[pianotech] Board: trash or keep protocol

[David Ilvedson]

Bwwaaarrgggghhhhh?????   What the heck is that?   Let's talk about bearing/crown.   What are you looking at?
When I listen to an old piano and I hear good sustain and dynamic range, I think we have a good board.   But beyond that, what kind of crown...bearing is also helpful?

David Ilvedson, RPT
Pacifica, CA  94044

----- Original message ----------------------------------------
From: "Ron Nossaman" <rnossaman at cox.net>
To: pianotech at ptg.org
Received: 4/6/2009 8:38:54 PM
Subject: Re: [pianotech] Board: trash or keep protocol


>David Andersen wrote:
>> 1. Pluck strings in all sections of the piano; listen to bloom and 
>> sustain appropriate to each section. If it sounds good---if there's a 
>> definite increase in sound pressure and amplitude, a "bloom," within a 
>> second or so of the pluck in the tenor and treble (it takes longer after 
>> the pluck for the bloom to appear lower down in the piano) and then 
>> almost a coupling or strengthening of the fundamental tone and the first 
>> two partials as the tone decays---it is good. If not, and if there's any 
>> question or less than strong feeling, we replace the board.
>> 2. Measure bearing across bridges (if necessary.)
>> 3. Determine crown through the various methods talked about here ad 
>> infinitum (if necessary.)
>> 
>> The ears (and the bod they're attached to) are the first and the final 
>> arbiters of everything to do with pianos.
>> DA

>Disagree big time. Both crown and bearing will tell you 
>something about whether what you are hearing today is likely 
>to still be there tomorrow, or next year, so that's first. 
>Second is the sound, and that needs to be assessed at high 
>attack levels as well as plucking and blooming, particularly 
>in the killer octave. Listen for the Bwwaaarrgggghhhhh attack 
>distortion, and know that it will only get worse. Putting a 
>rebuild on top of a wonderful sounding (at pluck volume 
>levels) board that is on the ragged edge of crapping out 
>structurally isn't something you want to figure out after the 
>fact when you get *the call* next year. If it passes the 
>structure test, *then* if it passes the sound test, *then* 
>it's a go for keeping the board.

>Ron N