Peter Charles Fredrick (pete@fotem.demon.co.uk)
Sat, 02 Oct 1999 17:08:41 +0000
Hi Nick,
>>A 5N (normal) NaOH is 200g/liter sodium hydroxide. A 50% solution is
500g/liter. Provided that it is kept sealed, there should be no problem
using this solution more or les indefinietly. Wear gloves and eye
protection, lab coat if you have it. As NaOH solutions go, a 5N isn't that
nasty or odorous but can cause skin burns.
Jonathan Lee
-----Original Message-----
From: Nick Makris [mailto:nick@mcn.org]
Sent: Saturday, October 02, 1999 12:16 PM
To: Alt Photo
Subject: RC negatives - stripping paper
Hello again,
Not so long ago, I read a post from Peter Fredrick regarding the removal of
the emulsion from the paper backing of RC prints. While I have successfully
accomplished this at times previous, he went one step further by suggesting
the use of Sodium Hydroxide at 50% to further clear the paper.
Not being very chemically minded, I have a question(s) regarding the
strength/safety aspects of the material I have on hand. I found a plastic
pint bottle of liquid Sod Hyd in a cupboard in my darkroom - has always been
in the dark. It is heretofore unopened and was manufactured in 1980. The
strength is declared at 5.000 Normal.
If you would be so kind, I would like to know, 1) if this is the same stuff
that was recommended and is the shelf life ok? 2) use it at what dilution?
3) besides gloves, what other safety precautions should I take??? This the
only chemical that I have that talks about severe burns on the label,
however, it says nothing about ventilation. I will appreciate your
comments.
Many thanks,
Nick<<
Many thank Jonathan for answering this message, this not a product that I
have personally used but no doubt it works fine, if one follows your
sensible instructions.
I used Domestos which is a Brit household bleach, at 50% percent, Which I
have been told by chemist friends is equivalent to sod hydroxide.Please
don't forget to laminate the front of the print or no print !, and be
careful caustic means chemical burning.
Pete
http://www.fotem.demon.co.uk/ To visit petes parlour gallery, there is now a
Guestbook !
This archive was generated by hypermail 2.0b3 on Fri Nov 05 1999 - 21:26:26