[pianotech] Pinblock expensive experiment

[George F Emerson]

Hybrid blocks are not balanced panels, and guaranteed to bow, twist, or 
whatever.  Not that it matters, being secured to a cast iron plate.  If it 
were a component of a totally wooden structure, a balanced panel would be 
very important, the ply thicknesses, species, and grain orientations being 
symmetrical about a center ply.  This would be an absolute requirement in 
most wood structures, but not so much in pinblocks, where the cast iron 
provides the required structural integrity.  Fit it, clamp it, screw it to 
the plate, and don't worry about it.

Frank Emerson

----- Original Message ----- 
From: "Ron Nossaman" <rnossaman at cox.net>
To: <pianotech at ptg.org>
Sent: Sunday, April 04, 2010 6:52 PM
Subject: Re: [pianotech] Pinblock expensive experiment


> Duane McGuire wrote:
>> But rather than just reacting to my own self-pity, I'd appreciate your 
>> input, before my wallet gets even thinner.   In the category of self 
>> recrimination, I expect that I should have measured the bow in that 
>> multi-lam and shipped it back when I found the degree of deflection that 
>> was present.
>>
>> Thoughts?
>
> In 35 or whatever years in business, I've never sent back a warped block. 
> They're a nuisance to fit, but I never had one that wouldn't screw down - 
> or up - to the plate. 10mm! That's a fair bend. First, I'd see what it 
> took to clamp it to the plate. Once it's cut out, it'll be narrower and 
> easier to conform. Then, if I was still worried about it, I'd slice it 
> down the middle and re-glue it with either epoxy or Unibond 800. In any 
> case, wood is more flexible than cast iron, and will conform. I really 
> don't think you're in as much trouble as you think.
> Ron N