Doweled and Fully Fit Pinblocks - Extracting the old pinblock

Kendall Ross Bean kenbean at pacbell.net
Mon Aug 4 03:10:03 MDT 2008


Michael Spreeman wrote:
 
>>How are y'all removing your original blocks?  I've seen 3 styles of Stnwy
stretchers. On the ones with an angle on the outer face and perpendicular on
the inner face, we had an angled piece of spruce we would we would tape to
the front of the stretcher in to run the router along (with the Bolduc
cutter). This results in a perpendicular cut at the block joint.
 
Michael:
 
That's a good trick!
 
I don't know if anyone else answered your question yet, but there are a
couple of ways I have tried it. The first method I saw them using in one of
the better known New York rebuilding shops many years ago. This involved
cutting the old pinblock out with a demolition type saw. The problem with
this is you could only get so close to the stretcher and then you would have
to chisel off the last 3/4" or so by hand. This worked well for me for many
years, it was just time consuming. I made a special fixture to protect the
stretcher, and padded it with felt. I was considering the Bolduc
cutter/router setup though, until someone showed me a much faster way (at
least for where I live, read on.)
 

 
Some years later a very experienced rebuilder visited my shop and showed me
an easier way. He said he just broke the stretcher to pinblock joint with a
mallet. He himself used a leather mallet, but I have had just as good
results with my 3 lb sledge I use for stringing and a stout block of
pinblock material or Finn birch.  Here in California the humidity isn't that
high (about 30% to 40% where I am, but sometimes up to 50%) so the glue is
more brittle and the joint breaks easily (no, you don't have to whack it so
hard it breaks the stretcher). A few judicious taps will let you see how
much of a swing you need. Usually I can separate the entire joint within a
minute or two. 
 

 
Then the task is to cut the dowels. With wedges or something else to hold
the joint slightly open, locate and cut the dowels with a hacksaw blade. A
piece of cardboard will prevent damage to the stretcher finish or veneer.
The advantage of this is that it allows you to remove the entire pinblock
fairly intact to use as a pattern for the new one.
 

 
Some technicians are concerned this won't work without damaging the
stretcher.
 
I would imagine, from what I have heard, that cutting the old block out with
the Bolduc cutter, (or a Sawzall or Tiger Saw) may be be necessary in high
humidity areas, maybe that's why they sawed them out in New York. Probably
in the West or Desert States where it's dry you would have better luck with
method #2. Having sawed them out, I definitely prefer breaking the joint, if
you can, it's much faster. I have done this with several blocks now and
there has never been any problem with stretcher damage. Some veneer might
occasionally come off the back of the stretcher, stuck to the pinblock, but
this is usually not a problem, (and usually happens anyway even if you saw
the block out and then chisel out the remains.) Usually it makes a pretty
clean break, simply because the hide glue is brittle.
 
I believe it was Art Reblitz who said in one of his player rebuilding books
that player stacks that would easily break apart in Colorado would have to
be sawn apart in Chicago, because of the strength of the hide glue in a
humid environment. Apparently it's harder and more brittle where the climate
is drier. Depending on your climate, you may or may not be able to break the
joint this way. But it's worth a try. I know I'm not the only tech out here
doing it this way.
 
Being a pianist, there are a couple of tools I just think are too risky for
me. Although I know the Bolduc cutter can be used safely in the right hands,
I just have my own reservations about using a 4" blade on a hand-held
router. The piano supply house that sells them strongly recommended that
they only be used on a router with a trigger switch immediately under the
finger "just in case". That was enough for me. That puts it in the same
category for me as a radial arm saw, which I also will not use, because you
always have to try and anticipate just exactly where the blade is going to
be, or what might go wrong, which varies with each setup.
 
~Kendall Ross Bean
 
PianoFinders
www.pianofinders.com <http://www.pianofinders.com/> 
e-mail: kenbean at pianofinders.com
 
Connecting Pianos and People
 
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