[pianotech] YC Capo Bars

[Scott Jackson]

Can you harden Zinc alloy?

Scott Jackson


On 20/09/10 07:10, Roger Gable wrote:
> Jon,
> I suggest an alternate repair. Reshape the original insert and have 
> the machinist who is working with you check the hardness at the crown. 
> It should be around Rockwell 40. If not, explore having it hardened. 
> It could end up costing less to harden the insert rather than machine 
> a slot. Also, the water hardened drill rod you obtained from your 
> local supplier is probably too hard and may cause buzzing at the 
> duplex. Additionally, I've always felt that the capo should have as 
> few mechanical "interruptions" as possible.
>
>
>> A post last month showed the string impressions in the v-bar insert
>> on a 1996 Weber grand.
>> http://ptg.org/pipermail/pianotech.php/2010-August/027631.html
> John,
>
> That looks like the Zinc alloy inserts that were used for a short time in
> about 1994 or so.  They not only were too soft, they made the piano very
> hard to tune! Very sticky material with steel wire pressing against it.
>
> They later changed them to brass, which tuned a lot smoother but tended to
> make the tone more zingy, and create more duplex noise because the angle
> through the capo area was fairly shallow.
>
> I agree with your solution to use brass rod, but you might want to increase
> the counter-bearing angle a little while you're at it.
>
> Don Mannino
>
> -----Original Message-----
> From:pianotech-bounces at ptg.org  <http://ptg.org/mailman/listinfo/pianotech>  [mailto:pianotech-bounces at ptg.org  <http://ptg.org/mailman/listinfo/pianotech>] On Behalf
> Of Jon Page
> Sent: Monday, August 30, 2010 2:07 PM
> To: pianotech list
> Subject: [pianotech] YC Capo Bars
>
> A while ago I posted pix of a YC with the treble wire dug into the capo
> bars. I have the capo inserts removed and here's the photos.
>
> I called YC and they do not support this model 1996 Weber anymore.
>
> I found some round rod and tested it by hammering a piece of music wire onto
> it. The wire flattened but the rod didn't budge.
>
> I'll have a machine shop plane down the surface and mill a groove to hold
> the rod at the appropriate height. I'll not worry about the duplex, I'll
> make it straight.
>
> So much for making a quick buck on a spec piano.
> -- 
>
> Regards,
>
> Jon Page