Group Purchase of Azide/Diazo Sensitizer - replacement for dichromate in carbon, etc.
A group buy is being organized to purchase an azide sensitizer (erroneously referred to diazo as well) for use in the carbon process.
We've been discussing this in depth on this thread (last several pages), but I thought I'd post a specific thread to get anybody who may have missed the other.
In case you're not familiar, azide and diazo sensitizers are non-toxic alternatives to potassium & ammonium dichromate. They are not carcinogens, are not environmental pollutants and have no shipping restrictions.
Moreover, they don't have a dark reaction and thus can be incorporated into carbon tissues from the outset and can be stored for extended periods of time. UltraStable Color Carbon Tissues were made with this very same sensitizer, and tissues that are 15+ years old still expose and etch within very acceptable limits.
I believe this stuff can revolutionize the carbon process. It will work on all protein-hardening based colloids (caesin, gelatin, etc.) but may not work for gum. Please refer to the experts on this point...
Anyways, if you're interested please PM me, post here or email me at my APUG username @ yahoo.com. This group buy represents a very significant savings over other suppliers and is the same stock that Tod Gangler uses to make his color carbon prints.
We're looking at somewhere between $180 to $200/kilogram, plus shipping. International should be OK.
FYI, they are used at a smaller percentage than the dichromates; somewhere around 0.6% if incorporated into the "glop".
Still working out the details, but so far the response has been great!