[CAUT] Riblets (was Gravalla Tension regulator)

[Ed Sutton]

Yep, these riblets can do magic.
I put two on a 1912 M with a weak spot in octave 5, and the sound came back.
They seem to work by adding a bit of stiffness to the board.
They can be tested with minimal damage to the piano, just a screw hole 
through the bottom of the soundboard and into the bridge.
Fandrich and Sons is now offering them for sale.
Ed Sutton


----- Original Message ----- 
From: "Barbara Richmond" <piano57 at insightbb.com>
To: "College and University Technicians" <caut at ptg.org>
Cc: "Pianotech" <pianotech at ptg.org>
Sent: Monday, September 24, 2007 8:38 AM
Subject: Re: [CAUT] Gravalla Tension regulator


>
> Hi Ric,
>
> Well, you might take a look at the August issue of the Journal and test 
> for weights or riblets on the soundboard.  Or have you already tried that 
> out?
>
> Remember that big 'ol Seiler grand I was wrassling with a couple years 
> years ago?  In October it's going to get at least one weight or riblet in 
> the 6th octave which is wimpy.  I tested by clamping my small Vise-Grips 
> on the bridge pins and the sound came right up.
>
> Barbara Richmond, RPT
> near Peoria, Illinois
>
>
> ----- Original Message ----- 
> From: <ricb at pianostemmer.no>
> To: <pianotech at ptg.org>
> Cc: <Caut at ptg.org>
> Sent: Monday, September 24, 2007 3:46 AM
> Subject: [CAUT] Gravalla Tension regulator
>
>
>> Sorry about the mispelling of the name... but I have a question I
>> need some advice on about this device.
>>
>> I was looking at how this thing was going to fit into a Hamburg C
>> this morning and found that the only placement that would allow for a
>> flush fit for both flanges would require that I remove a small 1 inch
>> wide piece of wood that runs from the joint between the rim and the
>> belly rail.  I suppose this thing is meant to have some small
>> stiffening affect... tho really its dimensions are so small I have to
>> wonder if it has any real affect.  That said... I am of course
>> hesitant to just yank it out of there.
>>
>> The other thing is that the belly rail on this Hamburg C looks
>> actually quite massive. And I am wondering if the tension device
>> would really be needed / make any real difference if installed.
>> Anyone have any relevant experience they would share with me ?.
>>
>> This piano is a nice sounding thing ... no killer octave problems or
>> the like... but I cant say it exactly sizzles with vibrancity
>> either... hence I thought it might be fun to try this.
>>
>> What say ye ?
>>
>> RicB