Dovetail joint fit need help with correction

[Beau J]

i suppose at this point i may nee to slightly rework the cheeks to change the angle slightly and the possibly add anoth shim and rework the depth of the neck. sorry for all the questions etc. this is a huge learning curve for me but very inertesting

[Beau J]

I will work till I get it perfect or run out of wood. Lol

[ken cierp]

Lets make sure you understand the geometry here first -- I don't see any reason to remove more material from the cheeks, you need to get the surface of top surface of the neck even with the sound-board. Dropped sraight down in the mortise not tilted.

[Tim Benware]

OK, maybe I'm interpreting what he is saying wrong, maybe not but when a neck angle gets out of whack necessitating a neck reset and the heel is flossed back to get the neck angle back to where it should be there is often a gap under the FB even though the projection line is correct. If this gap is slight I will just glue the extension down a bit and it will have a slight fall off from the 14th to 20th fret, no big deal in my mind. If the gap is, let's say, more than slight, I fabricate a wedge to go under the FB to take up the gap. It doesn't raise the FB at all it just removes the gap and maintains a straight line to the bridge with the correct neck angle.

If however your gap is caused by the neck line sitting proud of the top then indeed it needs to be lowered. If the neck line is flush with the top and that causes the gap you may need the wedge.

[ken cierp]

Tim agreed

Beau can respond -- I believe the neck is not yet flush with the sound-board and that is what needs correction. By dropping dwon in the mortise - not changing the angle (again)

[Beau J]

I think you are both correct. I will post picture to clarify my puzzle. The neck is still on center. The back of the tenon, the part nearest the sound hole, is now .005 inches below the sound board. The front of the tenon, where the body and the neck touch, is .034 inches below the sound board. If i lay a straight edge along the neck, with out the fret board, I have 3/16 inch between the sound board and straight edge. My conclusion is the while adjusting the tenon I have increased the neck angle slightly some how.

[ken cierp]

If you don't have it, as mentioned early on --- you must get Bill Cory's instructions for building Martin style guitars-- it shows the correct sanding method including cause and effect for preventing what happend here. Unfortunately you've gone past the cure and created a different problem.


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