Martin Dovetail Neck Joint

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Oldsoldier
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Re: Martin Dovetail Neck Joint

Post by Oldsoldier »

Thanks, Bob. With the neck locked in the joint and the finger board laying (not glued) on the neck, the fingerboard extension is perfectly flat against the top. With a straight edge across the frets I am showing 1/16 or less above the crown of the bridge in its position. I could use thicker shims and see how it reacts, since I'm in no particular hurry. I appreciate your advice.
Jerry
Bob Gleason
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Re: Martin Dovetail Neck Joint

Post by Bob Gleason »

Jerry-So much of this depends on your building procedures. The differences between tops braced flat, those with various radius curves, and some compound radius and flat mixes on the same top like I do, make it difficult to generalize. The thickness of the fretboard and bridge are also big factors. My hats off to John who answers so many of the questions on this forum. However, in my experience, given a bridge of the correct thickness, if there is not at least a little bit of back tilt on the neck, you will end up with high action, and as weird as it sounds, fret buzzes somewhere after the 9th fret or so. That can lead to having to shave the bridge in the best case, or a neck reset long before it should be due in the worst case. Necks always pull up on steel strings, unless you've built them like a tank. If the fretboard extension is perfectly flat without any tension on it, you will probably have high action. Just a very small amount of tilt (I really don't deal in degrees of tilt) like having 1/16" between the fretboard and the top at the sound hole end is critical on my guitars. You don't want so much that you get a big hump at the 14th fret (or 12th if it's a 12 fret) when you glue the extension down.
tippie53
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Re: Martin Dovetail Neck Joint

Post by tippie53 »

these may help explain what you need
As Bob said there are a number of variables. The most important thing is that neck angle in relation to the bridge. Martin uses a number of bridge thicknesses I like a .350 thick bridge and I want a .375 height off the top with a straight edge to allow a proper bridge height and room to adjust the action.


https://www.youtube.com/watch?v=FNcbA1P95KE


https://www.youtube.com/watch?v=TXfyVb3L3G0
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Oldsoldier
Posts: 23
Joined: Wed Mar 02, 2016 9:50 am
Location: Northern Virginia

Re: Martin Dovetail Neck Joint

Post by Oldsoldier »

Thanks, Bob and John, for your assistance. Jerry
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