From: Phillip Murphy (pmurf@bellsouth.net)
Date: 10/09/02-11:32:05 AM Z
Jeff Sumner is correct; various coatings have been attempted over the years with
little success. Glass remains the preferred method of sealing a plate.
However, I also deeply enjoy the pristine clarity of a naked plate... It is
unique. The answer to your question lies in metallurgy. In the early days of
the Daguerrian era , the use of the electro-galvanic cell (the battery) was
widely experimented with. One clever technique was to copy relief objects, that
were coated first with a conducting medium (usually a form of graphite), using
copper. In these days, you would google "electroforming" as a search for
information and find that a very fine copper "paint" is used for the conductive
medium. (think...bronze baby shoes) In the early 1840's, realizing that the
Daguerreotype plate has a relief surface, someone hit upon the idea of
electroforming on the surface of the Daguerreotype with copper. When this was
carried out until the copper had reached the thickness of a card, the copper
plate was carefully removed and the result was that the Daguerreotype was
replicated in all it's perfection. These plates were hailed at major
exhibitions for their beauty and delicacy of tone. Very few examples can be
found today. (as an aside: this is the very technique that Woodbury used in the
original Woodburytype plate making) Also, very little energy is needed to
electroform copper. A group of rechargeable "D" cells is plenty and you can have
several plates forming at the same time using a several copper sulfate baths
connected in series.
Now this is how one thing leads to another: When you electroplate or
electroform with copper, one thing you notice about copper is the variety of
colors that the metal can assume under various conditions. A man by the name of
Charles G. Page decided to exploit that quality by devising a way to "color"
Daguerreotypes using varying thickness' and combinations of solutions of copper
to create the colors. He was somewhat successful with this and I believe even
had the method patented. These days, that technique is referred to as
pen-plating.
One thing Page discovered in his experiments is that when he electroplated an
extremely fine coating of copper on the Daguerreotype surface, it brought more
brilliance to the plate than even gilding does. The more interesting thing,
however, is that it also had the property of "hardening" the surface of the
plate. So much so, that it could be handled readily without damage. The story
goes that he carried one around in his pocket for over a month without damage.
A plate was kept open to the atmosphere for over a year without any apparent
change. He even rubbed it with a tuft of cotton without damage..
I've always felt that this technique might prove to be a great avenue for
Daguerreotype experimentation.
My choice would probably not be copper but perhaps Rhodium, which is a very
bright white metal that creates a very tough surfacing.
No time for experimenting these days for myself.... I am usually wrangling
pixels all day. heh.
Good luck on your quest Christopher. The Daguerreotype hasn't even begun to be
explored for new possibilities.
Christopher Lovenguth wrote:
> I've been trying to think of a way to seal a daguerreotype plate with some
> sort of substance so that I don't have to have it under glass. Can anyone
> think of a way to do this? I don't want it to alter the finish so it would
> have to be some sort of material/chemical that can be applied without
> severely affecting the finish. It will have to be neutral as well in order
> not to tarnish the silver. Third it would have to be able to be applied
> carefully because the slightest touch destroys the image. So I'm thinking a
> sort of liquid that I can either dip the plate in or spray the plate with.
>
> I couldn't come up with any ideas that I'm just willing to try. It's not
> that I want to be able to put my paws all over the image and then be able to
> use window cleaner to wipe them off. But I like the quality of just the
> plate without glass. The problem is showing it to someone who might not
> understand that just the slightest touch will ruin it. Plus transportation,
> my own viewing (I'm very clumsy) dust, etc. Right now I have been using
> neutral plastic film holders sheets. But even with those if you take the
> plate out of them a couple of times start to scratch the image because of
> dust particles. Just keeping the plate in the sleeve and looking through it
> you lose subtle qualities.
>
> This is not as much of an issue with some of my gilded plates. For some
> reason some of them have become almost touchable. The thing is I'm sort of
> select gilding my plates now since a long time in the gold tends to darken
> my plates too much. I'm now taking my plates out a bit faster then I used to
> because I like the quality and effect, but these images are more fragile and
> can be wiped off with the slightest touch just like the plates that haven't
> been gilded.
>
> I'm willing to experiment with a bad plate so suggestions are appreciated.
> -Chris
>
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