Andrea-
Is there a noticeable difference in the sound of the notes at the missing screws?
If the sound is acceptable, leave it as it is. These screws may have been broken long ago.
The usual method for removal is to drill a hole in the screw stub and extract it with an "easy out," but that is treacherous in this location, since the screw stubs are tightly imbedded in a hard pinblock.
You could also try to drill down with a larger drill, hoping to grind away the screw stub, leaving a larger hole to be filled, then replace the screws. Maybe breaking a string in the process.
Or maybe you can find a bolt that would thread into the cast iron hole in the plate...and it may strip out under the stress of being tightened...
Or you could try to drill a new hole through the bar and plate, between the strings and into the block. A new round head screw or bolt would not need to be countersunk into the bar.
And all of these repairs could add up to more than the piano is worth, so I hope it's acceptable to just leave it alone.
But remembering your situation, maybe it's to your advantage to develop skills in repairs like this. Consider adding a new screw between the old screw holes. Get an appropriate round head machine screw and a tap and die set. Push the strings a little out of the way. Drill a hole through the pressure bar, large enough to clear the screw. Drill a smaller hole through the plate and well into the block, appropriate size to thread for the screw. Use the right tap to cut a thread into the plate and pinblock, put in the screw. If you're not familiar with these tools, practice first on scrap metal and hardwood. (Every pianotechnician should have a nice tap and die set.)
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Ed Sutton
ed440@me.com(980) 254-7413
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Original Message:
Sent: 04-25-2019 02:23
From: Andrea Hackbarth
Subject: Broken Pressure Bar Screws
I recently tuned this 1950s Hardman upright that has two broken pressure bar screws. One of them had broken, fallen out, and was caught under the keys, and the other looked "loose" but then turned out to be broken as well. They're both broken right where the threads start on the screws and they were right next to each other in the pressure bar. See attached pics. There doesn't seem to be anything wrong with the pin block (that I can see). Any ideas what might have caused these screws to break? What's the best method for extracting and replacing the screws? This is certainly not a high level instrument, but the owner has just bought it in order to learn to play the piano and seems a bit proud of it, so I don't want to totally burst her bubble... If there's an easy fix I'd like to make it happen.
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Andrea Hackbarth
Corvine Piano Care
Palmer AK
907-435-7697
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