Coating brass mounts (from ListServe)

Hello,

What are people's thoughts and knowledge about the need to coat brass mounts. For our last exhibit we decided to leave all our brass mounts their natural brass color rather than painting them with acrylics. There was no direct contact between the mount and the artifacts. We always use a barrier of either Polyolefin tubing, felt or Volara. However, some people have expressed the concern that the mounts should still have at least been sealed with a clear coat of something like B-72. Our thought had been that the reason we were using brass is for its high corrosion resistance and besides it darkening slightly from when it was first made it would pose no threat to the artifact.

We would like to continue to not have to paint the mounts if possible.
Any light on the subject would be helpful.

Thank you,
Ben

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Hi Ben,

I like the natural brass sometimes, too, if the mount won't be out for a
long, long time. Keep in mind, though, that if there is an electron
transfer between the solder and the brass, you'll get an ugly fluffy
growth on the surface of your mount. That will happen faster in cases
with artifacts that have been in the ground or under the ocean, or if
there is any moisture in the air around the mount. Essentially --
moisture and salt, which act as an electrolyte will help this process
along.

I have had good results using B-72 to retard any salt and/or moisture
from reaching solder joints. If you can manage to remove any roughness
or pitting on the surface of the metals, you will be able to get a
pretty good seal. You won't have to coat the entire mount, either, if
you want to allow the surface of the brass to patina naturally. An
all-over coating of B-72, however, will keep your mount looking like new
brass for a long time.

I hope that helps.

Steven Short
Associate Preparator
Portland Art Museum
1214 SW Park Ave
Portland Oregon, 97205
503.276.4269

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I could be wrong, but I have been told that the ugly fluff that grows out of solder seams is actually pickle residue that is trapped inside microscopic pores in your solder seam. If you use a pickling acid, You should always neutralize with baking soda in water once all fabrication is complete. err on the side of caution, let it soak for a day if you can.

I have used Renaissance Wax as a clear coat. Its Archival, and it smells good.

Personally, I am all for leaving mounts brass. In a lot of cases, I think it looks much better than trying to cheat the eye with acrylic paints. I have even patinated brass mounts before to help minimize their visual presence. Again i emphasize the importance of neutralizing with baking soda and water. If only I could convince more curators to let me do it....

Michael Studebaker