From: Sandy King (sanking@clemson.edu)
Date: 12/15/02-09:56:01 PM Z
Richard wrote:
>Quoting Sandy King <sanking@clemson.edu>:
>
>> How are you verifying the presence of iron hydroxide?
>
>Visually. Iron hydroxide causes a yellow-brown "stain".
>I compare the washed and dried sample against a clean
>piece of the same paper. This is done in sunlight.
>It may not show very small amounts of iron hydroxide,
>but there are probably other chemicals in the paper
>anyway.
>
>Richard
>---
>Richard Urmonas
>rurmonas@senet.com.au
>
>
>
Richard,
Thank you very much for sharing the results of your tests with us.
This is really good information to know and it contributes a lot to
understanding how to process VDB for better archival qualities.
I appear to be very fortunate in my working conditions with both VDB
and kallitype in that the tap water at my house is almost always
neutral or slightly acidic so that I rarely ever see any stain on the
paper and clearing is visually always 100%. I have been checking the
pH for a long time in my carbon work and it is curious that high
alkalinity is a problem with that process as well.
Regards,
Sandy King
This archive was generated by hypermail 2.1.5 : 01/31/03-09:31:25 AM Z CST