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Hi

I am gradually setting this dovetail neck joint, as you look at the picture it is tight-ish (not touching) on the right and there is a gap on the left. Ist also starting to lean off center in that direction

What side of the dovetail do I need to sand to bring it back square?

I still have abut 5/16" to go before its flush with the top

J

Seems like it's touching towards the bottom sides of the dovetail but not at the top. You can always chalk the the joint to confirm.

Hi

I have chalked it and it is touching both sides in some areas, I am reluctant to sand in these areas until I know which side needs the most off to straighten it up.

If I take off evenly each side I am assuming it won't correct the lean to the left

J

John Hall has some good tutorials on fitting the dovetail. It all comes down to visualizing which way the heel will move if you remove material from one side of the tail or the other, either in the front or back, or both. While at the same time keeping the neck centered and angle correct. Take your time, after studying John's tutorials, and you will eventually develop the ability to visualize what is going to happen when material is removed from wherever. Remember, you can always glue a shim on if you take too much off.

Chuck .

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I have watched them all but its still not making much sense.

John

If I'm understanding the problem correctly. A lean to the left would indicate that the bottom left side of the male part and the upper right side would need material removing. Since you have a gap at the upper right, I would remove material from the lower left side, male part.
Does that make sense? Imagine twisting the Neck to correct the problem, now imagine which area of the dovetail would need to be removed for that to happen.

As you look at the photograph it is leaning to the right and I have a gap on the left side . Does that mean I remove material from the lower right male part ?

J

To make is easier think A C E angle first then centerline then drop the neck into the block
you need to see about 1/8 inch at the point of the saddle off the top . So what you measure at the neck block should be 1/8 inch higher at the saddle
once you get that, you then shoot for the neck center line to hit the top center line at the tail then when you dial in the angle and center , you then work the mortise to drop the neck into the block. Keep in mind you want to make this an interference fit. Keep the neck just proud of the top with human force but allow the clamp to set the neck flush.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

That is my other problem as it is currently too straight the neck needs to come down to give me that 1/32 over the bridge. At the moment its touching. I took material from both sides at the bottom edge of the cheeks to make it drop but it isn't dropping the gap gets bigger and only moves in one direction - to the right.

Perhaps we should clear up what you mean by the 'right' ? Is that the bass side or treble? Which side is the gap on? Both or just one side?
By leaning do you mean that the bass side (or treble) side of the fretboard is higher off the soundboard than the other? or do you mean that the centre line of the Neck is not aligning with the centre line of the soundboard?

Its a RH guitar so the gap is currently on the treble side - by leaning i mean off center in relation to the center line of the sound board.

J

If you're sanding the cheeks at the heelcap and a gap is appearing, but the angle is not going back, check that the face of the tenon is not butting against the neck block..

If that was mine, I'd pop the neck off and make sure that the spots (on the box) where the cheeks mate are flat, and level with one another. Either the cheeks on the neck are not co-planar, or the mating surfaces on the box are not co-planar. Straighten that out first. Either sand the mating surfaces flat on the box, or take some light sanding stroked off the BASS side of the neck cheek (not the tenon cheek..but the cheek that mates with the outside of the box.

that should straighten the neck out, and also drop it down some (since you're allowing the tenon to sit farther down in the mortise.

After that, follow John's ACE method..moving to angle. Like John said, shoot for1/8" higher at the saddle location that you measure at the 14th fret location (where the neck joins the body) Since you have the guitar fretted, a straight edge should just skim the top of a 3/8" tall bridge. Mock up a bridge or spacer, and place a straight edge on the frets, and see how you're doing. Adjust the angle as necessary, sanding the neck cheeks (not the tenon cheeks).

Once you've done that, center it again if needed, then elevate the neck or de-elevate as it were by taking off equal material (by sanding) off of the TENON cheeks.

I'd advise watching John's videos many times until you have it straight, and can visualoze what's happening as you remove material. I had to watch it like 4 times, and take notes. not because it's difficult, but because I'd spent 6 months on my first build, and I didn't want to mess it up at this late time.

Mike

this is a simple pinch joint
as I show in the video and as was suggested , you want to work the cheek area flat. Trace the heel cheeks with a pencil and sand them flat , as the pencil marks go away , that is all you need . The is you put equal marks on both side of the heel you can use them as landmarks to start working the heel. Again ACE ( establish that angle ) C watch the center line then aften you get the heel cheeks set to where they need to be you work the dovetail
Most people tend to way overthink what this joint is. Keep is simple. You want the lower part of the dovetail tenon to have the chalk , the closer to the heel the chalk the less bite you have.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Its close but I am sure its not touching, I plan to take a bit off the neck block with a chisel just to make sure.

Or I could reduce the tenon, I would need to work around the truss rod . Whats best trim tenon or the neck block ?

Hmmm...

I would usually trim a touch off the tenon in that scenario. Depends how long it is...

good point things can hold you off so chamfer all sharp corners

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

First order of business when doing a dovetail or M&T reset, remove the butt of the dovetail/tenon. Its better to have a slight gap there than not enough space which could fool you when you try to fit the cheek. After that, check the alignment and sand the corresponding cheek until you get there.

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