theese are the 2ml/50ml glop wedges, 2ml=~0.69g diazo, I made a mistake there. The 20minute 4ml/50ml wedge is very similar to #3 wedge above, slightly paler. I want to try printing with a lower concentration of diazo in the tissue when I get a chance to make more.
It needs more exposure to get the black I get through pictorico with 8min and 2%AD. I will try my last strip of 0.69g/50ml glop with a 35 min exposure and see. Dmax is no problem with colour like Tod Gangler or multiple transfer like Gordon Chapple, to me it seems a small price to pay for the health and environmental benefits, multiple transfers open a whole new world of creative possibility so it may actually be an advantage.
It transfers very easily and I have had no problems really.
I didnt get the MSDS and have no idea what is in the sensitiser, but my gut feeling is that all of their granular sensitisers are the same and the number is used to refer to different weights of diazo, they must be using diazo concentration to control contrast, so different numbers probably only refer to different diazo concentrations in the final mixed emulsion. I could be wrong though.
ok 35 min gets me another stop but still not a black. the good news is that it seems to still react fairly linearly with a stop of exposure giving a stop on the wedge, there is really only a stop and a bit left before I run out of stepwedge. I will scan the wedge when it is dry.
The bad news is that the kiwo ulano screen printing agents here in NZ are unable to supply me with the sensitiser on its own, I even gave them links to my carbon prints and others on unblinkingeye and colourcarbonprint.com and Sandy Kings article and Tod Ganglers videos so they know what I am up to.
The effort you guys are putting into finding non-toxic alternatives to dichromate is important. Not being a chemist, I had to search blindly (otherwise known as trial and error) for quite a while until I found something that worked. Unfortunately, the factory that manufactured the sensitizer blew up several years ago. Here's their product info:
So thats why they wont sell me a kg of the stuff! Thank you.
Anyway 60 minutes darkens things up substantially but only gets me 1 step extra, I reach paper white, or in this case yellow, on step 18. Tissue is all finished now. compared to the same tissue spirit sensitised with 2%AD its about 3 stops or more slower.
Fairmount Chemical Company still exists, anyone care to ring them?
I'm not so sure...I can't find a company website. There doesn't seem to be any real information about them on the 'net, and I found one note that mentioned an involuntary Chapter 7 bankruptcy filing (asset liquidation) some time in 2007.
Originally Posted by mdm
Thanks for posting the data sheet, CMB. Seems you found a chemical what worked pretty well...
Contact details here http://aidchemical.com/commerce/info/contactinfo.jsp
If we can get someone, perhaps Artcraft to stock it, that would be perfect.
It is quite clear to me why the plant blew up! ;)
Good luck, but my advice is to be careful, be very very careful!
If it is a threat to safety then its a no go, however screen printers have small amounts of sensitiser shipped to them routinely, with no problems, so it may be workable.
This is an azide or N3 compound. Beware of all azides. They are usable but very touchy. I don't like to handle them at all.
You're the expert. Thanks for your contribution. Perhaps there is another alternative? If screen printing sensitiser works ok, then it may be better, just a matter of finding a scource.