[Harp-L] Re: reed polishing - revised

[David Pearce <harpdog123@xxxxxxx>]

Thanks for that excellent info Vern.  Greg at 1623customharmonicas.com replaces broken stainless steel reeds with polished reeds as he believes that the polishing process increases their longevity and has never had to replace one of his polished reeds.  He compensates for the pitch change caused by the polishing by using a reed that is 1/2 or a whole step higher in pitch.  Players have been reporting that certain stainless steel reeds on some of the seydel harmonicas seem to die within a short period of time.  Have you ever had to replace any of your saxony reeds?

David   



 
 

-----Original Message-----
From: Vern <jevern@xxxxxxx>
To: David Pearce <harpdog123@xxxxxxx>
Cc: harp-l <harp-l@xxxxxxxxxx>
Sent: Sat, Dec 27, 2014 4:50 pm
Subject: reed polishing - revised


Please disregard my previous email. Here is my revised response.  I deleted the 
part about polishing both sides of the reed. I understand that the finish on the 
stock is better than the machined top side. We are talking about polishing the 
top side of the reed only.  My conclusion is the same but the deleted item is 
not a valid reason.   Mea   Culpa.

Vern

Short answer: Yes.

Long answer:
In general, fatigue cracks can occur at stress concentrations arising from 
abrupt changes of cross-section thickness.  Polishing is intended to smooth out 
such changes.  This is the weak rationale for the notion of polishing reeds.

Howeverââ..
...SS is very resistant to fatigue.
âthe Seydel reeds are not very rough so there are not appreciable changes of 
cross section.
âIf polishing removes any material, you will lower the pitch.
âif polishing removes any material, you will change the stress distribution 
along the reed, possibly creating stress peaks and doing more harm than good.
âyou will never know whether or not the polishing extended reed life.  A valid 
test would require cycling many polished and unpolished reeds to failure under 
identical conditions.  I doubt that even the manufacturers have done anything 
like that.

IMO, there is much to be lost and little to be gained.   
For this reason, I donât bother to polish my Saxony reeds.

Vern