Re: Re: [Harp-L] polishing reeds

["Vern Smith" <jevern@xxxxxxx>]

----- Original Message ----- 
From: <glenlabb@xxxxxxxxxxxxx>
To: <harp-l@xxxxxxxxxx>
Sent: Saturday, September 27, 2008 9:17 AM
Subject: Re: Re: [Harp-L] polishing reeds


> John Kerkhoven wrote:
> > What do you use to do the polishing? You don't want to be
> > de-tuning the reed at the same time.
> Oh, but you'll be SERIOUSLY detuning the reed.  Just be prepared to
> retune afterwards.
> -tim
>
>  But, won't you have to scratch the reed to re-tune, then polish out the 
> new scratches, re-tune, re-polish, re-tune, etc, etc?  Where does it all 
> end.  With a weaker reed????  Or ... can you polish the end of the reed or 
> the near the revet (or weld) to re-tune the reed after the initial 
> polishing.  Just wondering.

I think that your concerns are well founded,  IF it ain't broke, don't fix 
it.

I would not polish a reed unless it needs tuning.  The tuning scratches made 
by the factory are usually at a small angle with respect to the reed axis. 
These scratches affect stress concentration in proportion to the sine of the 
angle.   A scratch at 90 deg with respect to the reed axis is the worst 
case.  A scratch at 45 deg is 70% as bad, at 30 deg is 50% as bad, at 15 deg 
is 25% as bad and a scratch parallel to the reed axis would not introduce 
any stress concentration at all.

Years ago, Mike Easton introduced me to a tuning tool that leaves a shiny, 
polished surface.  It is a little wheel of fine abrasive in a rubber matrix 
called a "Shofu Brownie"  They are used to polish metal dental appliances 
such as crowns and bridges.  See 
https://www.net32.com/ec/brownie-prepolish-hp-wh6-square-edge-wheel-d-41004 
They have 3/32" shanks and fit nicely in the little motorized spindles used 
to shape fingernails.  A Dremel spindle is, IMO, overkill for tuning.

I prefer a Microlux spindle like MicroMark 
http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=15230
It is about $115 including the DC power supply to make it go and shipping..

I have a little nail file spindle powered by a single AA cell from Walmart 
for about $15.  It works OK in a traveling repair kit. With some patience, 
it will get the job done and there is little danger that you will injure a 
reed.  However, it lacks torque and stalls easily.  You pays your money and 
you takes your choice.   ;o)

Vern
Visit my harmonica website www.Hands-Free-Chromatic.7p.com







> Glenn
> -------------- Original message from "Tim Moyer" 
> <wmharps@xxxxxxxxxxxxxxxxxxxx>: -------------- 
>
>
> > John Kerkhoven wrote:
> > > What do you use to do the polishing? You don't want to be
> > > de-tuning the reed at the same time.
> >
> > Oh, but you'll be SERIOUSLY detuning the reed. Just be prepared to
> > retune afterwards.
> >
> > -tim
> >
> >
> >
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