[pianotech] Fwd: WNG plate bolt installation

[Alan Eder]

List,


I recently participated in an installation of the WNG bolts with Richard Davenport. Here is how he plans to do it on the next go-around.


Alan Eder







-----Original Message-----
From: Richard Davenport <rdpt at aol.com>
To: reggaepass <reggaepass at aol.com>
Sent: Mon, Oct 31, 2011 7:01 am
Subject: Re: [pianotech] WNG plate bolt installation


I already know what I will do differently next time. It starts by drilling out the old lag bolt holes and plugging them with a 1" maple dowel. After gluing in the board, Ill put in the plate and mark the centers of all the rim bolt holes. Then I'll remove the plate and wheel my drill press over to the piano. I'll use a 7/8" Forstner for the first hole, followed by the 9/16" Forstner for the second hole and finally a smaller 25/64" long aircraft twist drill for the final hole that holds the lags. 13/32" is too large. Both Forstner bits will be used in an extension.


This system corrects for two problems. The original Steinway lag holes are not at 90° in any direction. The result is a WNG bolt that touches only a small area of the plate boss. The smaller 25/64" aircraft drill will tighten up the lag bolts so they don't turn when you tighten the retaining bolts. This may not be a problem with newer rims. I had a heck of a time with the 1913 A I just strung. The old wood didn't hold the lag securely. I had to clamp the plate down on both sides of the WNG bolt to keep it from turning down when tightening the retaining bolts.


Incidentally, Bruce Clark at Mason & Hamlin dowels the old holes too. This is where I got the idea.


RD

-----Original Message-----


From: Encore Pianos <encorepianos at metrocast.net>
To: pianotech <pianotech at ptg.org>
Sent: Fri, Oct 28, 2011 6:02 am
Subject: [pianotech] WNG plate bolt installation



Hi:
 
This is addressed to those of you who have been using the Wessell, Nickel, & Gross Perimeter Bolts.  I am trying to refine my system for installing them, and I find the recommended WNG installation system leaves much to be desired  As you  know, we are required to drill 3 holes.  WNG recommends drilling the first hole with a 7/8’ spade bit to a depth of about ¼”, the second with a 9/16” spade bit to a depth of about 1 ½”, and the third with a 13/32” aircraft or electricians drill to a depth of about 4 1/8”.  
 
I think the spade bit drills are terrible, they chew up the wood and don’t leave a clean hole, and they do not center very well on top of that.  Nor have I found that the electricians long drill centers well either.  Basically getting all three holes to center consistently is a crap shoot.  There has to be a better way.  
 
Of course, the rim is in the way. That limits our options considerably as far as what other tools we might use.  The drill bits we use must either be long enough to have the drill work above the rim top, or we have drill extensions with the proper bits set in them that will allow the same. 
 
Here is the plan of attack I am contemplating:
 
I made a drill guide out of a block of wood that is 3 ½” tall by 7” long x 1 ½” deep.  I drilled a 5/8” hole off centered, and same with a  13/32” hole .  The block is mounted on two 3” feet that raise the block and allow you to see the drill bits going into the holes, and leaves room for the movement of the bits.  
 
The 5/8” hole serves as a guide for a 3/8” shank forstner bit extension that is 10” long x 5/8” in diameter, which I got from Woodcraft.com   Most Forstner bits have a 3/8” shank, and that size is hard to come by at a hardware store, not to mention that the Irwin drill extensions we commonly see are a WCPOS and not worth buying.  I paid $35.00 for my Wood River extension.  
 
What I want to do is use 3 Forstner bit sizes to drill my holes – 7/8” for #1 hole, 9/16” for #2, and 3/8” for the final hole.  I can mount all three in my Forstner extension, and use it in my guide to keep everything at 90 degrees.   The 3/8” forstner bit is too small for the threads of the WNG bolt, so I will chase that last hole with my 13/32” aircraft drill.  The .031 difference in size between the hole and the drill should be small enough to allow it to center well in the hole.  Indeed, the 3/8” hole does not need to go fully to the bottom, only deep enough to serve as a sufficient guide to the 13/32 hole that will then take it to full depth.  
 
That is how I believe I can get good and consistent results.  
 
I would love to hear others input on this.  If you have a better way, I am all ears.
 
Will Truitt

 

 

 

 

 
 
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