From: Art Reblitz
To: "'Mechanical Music Digest'
Date: Tue, 14 Jun 2011 09:49:22 -0600

Subject: Coating Protects Against Valve Seat Corrosion

Corrosion on valve seats is becoming more of a problem than it was 20 years ago, possibly because today's valve leather has more acid in it than previously.

Two years ago, I clamped samples of split suede cowhide, pigskin, vegetable-tanned cowhide, white CPL, tan pouch leather, and maroon kangaroo leather to a sheet of unlacquered brass. Now, two years later, verdigris is forming under every sample, refuting the idea that any of these types of leather are immune to causing corrosion.

I didn't even try a sample of alum-tanned sheepskin because that has been known to have a devastating effect on metal ever since I entered this business in the 1960s.

G.J. Nikolas & Co., Inc., nearby Chicago in Bellwood, Illinois, has been making industrial quality metal lacquer since 1890. Their product brochure states "We were the first to develop air-dry lacquers for use on automobile production lines, and premiered this invention at the 1911 World's Fair." Customers have included Otis (brass elevator panels), Lyon & Healy (harps), and many band instrument and lighting product manufacturers. We have used small quantities of Nikolas #2105 clear lacquer on valve seats and other metal parts for about 30 years with enduring excellent results.

I spoke with the owner of Nikolas a few years ago, and he said their #2105 clear aerosol lacquer continues to be their best product for this use. If you need only a small quantity for several pianos, you can purchase individual cans from Votaw Tool Co., a supplier of band instrument repair tools and supplies ( http://www.votawtool.com ). Nikolas' minimum order is a case of six cans. Please don't bother Nikolas for smaller orders, but if you need one or more cases, the web site is http://www.finish1.com/splash.htm

I'm interested to learn about others' experiences -- both good and bad -- with ways of preventing leather-caused corrosion.