How to Achieve a Tight Neck Joint

[SColumbusSt]

One of the things I really messed up on my first build was getting the heel tight to the body. I managed to get the neck angle correct with some work but got in a negative feedback loop trying to get the heel flush to the sides. Once I got a pretty good fit the neck would be cocked too much to one side. Once I got the neck centered to the bridge again the gap on bass side of the heel would reappear. I repeated this until I decided I would rather have the neck centered and live with a gap between the heel and the side. I used 80 grit sandpaper which I placed between the heel and side and pulled to try and get rid of the gap.

I'm at that point in my second build and wanted some advice before continuing. The gap is not bad on this one but there is a noticeable one on the bass side. I got lucky and the neck angle was correct on this one so I did not need to fiddle with removing wood from the dovetail.

Any and all advice on how other folks achieve a tight fit would be appreciated.

Keith

[runamuck]

Have you back cut the cheeks slightly so that only the outer most edge comes in contact with the sides? Once you do that 80 grit is far too aggressive. Use 220.

[JonWint]

I've done a dozen new builds or neck resets. I still occasionally remove more than required on one face or another. I just glue on mahogany shim material and start adjusting again. Just be sure to check the angle and alignment often.

Every neck reset requires the addition of shim wood. It's not a problem.

I bought a roll of edge banding in mahogany for the purpose.

Order of importance (in my thinking):

• flat (or perfectly cylindrical) surface on sides next to neck block
• 1/8" or less bearing on neck edge to box, undercut inside
• rough neck angle
• neck alignment with center of box/bridge
• final neck angle

[Rudy4]

Originally Posted by runamuck

Have you back cut the cheeks slightly so that only the outer most edge comes in contact with the sides? Once you do that 80 grit is far too aggressive. Use 220.

I do the same thing, undercutting the heel face slightly and leaving about 1/4" along the outer edge of the heel cheeks.

It's particularly difficult to have a heel fit without gaps if the top of the body isn't perfectly flat where the heel meets the body. Undercutting the heel allows much easier mating of the heel to the body, even where the mating surface of the body is slightly curved.

[H165]

I agree the paper you are using is too rough. I use the papers recommended here (except I use mylar-backed (film-backed) sandpaper):

http://www.bryankimsey.com/necksets/reinstall.htm

The linked section is step 4.... I recommend reading the whole neck reset series (sections 1 through 4) Bryan posted. They are all linked together starting here:

http://www.bryankimsey.com/necksets/

[phavriluk]

This will be of no use to OP, but for folks starting their first builds why not avoid the root canal of dovetail-wrangling and build a bolt-on neck of some sort? They're going to be plenty busy with adjusting neck geometry without the complexity of out-of-square dovetail dimensions.

[mirwa]

It may sound simple, but dont rush it.

I will use 220 grit until im close, make sure you have a paint brush and clean out between each pull stroke, then switch out to 600 grit and repeat.

My process is even amounts side to side, 3 left 3 right, couple if required in centre, check, repeat, if i find im drifting off then i will do a couple more on just one side

Steve

[Robin, Wales]

It may be sacrilege to say it, but I bet that hundreds of thousands of guitars with dovetail joints have come out of the Martin and Gibson factories over the years with bad neck set angles because the focus has been on the visual aspect of the joinery. And in general that's all the buying public sees. Very few will know that they are buying a guitar that will need a neck reset due to slight and predictable future movement.

I have never built a guitar. But I look at the dovetail neck joint and shudder at the potential to get it wrong at so many points of the process.

[Taylor Ham]

Originally Posted by phavriluk

This will be of no use to OP, but for folks starting their first builds why not avoid the root canal of dovetail-wrangling and build a bolt-on neck of some sort? They're going to be plenty busy with adjusting neck geometry without the complexity of out-of-square dovetail dimensions.

The dovetail has been canonized as the only proper way to join a steel string neck to the body. Maybe alot of people buy into the hype and dont realize how much of a headache it can be.

[Rudy4]

Originally Posted by Taylor Ham

The dovetail has been canonized as the only proper way to join a steel string neck to the body. Maybe alot of people buy into the hype and dont realize how much of a headache it can be.

It's part of the "hidden smoke and mirrors" behind guitar lore. I've found it quite interesting to see details of many neck resets, easy to find because of the number of posts on internet sites. There are tons of examples of gaps and shims that were part of the "fitting" process on factory instruments. The public was sold a bill of goods and since the dovetail can't been seen, nobody is the wiser.

Part of the beauty of the Taylor NS joint is that the fit is in plain view. The neck is slightly recessed into the body using precision CNC machining and then the joint is filled with matching putty so it's nearly invisible. The Taylor joint could be thought of as the exact opposite of how many small shop builders do the heel to body fit.

The acoustics I've built use a bolted mortise design, fitting the neck heel edge to the body to control angle and geometry. Undercutting the heel to within 1/4" of the outer heel edge is the "secret sauce" behind being able to easily fit the neck to body joint.

[phavriluk]

Imagine - - - a neck joint easy to make and accurate to adjust!

And a mystery to me: The strap button. I've never seen the likes. Please explain.

Thanks!

[redir]

I use 120 grit cloth backed paper. I can't imagine using anything finer than that. Seems like it would take forever.

[SColumbusSt]

Thanks for all of the replies everyone. My first build was a bolt on neck and I still royally screwed up the appearance of the neck joint. I did manage to get the neck angle correct which I consider a major victory.

After reading these posts and reflecting (and staring at the neck sitting in the dovetail pocket for an hour) I think I finally visualized what I'm supposed to do.

[Rudy4]

Originally Posted by phavriluk

Imagine - - - a neck joint easy to make and accurate to adjust!

And a mystery to me: The strap button. I've never seen the likes. Please explain.

Thanks!

Not much to explain... I have recessed Dunlop Straploks on the majority of my instruments at both the neck and end of body. The guitar shown also has a K&K Pure Mini transducer jack located above it.

[mirwa]

Originally Posted by redir

I use 120 grit cloth backed paper. I can't imagine using anything finer than that. Seems like it would take forever.

Surprisingly it doesnt, most neck resets need under 20 thou removed, new necks yes i may start with a bit heavier grit