Neck block mortise
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Michael Thoner
- Posts: 94
- Joined: Fri Apr 15, 2016 11:22 am
Re: Neck block mortise
Sounds good. Thank you.
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MaineGeezer
- Posts: 1715
- Joined: Wed Aug 13, 2014 12:14 pm
Re: Neck block mortise
You may not need the full shimming procedure, as your joint is quite snug as is. As suggested, you may be able to just replace that small area and re-fit it.
But if you ever have a mortise and tenon that are "a rattling good fit" and need the full shimming treatment, here is my recollection of how I did it. As best I can remember, the order of operations went more or less like this:
Fit the shims (loose) so you have a tight joint when assembled and the mortise seats just a tad high (like 1/64"). The major operating principle here is that it's better to adjust by shaving down the shims (expendable and easily replaced if you screw one up) rather than by shaving down the mortise or tenon (which, if you screw them up, you are.....)
Check left-right alignment of the neck. Put a straightedge down each side of the fingerboard and see when the lines intersects the tail of the guitar. The tail wedge should be centered between the lines. If it's off: lightly sand the face of the heel on the side you want the fingerboard line to move toward the center. Test. Repeat. This process is eased if you relieve the inner portion of the face of the neck, next to the tenon, so there's maybe a 1/8" rim all around the outside that actually makes contact with the guitar body.
When left-right is correct, work on up-down angle. Put a straightedge down the center of the fingerboard. It should just graze the top of the bridge, or perhaps be just slightly above it. If it's low, shave the lower portion of the faces of the heel of the neck so the bottom will go in and tilt the neck back. If it's too high, shave the upper portion to tilt the neck up. Better to have it a tad high than too low, as if it's too high you can (within reason) fix it with a taller saddle.
When it all fits and the alignment is as it should be, glue the whole thing, including the shims. Mash it together with clamps so the neck goes down to its final position, taking up that extra 1/64" of height that you put in when you fitted the shims.
My major memory of doing this is that it involved an amazing amount of trim-and-try, and feeling confused. Don't try to fix more than one thing at a time (left/right angle, up/down angle, seating depth) or you'll get totally lost.
I don't know if that helps any or not, or just makes it worse....
But if you ever have a mortise and tenon that are "a rattling good fit" and need the full shimming treatment, here is my recollection of how I did it. As best I can remember, the order of operations went more or less like this:
Fit the shims (loose) so you have a tight joint when assembled and the mortise seats just a tad high (like 1/64"). The major operating principle here is that it's better to adjust by shaving down the shims (expendable and easily replaced if you screw one up) rather than by shaving down the mortise or tenon (which, if you screw them up, you are.....)
Check left-right alignment of the neck. Put a straightedge down each side of the fingerboard and see when the lines intersects the tail of the guitar. The tail wedge should be centered between the lines. If it's off: lightly sand the face of the heel on the side you want the fingerboard line to move toward the center. Test. Repeat. This process is eased if you relieve the inner portion of the face of the neck, next to the tenon, so there's maybe a 1/8" rim all around the outside that actually makes contact with the guitar body.
When left-right is correct, work on up-down angle. Put a straightedge down the center of the fingerboard. It should just graze the top of the bridge, or perhaps be just slightly above it. If it's low, shave the lower portion of the faces of the heel of the neck so the bottom will go in and tilt the neck back. If it's too high, shave the upper portion to tilt the neck up. Better to have it a tad high than too low, as if it's too high you can (within reason) fix it with a taller saddle.
When it all fits and the alignment is as it should be, glue the whole thing, including the shims. Mash it together with clamps so the neck goes down to its final position, taking up that extra 1/64" of height that you put in when you fitted the shims.
My major memory of doing this is that it involved an amazing amount of trim-and-try, and feeling confused. Don't try to fix more than one thing at a time (left/right angle, up/down angle, seating depth) or you'll get totally lost.
I don't know if that helps any or not, or just makes it worse....
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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Michael Thoner
- Posts: 94
- Joined: Fri Apr 15, 2016 11:22 am
Re: Neck block mortise
Where you from Geezer?
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MaineGeezer
- Posts: 1715
- Joined: Wed Aug 13, 2014 12:14 pm
Re: Neck block mortise
I thought that would be obvious -- Maine. Though there was a long stretch when I was living in exile in Massachusetts. <grin>
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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Michael Thoner
- Posts: 94
- Joined: Fri Apr 15, 2016 11:22 am
Re: Neck block mortise
Ya, Maine was obvious. I grew up just outside of Ellsworth.
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ruby@magpage.com
- Posts: 1564
- Joined: Thu May 24, 2012 8:03 am
- Location: Chestertown Maryland
Re: Neck block mortise
Thinking about the stresses on the joint, they are pulling out at the bottom and pushing in at the top of the neck block. Your mistake is in the best place it could be and all you need is a fairly close fit up there. You have good continuous contact in the lower part of the joint.
Ed
Ed
Ed M