Re: Acceptable Chemical Grades For Alt?

>>>As for what "Polaroid" or anyone else advises -- how often have you used
canned food after the "sell by" date and found it perfectly fine? This
doesn't hold for, say, dairy products, or others that need refrigeration,
and doesn't mean "bad" chemicals can't be shipped (I've had some from
companies I won't mention here, including Kodak). But if the *color* of
the chemical is what it's supposed to be (pot ferricyanide should NOt be
full of big yellow lumps, for instance), odds are 100 to 1 it's good --
for alt.>>>

I think Polaroid’s knowledge, advice, and recommendations are what I need to pay attention to, judy. The question was about reagent grade, lab, photo, other grades of chemicals and not canned food.

In the case of the Vectograph process, purity is not always an issue. I most certainly know far more about making Vectographs than anyone on this list. I am, in fact, probably the only practitioner of the process outside of one or perhaps two companies.

As for bad chemicals being shipped, this often depends upon the company selling the product. I can name a few companies that manufacturer ultra pure chemicals (costly) and this does not happen. I can see it happening if you deal with sellers of products they repackage. In this case, you can never be sure about purity.

Bob
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Received on Fri Oct 21 19:32:43 2005