grand hinge to rim screws stripped

[Isaac Sadigursky]

Bravo,John!    This  detailed description  should be printed in the  
Journal.....isaac
On Sep 5, 2008, at 12:13 PM, John Delacour wrote:

> [ Two pictures included ]
>
>
> At 19:44 -0400 3/9/08, Jessica Masse wrote:
>
>> Besides drilling and plugging the rim, does anyone have a better  
>> way of repairing the hinge screws on a grand piano?  This piano is  
>> moved several times a year and the rim is less than 3/4 inch thick.
>
> Here's how I always do it.  It might take 30 or 40 minutes but then  
> the job is properly done and stronger than what was there  
> originally.  Stuffing things in the holes is just a way of delaying  
> doing a proper job.
>
> Line 1 shows a typical hinge rebate in a 19 mm rim.
>
> If the rim has split, protect the surfaces and clamp it together  
> before going ahead.  Leave on the clamp until everything is done and  
> the glue has hardened.
>
> Line 2 :  Plug the screw holes and trim the plugs flush.  The  
> purpose of the plugging is to avoid interference from the screw  
> holes when you come to drill out.  Mark points with an awl to centre  
> the drill exactly in the middle of the rim, which is usually not  
> where the screw line is.
>
> Line 3 : Using a 12 mm. Forstner bit or similar (see illustration  
> below) drill a line of 3 holes vertically to a depth slightly deeper  
> than the length of the screws you will use.
>
> Lines 3, 4 :  Using very sharp paring chisels, remove wood to create  
> a mortice.
>
> Line 5 :  Cut a piece of beech or rock maple to fit closely into the  
> mortise. Apply epoxy enough to fill any gaps.  Press or hammer the  
> piece into the mortise.
>
> When the epoxy has set trim the plug to the original level, colour  
> the repair and mark centres for the screws using the hinge as a  
> pattern.  Drill for the screws using the appropriate drill for a  
> very tight fit.  Lubricate the screws with a mixture of beeswax and  
> tallow before turning them in.
>
> This repair is as good as new and probably better, since the screws  
> are now turned into solid wood of the densest and most suitable kind  
> to hold them.
>
> JD
>
>
> <hinge_repair.jpg>
> <forstner_bit.jpg>
>
>
>
>
> -- 
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