Re: [Harp-L] re: Breaking-in



The pitch flattening occurs when decreasing gaps as well, which is what needs to be done 99% of the time on a diatonic. Also happens when bending the tongue in a manner that doesn't disturb the reed/plate contact point, such as slipping a shim under the reed 2/3 of the way back and pressing your thumbnail directly behind the shim (between that point and the base). I can see how your scenario could have a pitch-flattening effect, but it's not the same situation. It's obvious that bending the reed beyond its elasticity point would weaken the crystaline structure, which demonstrates itself by the flattening of pitch. The fact that it goes back up in pitch, even if you immediately put it away and come back to it a few days later (no corrosion buildup from playing, influencing stiffness/mass), could reinforce the theory that the molecules of the reeds are doing something that correlates with the break-in scenario.



----- Original Message ----- From: "Vern" <jevern@xxxxxxx>
To: "Joe Spiers" <joemopar@xxxxxxxxxxx>
Cc: "Harp L Harp L" <harp-l@xxxxxxxxxx>
Sent: Saturday, May 15, 2010 6:24 PM
Subject: Re: [Harp-L] re: Breaking-in



When you manipulate a reed and its pitch flattens, I think that you have very slightly changed the last point-of-contact between the plate and the reed base. A tiny portion of the base may not be in contact with the plate and may be vibrating as part of the reed. This seems to occur most when increasing gap.


Vern

On May 15, 2010, at 1:18 PM, Joe Spiers wrote:

If you manipulate a reed (reset the arc or even change the offset), often it
will flatten the pitch. The pitch of the reed will return towards where it
was after as little as a few hours to as long as a couple weeks, sometimes
longer. Some reed "recipes" react this way more dramatically than others.
Would you consider this as some sort of evidence of the molecular "healing"
that Sissi describes? I think it makes sense and fits the practical
experiences I have, for what it's worth. I thought it was a very interesting
article and am glad to see this discussion.
Joe Spiers



----- Original Message ----- From: "Vern" <jevern@xxxxxxx> To: <msky@xxxxxxxxxxxxx> Cc: "Harp L Harp L" <harp-l@xxxxxxxxxx> Sent: Saturday, May 15, 2010 3:01 PM Subject: Re: [Harp-L] re: Breaking-in


The material of the SS reeds is likely to be more fatigue resistant than copper alloys. However, unless I see evidence to the contrary, I conclude that any new SS reed is as strong as it is ever going to be and a brief period of gentle playing won't increase its fatigue resistance. A period of gentle playing might get you into the habit of playing gently, thus causing your reeds to last longer.

Vern

On May 15, 2010, at 10:15 AM, msky@xxxxxxxxxxxxx wrote:

I just sent away for a 5-pack of Seydel 1847 silvers. I generally use Sp20s, but I've enjoyed the one 1847 silver that I presently own more than any other harp I've tried, and I felt like I deserved a present from myself.

Anyway, having read Vern's comments below, and not being a metallurgist, is breaking-in a good idea for the stainless steel reeds? If so, what would be the recommended break-in method?


Surely you do not claim that there is something exceptional about harmonica reeds >that exempt them from the properties of brass or bronze.

There is an effect called "coaxing" that occurs in iron and mild steel but not in non->ferrous alloys. A long period of cycling at low stress followed by long periods of >increased stress at successively higher levels can increase fatigue life. However >those conditions are not met by harmonica break-in because the reeds are not mild >steel, the break-in period is short, and there are no successive long periods of >gradually increasing stress.










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