View Full Version : How test if chemical are good?

22-Jul-2015, 12:40
I have the kit below and am wondering how to test if the pyro and dichromate (sp) are still good. They are OLD. Like late 80s or early 90s. I want the Dichromate for carbon printing and no idea what I would use the pyro for.


22-Jul-2015, 14:02
The dichromate is nearly guaranteed to be just fine. I suppose the Pyro too if it's the dry powder. You can test the dichromate by just using it. Same with the Pyro.

22-Jul-2015, 16:15
Can I mix a tiny amount of dichromate in some water and see if it turns color?

sun of sand
22-Jul-2015, 22:50
Its still good

22-Jul-2015, 23:24
Can I mix a tiny amount of dichromate in some water and see if it turns color?

Yes it will and it will be good.

23-Jul-2015, 00:46
Well, Steve's rule is; "If in doubt, try it out"... But you should get it out of those bottles, and into better containers... (I had some chems from PF long ago in those juice bottles, and not everything lasted as well as in a good glass or poly container...) If it's been in a dark, dry place all this time, all the better...

The pyro might be questionable... (the last time I used some very old pyro, (but in glass) it was discolored and rapidly oxidized in solution, left a blotchy stain on film, and made a hard to clean "bloody" mess anywhere it dripped...) Maybe you missed a bullet, but....

Steve K

23-Jul-2015, 00:52
I am using metol from Kodak and hidroquinone from May and Baker from the 70īs, dichromate should be fine and if properly capped so is pyro, the only thing that usually getīs ruined is glycin.