Maybe you could have just the hammers for the sharps be black... <G> On Sat, Oct 18, 2008 at 3:50 PM, <erwinspiano at aol.com> wrote: > > Fellow tone warrior. > Good to have another techno- splaination by some one that loves wool & > understands the nature of both ,in felt making,what an art, and hammer > making, also an art. The more we learn the more we can apply in our thinking > about hammers & voicing. > Andre referred to the hammer as a shock absorber but A hammer is > technically a non - linear felt spring. There's the bait now I'll see if > there are any bites. grin > Excellent post David S. > Dale Erwin > Take a sheep to lunch indeed. I was actually thinking about getting a > couple black ones and asking Jack to produce my own black > hammers....."Erwins Black velvets" built especially for the dark tone. > > > > Hi Dale > > Didn't catch the word "pre" when you mentioned pressing..., Just wanted to > make a positive point to the readership about coldish pressed hammers which > is that the tensioning of the felt is not lost as in a hot pressed hammers. > This tensioning of the fibers gives a kind of resiliency to the felt which > makes it very bouncy like a superball... remember them? The kind of heat > that most production hammers are made with erases this magical quality. I > believe that the special kind of tensioning found in lukewarm pressed > hammers contributes greatly to their beauty. > > The starting point for a heat level that starts to degrade the cold pressed > quality is a little "fuzzy". The quickest way to check is to steam a spare > hammer and if it expands at all, then it technically has density made by hot > pressing which greatly reduces resilience... The most resilient felt builds > density by intertangling (felting) of the fibers. It's a little confusing > because there are two ways of building density in a hammer, one by making > the felt dense enough before stretching around the molding then the > stretching itself builds density.... > > The buffing wheel felts are not hot pressed just hard by felting with very > high pressure... the fibers just ratchet together to a very high density... > amazing really... > > The amount of natural felting that occurs during felt production is very > critical. Too much and the felt will tear, too little and the tensioning > slips and the hammer is too soft... The art of producing a great cold > pressed hammer is really linked with the art of making great hammer felt. > > My hat is always gratefully off to Ray Negron and Jack Brand (and his > highly skilled feltmakers in Wurzen Germany). It would be a very different > world without you both! > > Best TY, > > David > > "Take a sheep to lunch" > > >David > >I agree. A loss of resilience occurs in Pre pressing, which is the > practice > >of pushing the felt into the caul before the underfelt is laid in,to > crease > >the felt in the middle. The purpose of this is so it is easier/possible > to > >center the underfelt all along the length of the felt strip in the >final > pressing. > >Pre-pressing or pres-stretching is more often over done & it is this > process > >where the felts ability to be tenisoned is reduced. I believe every >maker > pre-presses > >to one degree or another but pre pressing should be kept to a minimum, > just > >enough ot crease the felt slightly so the underfelt can stay centered with > the > >final press happens This is the the case with Ronsen hammers. > >Technically there are no Cold pressed hammers. There is always so heat > present > >to cure the glue. Something like 130 degrees when the felt is >pressed in > & then > >it's turned off. Ronsen hammers stay in the press 3 hours after the >heat > is turned > >off. Other hammer makers whiz them in & out of the press using far >more > heat to > >cure the glue faster. Of course this aids production but the hamners >are > losing resilince, >tension & compression under this protcol. I >think this > is the way buffing wheels are made. > >LOL > >Dale > > >>Dale, > > >>I've always felt (no pun intended) that tension in a cold pressed > >>hammer develops > >>resiliency and density at the same time and that this tension is >>always > diminished > >>by hot pressing. Imaging bouncing something off a stretched nylon > >>rope... (nylon > >>being very stretchy). If the rope isn't stretched tightly you can't > >>bounce off it > >>very well...? > > >>David S > > >>>Dale Wrote: <snip> Pressure is pressure but pre pressing removes > >>>resilience as does too much heat. <snip> > > ------------------------------ > McCain or Obama? Stay updated on coverage of the Presidential race while > you browse - Download Now!<http://pr.atwola.com/promoclk/100000075x1211139166x1200680084/aol?redir=http://toolbar.aol.com/elections/download.html?ncid=emlweusdown00000002> > -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20081018/a9b93f83/attachment.html
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