plates. My second silver plater gave me mirror bright silvered plates. I think because of the mirror like surface, he used brightener and I didn’t have any problem with those plates…
Just to study and understand more about silver plating: What kind of bath are u using to make silver plating at home?

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

[CasedImage]

Can you add pictures of your mercury pot?

www.CasedImage.com

[Mike Robinson]

Regarding NuShine. I believe there’s a bit of confusion regarding the NuShine polish. What I recommend is called NuShine II Grade S. It is supplied by Nuvite corporation in the US. The product is not water soluble, as is the UK product in the above link, it is diluted with mineral spirits. Nuvite provides several grades with different cutting power, and I only recommend the finest, S grade. The Nushine product from RKM seems to me to be a completely different product.

NuShine II has some sort of wax or the like in its formula. This is why mineral spirits are required. The soap afterwards helps to remove the mineral spirits/NuShine residues.

My polishing and cleaning system was designed to prepare my clad silver plates and is what I’ve found the most efficient to means to prepare them. Those that electro-plate may have better results with a different system.

Mike Robinson.

[pruts]

Answering Bakody: For the degreasing and silvering trough elektrolysis I use products of a German Firm WIELAND.
Reaction for Mike robinson: Sorry for the confusion on the polishing product :Yes it is NuShine II Grade S.

[CasedImage]

I’ve used the Nushine II S for many years on mike’s clad plates and never had any problems with staining even on extant daguerreotypes after many years. Never heard it happening to others either.

www.CasedImage.com

[pruts]

I take a break … a holiday in France is waiting … I want to say hello to Niepce …

At the moment the surfaces of my plates are smooth and shiny ( still degreasing through electrolysis after buffing the copper and for cleaning the silver using the NuShine II Grade S and washing with wite spirit).

At the end of august I’ll start electrolysing with my plates moving in the silverbath automatically. In that way I’ll control better the quality of the proces … till now I did it manually …

The image of the latest dag’s I get are not chalky/ milky anymore. I am still a little bit disappointed with the filmspeed … but that’s some bromine-trouble I’ll solve in september. The contrast is still a bit low but I understand now already how I have to change it, so that’s the next step to take together with having more control on the filmspeed.

Anwer for Casedimage: my M-pot is made of stainless steel ( pyramid upside down ) and is completely packed in isolating foam. The heating happens with a heating element 150W/220V. This is normally used for coffeepots. The temperature can be controlled at the bottom and I can check the temperature at the bottom and at the top of the pot. Everything stands in a fume hood.

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