[pianotech] Field hammer shank replacement

[David Nereson]

    I have a brad-point 7/32" bit with a hex drive end that fits 
my cordless screwdriver.  With old cedar shanks, I don't try to 
pull out the old shank; I just start drilling.  One can feel 
when the bit hits the harder maple at the bottom of the hole.
    But with maple shanks, I use the method of first drilling a 
#39 hole into the old shank, then dribbling a few drops of 
wallpaper remover/vinegar mixture into the hole, then driving a 
short drywall screw into the hole.  Then the screw is heated 
with a cigarette lighter or mini-torch until it steams and/or 
bubbles, then the screw & shanks are pulled out as a unit with 
the shank extractor.  This works most of the time, and when it 
does, is superior to using one of the drill bit guides 
available.  But when it doesn't, then I drill it out with the 
bit mentioned above.  I keep a little bottle of the remover 
liquid, an eyedropper, & the #39 drill in a metal Band-Aid box 
in the car.
    The butt is replaced in the action, then the new shank 
inserted and marked for length with a neighboring hammer as 
reference.  I cut it to length with a small hacksaw or Swiss 
Army knife saw blade, knurl both ends either with the sawblade 
or the edge of a file, mark which way the grain will face 
(baseball bat label theory), do a dry fit, then swirl glue onto 
the ends and after assembling, hold things in place until they 
set.
    I'll admit I don't have a great way of duplicating the 
proper angle in the hammer molding of angled hammers and am not 
impressed with most of the jigs available.  If the old shanks 
pulls out, great -- it's already "pre-drilled."  But if it 
doesn't, you have to guesstimate as close as possible, or buy 
one of the awkward, not-as-accurate-as-they-claim jigs.  I 
usually use the shank clamp and extractor tool to pull the old 
shank out of the molding.  If too short, I saw it off flush, 
hold the molding with a Vise-grips and drill it out, 
"eyeballing" the angle.
    --David Nereson, RPT


----- Original Message ----- 
From: "Michael Staples" <mastaples at gmail.com>
To: <pianotech at ptg.org>
Sent: Saturday, September 11, 2010 12:02 AM
Subject: [pianotech] Field hammer shank replacement


> When you have to replace a broken, crumbly (cedar?) vertical 
> hammer shank in
> the field, what method and tools do you use to do the job in 
> an efficient
> and accurate manner?
>
> Thanks,
>
> Michael Staples
> PTG associate member
>