[Harp-L] Re: Solder retune - practical limits?

[Rick Epping <rickepping@xxxxxxxxx>]

While working at Hohner I conducted a test to see where the point lies
along the length of reeds at which neither the addition nor removal of
material will affect their pitch.  Using a rotary tool with a 1mm ball end
I milled out a series of small dots along the reeds' lengths, measuring
their affect on pitch each time.  I did this on reeds of short, medium and
long length, on MS diatonic and on 64 Chromonica reeds, including long
reeds with both short and long end weights, including also the 1-blow reed
from an MS low D reedplate, where the weight extends to over half the
reed's length.  In every case I found that the "pitch neutral" point lies
approximately 1/3 the distance from the tip of the reed to the rivet pad.
Removing dots of brass from long weights that extended past this pitch
neutral point actually lowered the reeds' pitch rather than raising it.
This means that any solder added past this point will raise the reed's
pitch rather than lowering it.

The only time one might want to add solder to a reed past the pitch neutral
point would be to shorten the flexible part of the reed in order to reduce
the amplitude of its swing, so as to avoid its striking the coverplate or
reed cell floor.  In this case, only enough solder should be added from the
pitch neutral point backward to stiffen the reed; that is, only a thin
layer of solder, thereby minimising the amount of solder needed from the
pitch neutral point forward in order to achieve the desired pitch lowering.

Best regards,
Rick



>
> ------------------------------
>
> Message: 3
> Date: Mon, 3 Aug 2015 10:06:39 -0400
> From: Blunt White <playharp@xxxxxxxxxxx>
> Subject: [Harp-L] Solder retune - practical limits?
> To: Harp L <harp-l@xxxxxxxxxx>
> Message-ID: <BLU178-W245BF9CCDE10F54C4793C6C0770@xxxxxxx>
> Content-Type: text/plain; charset="iso-8859-1"
>
> A professional guitar playing friend is learning harmonica (plays in first
> position, G harp), he has problems with blowing out blow note 7 (I've
> explained why no bending down on blow 7).  My last repair used a
> replacement reed from a Bb harp tuned down 1.5 steps with solder.   This
> replacement retuning scheme was based on measuring reed thickness near the
> rivet end, the Bb replacement reed was significantly thicker than the G
> reed.   The result seemed to last longer.  This time I'm going to replace G
> blow reed 7 with a blow reed 7 from a C harp, a drop of 3 steps with solder
> (a bigger hammer).   Seems like a big drop?
>
> Interested in your thinking.
>
> All the best,
> Blunt White
> Stonington, CT USA
>
>
>