Re: Do dichromates change with age?
http://www.colourchromes.com/potassium_dichromate.htm This page says: "...It is non-caking and if stored in a cool, dry place away from heat, shelf life is indefinite..." Another thing to consider would be contamination... Regards, Loris. 14 Temmuz 2008, Pazartesi, 4:44 pm tarihinde, Loris Medici yazmış: > 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.? > > Regards, > Loris. > > > 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
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