From: Richard Knoppow (dickburk@ix.netcom.com)
Date: 05/12/00-02:21:42 AM Z
At 08:27 AM 05/12/2000 +0100, you wrote:
>Hi
>
>Egad I suddenly realise the passage of time- I am actually old enough to
>have used this method of glazing- in fact I still have some glazed prints
>made at the time. Oh dear.
>
Previous thred snipped, it was getting long.
I must disagree about "genuine" ferrotyping being done on emameled
plates. The emamelled ones were cheaper than chrome. Enamel requires being
polished with wax. The typical ferrotype polish is a very dilute solution
of mineral wax of the sort called Paraffin wax in the USA. It is dissolved
in an alcohol or mineral solvent and a very thin coating put on the plates
and polished almost off.
Chrome plated plates do not require the wax. They need to be perfect in
surface and mirror smooth. The finish of the prints will depend on the
finish of the surface they are dried against.
Glass can also be used but I've never had much success with it. It must
be polished with fine talc (French Chalk) to fill in the pores and waxed.
Otherwise the gelatin will bond to it.
Chrome plates reqire only to be spotlessly clean. They should not be
waxed and must be cleaned with a non-abrasive cleaner. Even very fine
scratches will cause prints to stick and ruin the finish.
The older books recommend that prints to be ferrotypes be well hardened.
One even recommends the use of a formalin hardener but I think that is
unnecessary, an ordinary hardening fixer will do. Unhardened prints are apt
to stick or tear.
The prints should be well washed. They should then be soaked for a few
minutes in a solution of Photo-Flo. They should then be placed on the
ferrotype tins sopping wet and gently sqeegeed down. Cover the print with a
photo blotter and squeegee again to soak up the excess moisture. There is
some controversey as to whether a roller or straight squeegee is best but I
have had good results from both.
The tin with the print is then set aside to dry. It can be heated gently
to speed up drying but if the drying is too fast the print will not dry
evenly and peel off in parts leaving an "oyster shell" effect. Prints will
dry without heat reasonably fast. When dry the prints will pop off the tins
by themselves. At most they will need only to have a corner gently pried up
and will then pop off.
It was pretty common to use drum dryers with a ferrotype surface on the
drum. Glossy prints were placed on the machine with the emulsion side
facing the drum, matt prints with the emulsion facing the belt. I believe
shuch dryers are still made. The treatment of prints for drum drying is
about the same as for flat tins. The prints are soaked in Photo-Flo and put
on the dryer sopping wet. The action of the machine and belt act as the
sqeegee and blotter. Again, too much heat will result in uneven drying and
a poor surface.
The best glossy finish is not quite as shiny as an RC glossy but pretty
close. The glossy surface produces the widest tonal range possible from the
paper because it has the least scattering. Glossy type paper is made with a
thick gelatin overcoating to allow the finish.
I imagine a gelatin coating could be put on an alt processes print and
ferrotyped but I don't quite see the advantage of it. Supposedly one of the
virtues of Platinum, etc., is the absense of the gelatin and visibility of
the paper texture.
A sort of super wetting agent recommended for ferrotyping is still
available from Pa-Ko a maker of photofinishing equipment under the name
Pakosol.
---- Richard Knoppow Los Angeles,Ca. dickburk@ix.netcom.com
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