Jeffrey D. Mathias (jeffrey.d.mathias@worldnet.att.net)
Thu, 29 Jul 1999 22:50:14 -0400
Eric Neilsen wrote:
> ... it does
> take some time for paper to adjust to changes in RH. The wet paper would
> have a hard time getting to an RH of 65%, with out first becoming drier
> (less RH) than ambient conditions. ...
Several things:
A) I humidify the paper prior to coating. It is almost limp and with no
"snap" as when it is bent. So there is plenty of moister in the paper.
B) I have stated before that I do not have any way of measuring the
humidity in the coating or the paper. I do use a procedure that is very
consistent and reproducible which I believe to be the important aspect.
The paper consistently gets to a consistent RH, although I can only
guess what that RH may be. But most likely I feel it is close to
ambient. For "dry" the same, I only know it is heat dried to the most
crispy state I can get it (without charring it.)
C) The point of this test was to compare "wet" and "dry" exposures to
identify any general differences and that it did. The "wet" was indeed
moist, and the "dry" was snappy, crinkley dry. Knowing the exact RH
will in all probability not provide much usefulness.
D) I've found that letting the coating sit around before exposing does
more harm than good.
Carl Weese wrote:
> I think we'll need to see if the 82 degree
> temperature is having a big effect, as I suspect it might.
I suspect it might as well. Although I have only detected and
documented temperature susceptibility with POP, not with DOP. But that
could only mean that I haven't noticed the effect yet or have and not
pinned it to temperature.
I will be repeating this test when one of three things happens.
Rosemary finally lets me buy an air conditioner (yea, after we finish
all the house renovation, including her office); City of Tampa pays me
the balance they owe me from last August for some prints; the cool
weather gets here. I've got humidity control, heating, heat exchanger
ventilation system, but no cooling yet. Who'd think it'd stay so hot so
long here in New England. And I never noticed (or recognized) problems
due to temperatures less than 100F until I did POP. I have never
studied solarization either since I never had a problem with it.
-- Jeffrey D. Mathias http://home.att.net/~jeffrey.d.mathias/
This archive was generated by hypermail 2.0b3 on Thu Oct 28 1999 - 21:40:38