bridge pin material

[Ron Nossaman]

>On pin replacement, (most re stringing
>jobs)  I have been using thin CA as a driving fluid, and have noted a
>significant improvement in the cleanness of tone.

I've been CA-ing replacement pins in for probably 7 or 8 years now. Prior
to that, I used epoxy. The whole idea of renotching and replacing pins is
to improve string termination, and I'm generally in favor of whatever will
do that.


>  There also seems to be an increase in power.  

More like a decrease in power loss, but yes.



>No doubt some of the purist on the list will condemn
> the practice, stating that the pins will be difficult to replace at a
>later date.  My feelinf if they are not loose why do you want to replace them?

I don't think I'll ever understand the automatic assumption that CA will
bond steel to ANYTHING permanently. Besides, you might want to replace
nicely tight pins because they are worn, they're only tight at the bottom
of the pin, the cap is deeply grooved and the pins need to come out to
flatten it and renotch, or you've got this new Vise-Grip slide hammer
you're dying to try out and need an excuse.



>I think the CA acts as a barrier to stabilize the effects of  humidity
>swings. A couple of respected rebuilders that I know, have also tried this,
>they are understandably cautious, but their intitial findings seem similar
>to mine.   Adding the CA makes the root and cap a composite material at the
>joint, but leaves the main part of the bridge in it's normal state.  It
>takes longer to repin  the bridge, but I feel the results are worth it.

The fit of the pin at the surface of the cap is the important part, and the
CA does indeed seem to firm up and somewhat stabilize the cap. I've even
CA'd new caps.



>Over the last few years I have relied more on tapping pins, and far less on
>seating strings, with superior results,  less risk of cupping the bridge cap.
>
>Regards Roger

That's because seating strings doesn't address the real problem(s), and
tapping the pin in slightly at least addresses one of them. If the pin is
worn significantly, it can add to the cumulative damage to the cap, but if
the pin is that worn, the piano needs rebuilt anyway.

 
Ron N