Shellac vs. lacquer

[David Ilvedson]

All this talk about shellac, lacquer etc. and I remember a American tech who lived in Copenhagen talking about collodian and ether.  I know RicB also talked about it.  I don't think collodian is available in the states?  Couldn't lacquer thinner be used instead of ether...scary!  I would like to try collodian...in a hammer that is.

David I.



----- Original message ---------------------------------------->
From: Bill Ballard <yardbird@pop.vermontel.net>
To: <pianotech@ptg.org>
Received: Tue, 16 Jul 2002 07:36:08 -0400
Subject: Re: Shellac vs. lacquer

>At 2:37 PM +0200 7/15/02, Richard Brekne wrote:
>>Holy Christmas Bill... you used at least eight 67 cent words
>>there... :) gets complicated for this Norwegianized mind of
>>mine.

>They cost me at least $4.95 apiece. You'll see a noticeable mark-up
>in the invoices I'm sending out. The big challenge to the internet
>economy is creating revenue streams out of all this digital traffic.

>>If you want an idea of how Shellack is going to behave over
>>time inside the hammer take a thick dense strip of felt (for
>>example damper lift felt for the back end of grand keys) and
>>soak a short strip of it in Shellack and let dry. The have
>>fun playing around with it in as many creative ways as you
>>can think of and check out how it reacts.

>At 10:45 AM -0700 7/15/02, Susan Kline wrote:
>>Now if you want the real gritty about what the stuff does to felt
>>fibers, why don't you take a scrap hammer, soak it well in shellac,
>>dry it out, vise it to something sturdy with the felt aiming
>>upwards, and whack it with a mallet a bunch of times? Then take your
>>knife, cut it open, and put thin slices on a microscope slide?

>Sounds like the test for ductility of music wire. I was contemplating
>something on the single fiber scale, and which would compare resins.

>>As for whether this whole process leaves the elasticity
>>decimated or not I dont know.... try stretching the strip
>>above and see how snappy it is ! Tho I have to wonder if
>>your segmentation would like reaaaly be synomonous with
>>chopping the felt fibers into a million short peices with
>>one of those Japanese knife thingys. :)

>I should clarify. The elasticity I'd like to witness is that of the
>resin by itself. Heck you could make a reinforcer out of watered-down
>TiteBond. Its elasticity would be greater than keytop plastic. For me
>what distinguishes these resins (lac bug stools, nitro lacquer,
>shellac and keytop plastic) in their results is their springiness.
>(Oh, cure time is also a major consideration, but in the scheduling
>of the work, not necessarily in tone quality.)

>I seriously doubt there is any chemical reaction between the felt
>fiber and and the resins which would degrade the fiber (and
>specifically, its elasticity). The behavior of the combination i
>would bet is entirely a mechanical matter.

>Under a powerful microscope, coat a single fiber. The fiber's
>springiness is a known factor. The resin coating stiffens the fiber,
>making it slower to bend under a deforming force (ie. collision with
>taut music wire). But there's a big difference in how that fiber will
>return from the deformation, based on the elasticity of the resin.
>I'd like the resin with the greatest elasticity. Any coating can
>stiffen the fiber, I'm looking for one which will contribute some of
>its own elasticity to the fiber, after reducing the fiber's
>elasticity.

>Yes the breakdown is a significant determinant in the long-term
>prospects for sound. Thanks to Richard for bringing this up. Imagine
>the resin coating as a sheath. Its brittleness/elasticity will
>determine how its will survive the flexing which occurs with each
>hammer strike. (Certainly that flexing is likely to exceed the
>elastic limits of the resin mainly at the strike point.) The
>segmentation I was exploring happens when the flexing overcomes the
>resin's limits. At that point, wouldn't the coating have fractured
>into segments. And now, coating the fiber not as a single sheath but
>in many short segments, wouldn't it it have lost the original
>stiffness it had as an integral whole sheath? Would its effect on the
>fiber now mainly be limited to its mass, now clinging on to the fiber
>i separate chunks?

>This is what pricked up my ears when Richard talked about the warming
>of the sound as resin breaks down. I'm actually looking forward to
>this process with shellac, because I haven't noticed it with keytop
>plastic.

>At 10:45 AM -0700 7/15/02, Susan Kline wrote:
>>P.S. A blow-by-blow of your return visit to voice that set of
>>hammers would be very welcome! I've used shellac for voicing, but
>>never for building up a new set of hammers from scratch before.

>I will probably do the report tomorrow night. Tuesday is one of three
>nights per week during the summer when I have two concert running, 45
>minutes drive apart.

>Briefly, this is a D with the whole nine yards done last year (I did
>a new action with complete Stanwood), sitting in a concert shed
>(http://www.svac.org/2002_final/wed.html), with a theater stage and
>proscenium. I didn't push the reinforcing too hard last season, as
>I'm a firm believer in the "work-hardening" of the strike point. But
>the time hard come to make the piano project. So from that
>standpoint, the shellacing is part of the initial set-up. I got over
>there yesterday and found the piano much as I remembered it from the
>week before (and anticipated finding it). So 1.5 hours of loud
>voicing (with Zen Reinhardt's "racket-ball"), mezzo, then U.C., and
>finally quiet voicing. The piano is no ready for the opinions of
>others.

>Bill Ballard RPT
>NH Chapter, P.T.G.

>"I gotta go ta woik...."
>     ...........Ian Shoales, Duck's Breath Mystery Theater
>+++++++++++++++++++++