John D/Stitching Cracked Plate

[Carl Meyer]

Can't resist getting in here.  Plates aren't what they're cracked up to be,
you know.

Here's my totally biased opinion.

The reason I'm skeptical of welding is that I don't know a good welder.  I
wouldn't recognize one if I saw one.  All my peers insist "I have a welder
that can weld anything".  I'm old enough to know that flakes exist in all
fields.  Even tooners.
Joe says he ran into one that used an acetylene torch.  What was he supposed
to use Joe, a charcoal lighter?

Welding cast iron is risky since it expands and will be hardened if not
annealed properly.  It can be warped by someone who doesn't know what he's
up against.

An unsuccessful weld can ruin your whole day.  I happen to like to peel my
own banana.  If a guy screws up a job, I'm not apt to ask him to fix it. If
he couldn't do it right the first time, why should I think he can do it
right at all?

I've repaired a couple of plates and here's my approach.

I try to figure out why the plate cracked.
My first choice would be to correct that reason.
If cosmetically possible and structurally advisable I would first think of
splinting, patching , reinforcing or what ever to strengthening it.  It
might take the application of steel bar, screws, metal filled epoxy etc.
This is all stuff that I can do without outside help.

Next choice would be metal stitching.  I take it that there are different
techniques for this.  I'd like to know the details of the ones other than
Lock-n-stitch.  I attended a demo of their procedure at Bob Davis's shop in
Stockton, Ca. and they did a class at Reno that I did not attend.  So, I'm
only familiar with that one company.  I arrived a complete skeptic and left
amazed at the procedure.  If you can visualize a screw designed to pull the
two sides of a crack together rather that forcing them apart, then you got
the idea.  Best part is that for a simple plate repair an outlay of about
200 dollars will get you enough tools and stitching pins to do a repair or
two.  I'm going to post a photo of the pin so you can see the angled threads
of the pin that will pull the two sides together.  You'll need to drill,
tap, and spot face (all special tools) before inserting the pin.  Pins are
overlapped to get a firm gas tight repair.  Call them at 209/ 632-2345 to
get their instructions and prices.  They are in Turlock, Ca.

You know, I doubt I would ever choose welding, even as a last resort.  But,
lightning might just strike.  I hope I'm not near the piano when it happens.
Not many thunder showers in this bay area.

If someone knows the details of competing systems I would appreciate the
info.  Attachment follows.

Cheers

Carl Meyer  Assoc. PTG
Santa Clara, California
cmpiano@attbi.com






----- Original Message -----
From: "Joseph Garrett" <joegarrett@earthlink.net>
To: <pianotech@ptg.org>
Sent: Sunday, December 16, 2001 11:36 AM
Subject: John D/Stitching Cracked Plate


> John,
> Thank you for the clarification of the "Stitching" process. As, I have not
> seen the process done, I was laboring under some poor info. As you explain
> it, it sounds quite acceptable. I'll have to check out the local
> availabilities of such. I don't currently have a cracked plate to deal
with,
> but you never know when "lightning" will strike. <G>
> Regards,
> Joe Garrett, RPT, (Oregon)
>
>