GALLIC ACID as a developing agent?!

[ruilourosa]

can i use Gallic acid in any modern developer with interesting properties? is it soluble in tea or glycols? does it tan the emulsion?

any advice?

 

[largeformat pat]

Gallic acid heat changes to Gallol. Or the full term is Pyorgallol. Talbot used Gallic acid to develop his paper negatives. It is stated that the action was slow and weak. "The Book of Pyro and the PMK formula" I now this doesn't answer your question directly. However, I guess it's a start.
Pat

 

[ruilourosa]

i already made calotypes but i wonder why this developing agent isn´t used in modern black and white formulae!

 

[largeformat pat]

Heated, Pyrogallol is used normally with another agent say Metol and sodium Bisulpfite. this forms one part of a Pyro developer. It was very popular up until the mid 60's. There are still some of us who use pyro based film developers.
Pat

 

[ruilourosa]

yes i also use wd2d+, pmk, and some triethanolamine based tanning developers with pyrogallol and pyrocatechin or hidroquinone, i wanna know about Gallic acid!

 

[Nicholas Lindan]

It was very popular up until the mid 60's.

1860's or 1960's? [insert smiley as needed]

 

[Alan Johnson]

http://books.google.co.uk/books?id=...=20#v=onepage&q=gallic acid developer&f=false
It may be that the early processes involved physical development and some silver nitrate might be needed to get it to work.

 

[removed account4]

yes i also use wd2d+, pmk, and some triethanolamine based tanning developers with pyrogallol and pyrocatechin or hidroquinone, i wanna know about Gallic acid!

isn't gallic acid the same as pyrogallol ? it has just been warmed ?
if so, you have been using it all along without realizing it ...


btw -
do you have any examples of your callotypes + salt prints ?
how long were you able to keep your silver nitrated / iodized paper before it went bad ?

john

 

[Ian Grant]

No Gallic acid is Tri-hydroxybenzoate while Pyrogallol/Pyrogallic acid is Tri-hydroxybenzene, two different compounds, but it was used before Pyrogallol in early photography.

Ian

 

[Donmck]

Gallic acid is(was )the preferred developer for albumen glass plates.

I believe the formula is 6 grains of gallic acid per ounce of (clear rain)water.
If it hasn't rained in a while you could sub distilled.

my average times were 30-45 minutes per plate.If the neg is still thin after 45 min.,you can intensify with a few "minims" of a 10% solution of silver nitrate.

Not the preferred developer for anyone with any type of time constraints.

Don