Hi,

I just wanted to respond to the statement made today in this thread that, "
acetone can erode metal over time."

As an objects conservator who specialized in metals and arms for over 11
years I have not encountered any empirical of scientific evidence or literature
that supports that statement. Acetone in an organic solvent widely used in
conservation and in industrial cleaning with numerous applications in metals. I
have not read of any significant ionic interaction with metals nor of residue
problems with acetone - since it is one of the more volatile solvents that we use
(meaning almost all of it evaporates into the air). Metal erosion occurs when
metals are exposed to a stream or flow of a liquid that strips metal ions and
can cause significant metal loss - metal plumbing in old houses is a good
example or the use of certain industrial acids or caustics can cause this in
factories and pipelines. Since B-72 is a metacrylate copolymer that is dissolved
in a solvent such as acetone, once the acetone quickly volatilizes and the
resin hardens there are only slight trace amounts of acetone left and they are
bound up in the resin - and they hardly constitute a stream or flow of liquid.

Most of the chemical damages that I have witnessed on metals in collections
come from exposure to sulfur compounds (e.g., silverware bound together with
rubber bands), or chloride compounds (e.g., metals stored with PVC plastics),
old polish residues, and my personal favorite - the human fingerprints etched
into the metal surfaces.

So I think I can safely go out on a limb here to state that I would heartily
recommend that you can safely use your B-72 on metals with no worry that you
are eroding it.

Cheers!
Dave

David Harvey
Conservator
Los Angeles, California, USA

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