Nature of tuning pins, why technicians prefer blue, pinblock material

[Kendall Ross Bean]

Ron~

Once again, I tend to agree.

Like you, I also perceive the Denro threads on the "blued" pins seem to be
cut AFTER bluing, whereas the Denro nickel- blued pins, well, I'm not sure
what the order of operations are on those pins, or what it is you ultimately
end up with on the threads. Berley Firmin posted me that he suspected the
blue color on the Denro nickel blued pins was actually added, and looked
like a blue machinist's layout fluid or dye usually used to mark out pieces
for cutting. If the nickel is mainly for cosmetics, I wouldn't be surprised
if they did something to make the threads look good too. Perhaps, if they
are cut AFTER nickel plating, they don't look so hot right out of the
threading machine. And perhaps the blueing furnace (or chemical dip,
whichever they use) doesn't make the threads as blue as folks expect to see.
But I could be imagining things again. Maybe it's just some nickel or
plating residue remaining in the threads on the nickel-blued pin that makes
it that weird color.

Bielefeldt in her "Wonders" book seems to indicate that, at least at AMSCO,
blueing was the final step (after threading) for both types of pins. But
that doesn't mean they don't do it differently at Denro. Maybe someone who
speaks Japanese could call them up and ask. But that's assuming that they
would tell you.

I too have found Denro pins to be quite reliable in most situations. But I
use pinblocks that are more forgiving (Maple 1/4 sawn or medium laminate
maple, depending on the piano and what was originally in there). Curiously,
I have found that the medium laminate maple blocks (standard commercial
rotary cut block from Schaff or Pianotek) actually hold the pins a little
more tightly, and uniformly, for a given drilling procedure, but the 1/4
sawn block just "feels" better when tuning. I don't care as much for the
Delignit blocks or other dense multilaminates, although I used them for
years, earlier in our rebuilding business. I think it is important to have a
material that has some give and take, especially if you are using pins that
are not that "perfect".

I think that using the Diamond pins, or some other high precision, more
expensive pin might make a dense multilaminate block like Delignit feel
better when tuning, because those types of blocks seem to require much more
precision in drilling and pinning; essentially, they are not as "forgiving".

~Kendall Ross Bean

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-----Original Message-----
From: Ron Nossaman [mailto:rnossaman at cox.net] 
Sent: Wednesday, July 09, 2008 9:25 AM
To: Pianotech List
Subject: Re: Nature of tuning pins, why technicians prefer blue


> I understand blued pins will ultimately rust in highly humid climates, 
> like they have in the Deep South or along the Eastern Seaboard. 
> Perhaps that was the cosmetic problem Steinway (and other 
> manufacturers) were trying to address with the nickel pins. (Even 
> nickel plated pins will corrode (or maybe it's the steel under the 
> plating) with time and humidity as well, just takes longer. But 
> perhaps all they needed was long enough to get through the warranty 
> period.)
>  
> ~Kendall Ross Bean

I've used blued Denros for years and years, and haven't mic'd a set since I
started using my composite block. I like blued for a couple of reasons. I
like the look better than nickel. 
I'm not a screw and plate polisher, and blued fits my semi gloss approach.
Like David, I think they feel better in the socket, for tuning, and I don't
find little chewed nickel slivers on the pin heads and lying about in the
piano years later as I do with nickel. The threads are obviously cut after
bluing, and have a nice fresh sharp tooth to them, which tells me they are
right off the lathe, aren't filled with anything or otherwise compromised,
and will do what I expect of them in the block.

As to both nickel and blued pins corroding eventually, yes, but when they
eventually do, how does a light frost of rust on a tuning pin top affect
it's function? And when they do start rusting, it's nearly a sure thing that
the blued pin will still fit the tuning hammer tip better than the nickel.
Nickel plating is, in my opinion, pretty much entirely for the sparkle.
Ron N