Hi Scott
I like Melanie's response. Get a box of round tooth picks. The flat ones tend to disintegrate and not work as well.
One method that sounds about safe as can be is to remove all the hammers, flange included. Lay the action down so the hammer flange holes are now vertical. Mix a bit of water with Titebond so it's a bit on the watery side. The consistency of heavy cream comes to mind. Shim each hole with a glue dipped (remove excess), premeasured length of tooth pick. Shoe pegs I think are too big. You don't need the strength of the glue, just a slight holding power to keep the shim from leaving the hole when the screw is removed. Additionally, the watered down glue won't hold on to the screw as well once it sets. Let the moisture in the glue penetrate the inside of the hole for a while before reinstalling the screw. You'll want to catch that moment when the glue isn't hard yet but isn't fresh either. Oozing is your enemy on this job.
Make sure you don't get any on the surface between the flange and the flange rail. Seriously, it doesn't take but a hint of glue. Too much and you'll have ooze clamping and gluing the flange to the rail quite effectively. This method has some hazards so be very careful. Doing this without any glue of some kind makes for a nightmare should the flange have to be removed later when the small shim falls out during removal or reinstallation. It's a dark and crowded space in there.
When you factor in the amount of time it takes to go back and deal with an ineffective repair, it's worth it to do the job right in the shop FIRST!!
I got to wonder why these screws won't stay tight. Are the damper screws staying tight? Is there a metal component inside the hammer rail keeping the screw from digging in deeper? It's wood, it's a wood screw, it should dig in deeper ...... or are all the holes wallowed out from previous tightening? Is so, add a toothpick. It makes the hole smaller. Using a larger screw I would expect has the possibility that the screw won't fit in the flange hole.
Adding a washer keeps the screw from reaching the full extent of it's reach. When it loosens up you'll have a "tick" and a "clink" to deal with. This won't do anything but use up LOTS of time. Adding a longer screw may create problems with screw head size ......... lack of clearance from the tip of the jack.
Adding sandpaper reduces the depth the screw has to work with.
My two cents. Your turn.
Lar
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Larry Fisher
Owner, Chief Grunt, Head Hosehead
Vancouver WA
360-256-2999
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Original Message:
Sent: 11-13-2018 09:18
From: Melanie Brooks
Subject: flange screws that won't stay tight
Put a tiny sliver of wood in the hole along side the screw to shim it.
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Melanie Brooks
Brooks, Ltd. Piano Products LLC
Uncasville CT
860-848-6605
Original Message:
Sent: 11-12-2018 17:02
From: Scott Cole
Subject: flange screws that won't stay tight
I've been working on an older German vertical (1920s-30s). I took the action home to service, among other things, many loose hammers.
The design has both butt plates holding the hammers on, and a regular screw holding the flange on. While both needed tightening, I've found that the flange screws just won't stay tight. After tightening everything at the shop, I still had to do a round of tightening in the customer's home. What's loose isn't a mystery: you can see the entire flange wiggling back and forth. It's not the bushings.
The thing is, those flange screws are tight to begin with. To get the flange to not move, I had to really crank them down. Anyone have any theories as to why hammer flange screws would tend to loosen up? Any fixes? The only thought I had was to take off all the hammers and install sand paper, as is common on grands. Any other suggestions? Even when I do crank them down and get them tighter, they need very little encouragement to develop some play again.
thanks
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Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
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