[pianotech] Broken Key Repair

[Ron Nossaman]

On 11/9/2012 10:46 AM, chrisstor at aol.com wrote:

> What I noticed was missing in his description was the very important
> veneer (or card stock) splints that should be on both sides of the key.

Yes, I've always considered some kind of reinforcement necessary.


> I've come across broken key repairs (done by others) that didn't have the splints,
> only to find the the key broke in the same place because they didn't dry fit the parts
> cleanly, didn't clamp, didn't use the splints, or all of the above.  It much more difficult
> to properly repair the key the second time through because of all the dry glue blebs in
> the usually jagged end of the break.

Clamping isn't necessary, but making an attempt to get the broken halves 
back together as cleanly as you can most definitely is. Re-broken 
repairs in my experience have been from not only the lack of 
reinforcement, but an obvious disregard for aligning and refitting the 
joint when it was glued. It's always amazed me how sloppy and careless 
these reassemblies were. Use of an inappropriate glue is also a common 
find. For some reason, there were a number of people in years past who 
were under the mistaken impression that Duco was a workable woodworking 
glue. I've found lots of crunchy yellowed celluloid-like junk in poorly 
fitted failed joints from day 1-1/2, and it just makes a real repair 
more difficult as do most quick and dirty shortcuts. I find that regular 
old original Titebond works as well as, and probably more permanently 
than most, and sets up plenty fast enough to be practical. Application 
of the card stock scab over the repair quickly acts as a very effective 
clamp as the card absorbs moisture from the glue (spread thinly on the 
key) and locks on. I've never seen a well fitted, manilla reinforced, 
carpenters glue repaired break in a key fail, and it doesn't take a lot 
of time to do it right the first time.
Ron N