Why people do not clad silver foil onto stainless steel?

[newone2010]

I discussed with the guy this afternoon.He said there is another way to put pure silver onto cooper.The method was very very old.Chinese workers used this method 1500 years ago.

Mixed the silver(or gold) and mercury,then put the mixture onto the cooper.The mercury escape from the mixture and the silver(or gold)left after heating. Repeat it 4 times,and it will left about 36 microns silver on the surface.

The ancient Buddhism sculptures were made by this method.

How about modern Daguerreotypists do with the clad plates?Is it the same method?Can someone let me know some information about it?

Maybe prepare silvered copper is not a problem for you,but it really stuck me from further attempt.

Thank you all

[Mike Robinson]

Dear Newone2010,

I think your heading in the wrong direction here, but you’re not the first. Every daguerreian struggles with the problem of getting good plates.

Personally, I think that .001 m foil silver will not be nearly thick enough silver to withstand the rigours of polishing or provide enough bulk silver to form a bold, bright image. A few years back, the Daguerreian Annual featured an article on Samuel Bemis, a Boston Dentist in 1840 who attempted a few images on silver foil. Yes he got images, but they were not very good.

You can make a daguerreotype on a collodion wet plate as well. if you totally expose it and then buff the silver deposited in the film. Again it works, but the image will be extremely fragile and very very faint.

Depositing silver by evaporating mercury from amalgam is foolhardy. You might get silver on a plate but may kill yourself in doing it.

My clad plates have 25 microns on silver on them and after polishing, about 15 – 18 microns remain. I often re-silver my plates, but excellent images can be made on the clad plates without re-silvering. The have a roll mill finish, not bright until polished. Other posts here describe in detail my polishing method.

For info on how clad plates were made in the 19th century …..

The French method of plate fabrication begins with an approximately three by five by eight-tenths of an inch thick rectangular block of copper. Soldered to this is a thin sheet of pure silver only one-thirtieth as thick as the copper. The two fused metals were then passed back and forth between two workmen, significantly elongating and thinning the workpiece. A fifty-percent reduction in thickness would harden the metal preventing further reduction. To continue the work had to be annealed. The material would be taken through several cycles of rolling and annealing to render thirty-two, six by eight by one-twentieth inch plates, otherwise known as full or whole plates from the original block. The rolling mill imparts a curvature to the plate and roughness to the silver surface. To remedy this, the plates were carefully beaten with a planishing hammer to flatten and smooth the surface.

Modern clad plates are similar, except that the metals begin as long coils, are brought together by heat and pressure at the rolling mill to create the bond. They also go through about 5 cycles of thinning and annealing to reach the finished thickness. I get the material in long strips and cut them to length. The curvature is removed in a flattening roller method, not by planishing.

all best

Mike Robinson

[Author]

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