From: John Glen (microcrystals2002@yahoo.com)
Date: 02/22/03-06:18:52 AM Z
Hi guys, Ryuji...
What are you talking about here?
Maybe I am miss reading something, but what is it with
this NOT "gelated" at a low temperature." typically,
Gelatin will "gelate" (gel or set) at room
temperature, or upon slight cooling. Results from this
relativly high temperature setting as when it is
simply allowed to dry in a warm room, are quite
adequate, particulary ordinary thin layers on
papers.(trouble may be encountered with excessivly
thick layers in hot weather when a "crust" could
concievably form, and "protect" the gelatin underneath
from drying)
Commercially, with large amounts to coat, the coating
speed is rather fast and cooling (quick setting) is
essential... in such cases the exact temperature mmay
indeed affect dry "Scratch Strength" or what have you,
but IMHO the small scale experimenter has nothing to
fear... the results will be OK.
In any case the gelatin solution will "gel" without a
specfic low temperature "setting" period. In fact I
doubt that a gelatin solution can be dried without it
setting... (well I guess if you drove off all the
moisture you could... but that in itself would be
abnormal! not something you are likely to choose to
do.)
On the otherhand, if you are talking about the special
non-gelling gelatins, well... I hope you are not.
Since Philippe answered your question, perhaps he
understads what you mean. I may still be a little
confused.
> I guess dry plates produced without gelation process
> may be usable,
> but I'm still thinking about getting a refrigerator
> for gelation
> process.
You won't be doing it without setting the emulsion, if
I understand you correctly... you just won't be doing
it at a particulary low temperature... most likely,
you will be doing it at night (wild guess)when the
temperature will be a bit cooler anyway.
A refrigerator is a cool idea though. What are you
going to make? If it's glass plates, What will your
setting/drying temp be? Unless it is pretty high, I
would worry more about the price of the glass. For now
anyway.
Oh, and while I am here, s.o. asked if you or some one
could use denatured alcohol, for glass plates... well,
it depends on the reason, but in general, yes,
denatured alcohol is usually ok, I belive it is usully
denatured with methanol or perhaps phenol, and in
either of these two cases it should be fine. (Don't
Drink / Don't Breathe);-)
Just be sure to check what the additive is.
J.G. (Ray)
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