Manganesed Phospholene #7

Lara Kaplan <larakaplan [at] hotmail__com> writes

>I am examining and treating a group of archaeological metals treated
>in the 1960's with the rust remover and corrosion inhibitor
>Manganesed Phospholene #7 (Western Reserve Laboratories, Cleveland
>OH), a proprietary product that saw some use in the past and is
>still manufactured and used today. Some of the artifacts in the
>group have remained stable, however others are corroding. With the
>awareness that there are many factors at work such as surface
>coatings, changing environmental conditions, etc., it would still be
>helpful to know more about the mechanisms of this product to better
>understand its effects. Has anyone researched or used this product,
>or encountered collections on which it was used?

Manganese Phospholene #7 is a phosphoric acid-based cleaner, strong
in acid and with some solvent and/or surfactant added.  It will
clean rust and other corrosion products from many metals, but will
not leave a robustly corrosion-protected surface.  As Lara Kaplan
recognizes, a variety of factors come in to play in determining
which clean metal rusts first.  To keep clean active metals from
corroding requires either keeping the item in a controlled
environment or using an appropriate corrosion inhibitor in oil or
wax.

Patrick Gallagher
Materials Preservation


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                  Conservation DistList Instance 16:76
                   Distributed: Friday, May 30, 2003
                       Message Id: cdl-16-76-003
                                  ***