White gloves

Joe Iraci <joe_iraci<-a t->pch< . >gc< . >ca> writes

>The study which Doug Nishimura referred to in his April 22 message
>was performed in 1992 by Rudiger Krall from Germany and the late Dr.
>Klaus Hendriks.  The work involved examining the literature to
>determine the composition of sweat which is the major component of
>fingerprints. Subsequently, artificial sweat solutions were made and
>applied to a range of photographic materials from salted paper
>prints to contemporary silver gelatin prints.  The samples were aged
>at 60 degrees C and 75% RH for up to 30 days.  It was determined
>that sodium chloride was the most active ingredient in sweat that
>can lead to staining.

Didn't know that Joe was on this list. I was going to call him for
more information about the study since I was dredging up vague bits
of information from a badly failing memory. Joe is right about the
salt. When skiing in the winter my face tends to get gritty with
salt. Anyway, the effect can be a problem and relatively rapid. I
neglected to mention that non-stainless steel or corrosion resistant
titanium (don't know if all eyeglass titanium alloys are corrosion
resistant) are eaten at the temples down to wires. I also ate
through the back of a watch (non-stainless) in less than a year.

Polaroid apparently has a synthetic sweat formula that they've used.
They used to use an employee with aggressive skin, but he stopped
working (as a corrosive test) when he started taking an
anti-hypertensive. (Just goes to show how much things in the body
can affect sweat.)

One note to add to Beth Richwine's about nitrile gloves. They are
degraded quite rapidly by ketones (like acetone).

-Doug

                                  ***
                  Conservation DistList Instance 10:94
                  Distributed: Tuesday, April 29, 1997
                       Message Id: cdl-10-94-005
                                  ***