how tight to tighten a bolt-on neck

[jonnyschanny]

Hi all. It's been several months since I've been on here. Life got in the way. But I finally got back to working on my guitar! I've got it semi finished (messed up the coating a bit--and I thought tru-oil was suppose to be easy) with the bridge glued on and am about to attach the neck and glue the fret board extension down.

I've opted to use the hanger bolt method since I was going with barrel nuts but the cracked my tenon. Got that all squared away, but now the question arises, exactly how tight should one tighten the nuts? And for those who have used the hanger bolt method before, were the nuts anything special? Will ol' steel work? The setup I have is with a washer between the wood and the nuts, partly because I had to make the holes in the block slightly bigger to compensate for the bolts not lining up perfectly (again, that was from changing from barrel bolts to hanger bolts) . I'm also concerned that the nuts might come loose over time. Has anyone experienced this, or does the tension keep them tight? Or is a specific type of nut used?

Thanks again for all the help. Ill get some pictures up soon of the progress I've made.

Jonathan

[redir]

I never actually torqued the bolts but my guess is that people would tend to over tighten them. Probably something lie 4 or 5nm would be enough which means not a whole lot but enough to where it feels snug then you give it one more good little twist.

Make sense?

If you think about it the string tension is almost in line with the neck. I'm guessing here but I would not be surprised if you could just hold the heal in place with your hand as you tune the guitar up to pitch. In any case it's not like the neck is trying to slingshot away, it would if you let it but the majority of the force is pushing into the body right at the corner of the headblock where the fretboard and body meet. The heal cap portion of the neck is twisting up so really one bolt there would probably suffice even though most use two bolts.

[Halcyon/Tinker]

Snugged but not cinched.

[LSemmens]

From a mechanical perspective, if you are concerned about the nuts loosening under use, you could always use a drop of thread locker on the bolts.

[phavriluk]

That stuff works nice (I think it best to use the most 'temporary' of them), but I think that it's of no help as wood dries and shrinks. Then you get a buzz that isn't too cooperative, the fasteners being glued in place. Belleville washers under the heads, maybe?

[LSemmens]

Thread locker is not permanent, so you can always undo the nut and/or tighten it.

[murrmac123]

Originally Posted by phavriluk

Belleville washers under the heads, maybe?

That's the answer.

To be specific, the type of Belleville washer you want is a light duty serrated safety washer.