U of S | Mailing List Archive | alt-photo-process-l | Re: Do dichromates change with age?

Re: Do dichromates change with age?

Hello Sam,

A question: does your unit have a light integrator? If yes, by saying
"longer exposure time" you mean "more units" right? If not (more units),
then could it be that your lightsource is getting weaker somehow (either
due bulb wear and/or voltage fluctuations)... Have you absolutely ruled
out probable problems about electricity / integrator / bulb ect.?


14 Temmuz 2008, Pazartesi, 4:30 pm tarihinde, sam wang yazmış:
> Has anyone come across any data about whether dichromates losing
> speed, or effectiveness?
> My jar of ammonium dichromate is probably over 20 years old (yeah, I
> use very small quantity in gum printing) and it appears to suddenly
> need longer exposure time. Doesn't make sense, especially since I'm
> using an Amergraph printer for exposure. Humidity and everything else
> has been kept fairly consistent.
> Anyone else has similar experience?
> Sam