To my knowledge-and I think I've tested just about all of them or know other folks or organizations who have-there is no practical wood finish in common use that provides a significantly better barrier to water vapor than any other. Assuming they are all applied properly and in accordance with their manufacturer's instructions none of them-including varnish in its many variations-stands out as clearly superior. Nor, for that matter, do any of them stand out as being particularly worse than any of the others. Except, of course, for shellac which provides neither a particularly good moisture barrier or vapor barrier. Some varnish formulations have better moisture resistance than do some nitrocellulose lacquer formulations but note that a moisture barrier is not the same as a vapor barrier; if we are expecting a wood finish to enhance tuning stability it would have to be a superior vapor barrier. ddf Delwin D Fandrich Piano Design & Fabrication 620 South Tower Avenue Centralia, Washington 98531 USA del at fandrichpiano.com ddfandrich at gmail.com Phone 360.736.7563 From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Brent Fischer Sent: Tuesday, February 15, 2011 8:44 PM To: caut at ptg.org Subject: Re: [CAUT] Steinway rebuilds Ron, The research I mentioned was pertaining to permeability issues , sorry that wasn't clearly stated. The reports that you claim about increases in stability are probably design related not finish differences, and are just as speculative as me saying lacquered boards need double duty damp-chasers. If I indeed implied that varnish is a determining stability factor, well, I'll back the truck up on that one. The real question I have is if you know that varnish provides a better moisture barrier in the first place, why use a coating with less moisture sealing properties? Because it's easier? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20110216/e24b7c38/attachment.htm>
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