[pianotech] screwed but good

[Paul McCloud]

Well, Ron, if you get THAT far into it, you can get a set of those bits
that will bite into the stripped screw head.  Wasn't there a discussion
about these new bits on here some time back?  Or maybe it was a Journal
article.  Anyway, they do work well when you need to get a screw out and
it's hopelessly stripped. One end of the tool is a drill bit which makes a
dimple suitable for the tool to burrow into.  A reversable power
screwdriver is all you need.
Paul McCloud
San Diego


> [Original Message]
> From: Ron Nossaman <rnossaman at cox.net>
> To: <tvaktvak at sbcglobal.net>; <pianotech at ptg.org>
> Date: 01/08/2009 10:02:22 PM
> Subject: Re: [pianotech] screwed but good
>
>
> > Any suggestions?  I'd hate to have to tell the client I
> > couldn't fix the problem because I couldn't get the pedal
> > box open.  He might kick sand in my face.
> > 
> > Weakly,
> > 
> > Tom Sivak Chicago
>
> Tom,
> These things were never intended to be taken apart, obviously.
>
> So much for the rational portion of the program. Now the 
> reality part. Kimball was an undisputed (by me, anyway) master 
> of the one way screw. Their case assembly troglodyte(s) with 
> high speed power drivers would spin a Phillips bit in a screw 
> head until no vestige of Phillips shaped recess remained in 
> the screw head- just a nominally conical crater. The 
> combination of no way to get a screwdriver to bite in the 
> screw head, and the (I swear (or did)), lack of pilot hole in 
> the original assembly meant these screws were likely in place 
> forever. Most times, it was duckable, except those cheek block 
> and key slip screws that had to come out to pull actions.
>
> Heat, with a soldering iron (though a torch is VERY tempting), 
> sometimes works, and is always the first attempt. You have to 
> not only be willing to get lucky, but give the thing every 
> chance to indulge you.
>
> Drilling off the head, removing the part, and attacking the 
> stubs with a Vise-Grip is also an (albeit ugly) option, and 
> often the only one when getting lucky didn't happen.
>
> You said these screws were into metal? As in machine screws? 
> That complicates things if the screws are holding a wooden 
> part to a metal part. You can't get a penetrating oil to the 
> metal/screw interface without soaking the wooden part, if at 
> all. You may be standing in front of door number 2, involving 
> drilling off the screw heads to remove the bottom plate to 
> allow access to the machine screw stubs for application of 
> penetrating oil and (definitely) torch heating, the better to 
> Vise-Grip the suckers out. Don't force the stubs or you'll 
> find yourself looking at what used to be stubs that are now 
> broken off flush (thereabouts)  with the surface, and you're 
> back to the drill. This is the REALLY ugly portion of the 
> program, where we'd rather not go.
>
> I'll stop here and hope for the best.
>
> Luck,
> Ron N
>