I did say that. David Love davidlovepianos@earthlink.net > [Original Message] > From: Farrell <mfarrel2@tampabay.rr.com> > To: Pianotech <pianotech@ptg.org> > Date: 2/28/2003 7:51:20 PM > Subject: Re: System Three Varnish > > "I was more wondering about the cosmetic quality." > > Geeezzzz. You shoulda said that before - now look what you have stirred up! ;-) > > Terry Farrell > > > ----- Original Message ----- > From: "David Love" <davidlovepianos@earthlink.net> > To: "Pianotech" <pianotech@ptg.org> > Sent: Friday, February 28, 2003 8:50 PM > Subject: Re: System Three Varnish > > > > > > I'm not sure why the flexibility of the varnish would matter. Either the > > board is stiff or it isn't. In the case of an epoxied board, the epoxy > > provides the stiffness and the varnish topcoat is not required to > > contribute additional stiffness. Nor would it make the epoxy any less > > stiff by virtue of its flexibility, if it is, in fact, flexible. I have > > used varnishes for years on soundboards, usually over a shellac undercoat > > without detriment. In this case, since I am stiffening the board with > > epoxy and System Three makes a varnish that supposedly does not have any > > compatibility with their epoxy. I was more wondering about the cosmetic > > quality. > > > > David Love > > davidlovepianos@earthlink.net > > > > > > > [Original Message] > > > From: gordon stelter <lclgcnp@yahoo.com> > > > To: Pianotech <pianotech@ptg.org> > > > Date: 2/28/2003 4:00:05 PM > > > Subject: Re: System Three Varnish > > > > > > > > > --- Delwin D Fandrich <pianobuilders@olynet.com> > > > wrote: > > > > > > > > OK. I bow to your far greater knowledge of chemistry > > > > and the history of > > > > varnish. I'm not a chemist--my response came from > > > > the answer to an inquiry I > > > > sent to one of the varnish-maker advertisers in > > > > WoodenBoat magazine some > > > > years back. But how do you reconcile all > > > > this with Jim Bryant's > > > > quote from Wilson Selby & Associates: > > > > > > > > <<"ABOUT SPAR VARNISH........ (strictly our opinion) > > > > Spar Varnish has been used for years to provide a > > > > super-hard, weather and > > > > water resistant coating for exterior wood. However, > > > > this extreme hardness is > > > > not suitable for most exterior wood surfaces on a > > > > home.">> > > > > > > > > Notice the reference to "super-hard." Not exactly a > > > > rubber sheet. And this > > > > tends to go along with my own experiences with > > > > modern "spar" varnish. Having > > > > once owned a large wooden boat I got lots and lots > > > > of experience with the > > > > stuff. Way more than I ever wanted. Sure seemed to > > > > dry hard. Could this be > > > > one of those descriptive names or terms that has > > > > changed with the times? Or > > > > is it now--the term--being misused by the > > > > manufacturers of the stuff? > > > > > > You just hit it on the head, Del! The description from > > > Wilson Delby and Associates, in typical contemporeary > > > laxity regarding the King's English, seems to be > > > confusing "Hardness" with "Toughness" which are not at > > > all the same things, at least in the normal jargon of > > > the finishing industry! > > > Hardness, of course, refers to the molecular > > > compaction of an element or compound. A diamond is > > > hard, although it's just carbon like soft graphite, > > > for this particular reason. This molecular compaction > > > allows the rapid transmission of shockwaves, i.e. > > > vibration, which is what I think we want in a sound > > > board finish. At the thicknesses applied, the hardest > > > of finishes will stll have plenty of flexiblity and > > > not impede the soundboard much. Of course, hardness > > > also means susceptibility to fracture along fault > > > lines, but this is not important in soundboards > > > because no responsible customer will be bouncing rocks > > > off it, anyway! Toughness, on the other hand, relies > > > on electrons in wide orbits, and susceptible to > > > exchange with neigboring atoms. It is essential for > > > elasticity, and why static electricty can be generated > > > by rubbing, well, rubber. You are actually rubbing the > > > electrons off. It is also this elasticity which makes > > > it absorb energy, i.e. vibrations, which is why we > > > don't want to use it, or anything like it, on > > > soundboards. But we do want to use it in high-abrasion > > > situations, such as cabinet finishes (to some > > > degree--elasticity of course impedes one's ability to > > > "rub-out" a finish") and woodwork on boats. > > > Come to think of it, by these criteria I believe > > > that the ideal soundboard finish would be CA glue, > > > which might also be able to, essentally, create a > > > "chemically-laminated" soundboard crown----- but I'd > > > sure hate to work in that factory! > > > > > > > > > Surely you will agreee that a rubber sheet > > > > glued > > > > > to a soundboard would be detrimental to > > > > conventionally > > > > > accepted notions of "good tone"? And that UV > > > > > resistance is hardly a factor we need concern > > > > > ourselves with, as a soundboard put in that much > > > > > direct sunlight would disintegrate far faster than > > > > its > > > > > finish would. ( And anyone who would treat a > > > > piano > > > > > like that would probably be tone deaf, anyway! ) > > > > > > > > While I have never tried coating a soundboard with a > > > > rubber sheet, I have > > > > directly compared a number of soundboard finishes > > > > In no > > > > case were we able to attribute any tonal change to > > > > the soundboard finish > > > > until the coating thickness became a significant > > > > percentage of the overall > > > > thickness and/or the coating mass became a > > > > significant percentage of the > > > > overall soundboard assembly mass. That occurred with > > > > four of five coats of > > > > epoxy and with the polyester (I don't remember the > > > > coating thickness). > > > > > > > > And, unfortunately, I have encountered altogether > > > > too many piano which have > > > > had their soundboards exposed to eiter direct or > > > > indirect sunlight during > > > > some part of the day. This being the case, and > > > > knowing how epoxy does break > > > > down fairly rapidly when exposed to UV light, I > > > > still recommend covering any > > > > coating epoxies applied to soundboards per my PT > > > > Journal article with > > > > another finish material containing UV blockers. > > > > > > > > Del > > > > > > Makes sense, Del, but I'd make this top coat as hard a > > > one ( not "tough" ) as I could find! > > > > > > Thank you for the discourse. > > > Respectfully, > > > Gordon > > > > > > > > _______________________________________________ > > > > pianotech list info: > > > https://www.moypiano.com/resources/#archives > > > > > > > > > __________________________________________________ > > > Do you Yahoo!? > > > Yahoo! Tax Center - forms, calculators, tips, more > > > http://taxes.yahoo.com/ > > > _______________________________________________ > > > pianotech list info: https://www.moypiano.com/resources/#archives > > > > > > > > _______________________________________________ > > pianotech list info: https://www.moypiano.com/resources/#archives > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives
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