Reseating neck after removal: swolen dovetail

[Wes Yates]

First off, new to the site so pardon any breeches in etiquette. I am restoring an early 60s Kay archtop acoustic and had removed the neck. The parts are dry now but the dovetail seems to have swolen. The neck wood is poplar as i can tell (color and smell). The neck does not seat as far down now as it did. There is about a 1/4" lift in the neck. I can reduce the dovetail to fit the cavity, but want to know if that is the right path to go down. I will post a pic soon.

This was an old, beat up guitar that had some REALLY poor restoration done on it as well, the neck was separating from the body at the heel causing the string angle to be really low to the bridge. While correcting that (and since this is a project guitar anyway), i am totally restoring it back to as close to original as possible.

I'm refinishing it, replacing the fretboard, adding a pickguard (missing), replacing the truss rod. Otherwise using as many original parts as i can.

Thanks

I also build cigar box guitars on the side.

-Wes Yates

[Wes Yates]

Ned,

Yeah, I'm gonna make sure I have a copious amount of gelatin (hide) glue in the dovetail -- especially at the heel to ensure the seal is tight and the fit is exact. -Wes Yates

[Wes Yates]

Paul,

Well, I'm pretty sure its poplar as there is a two-tone wood, larger/thicker grain, yellow/greenish, the darker heartwood is green/gray and when cut smelled like a horse stable (I cut poplar frequently for cigar box guitar necks and the smell is unmistakable). Thank you tho for the comment!

-Wes Yates

[Mark Pollock]

Okay, I'm NOT SPEAKING FROM EXPERIENCE HERE...

Would stabilizing the soft wood with CA glue help this situation at all? A good soaking and drying to increase hardness? Of course, I don't know what kind of glue would then hold the neck in the pocket - I may have just found my own issue.

[Wes Yates]

You know Mark, That might not be a bad idea as CA does soak into wood. CAVEAT: CA is CA. What you are trying to do is change the characteristics of the wood. When building CBGs, I have used CA for quite a few structural... enhancements so for [me] its not unheard of. I would assume you are going to use hide glue for wood-to-wood bonding. I am.

I think CA is really an interesting material which as its place in luthierie.

On that note: I am 'shimming' my dovetail since I had to cut back the heel angle from the bottom of the heel up, thus making the base of the dovetail thinner and more loose in the joint. I am shimming with (believe it or not) strips of index card applied with CA. What is paper but wood anyway right? Different form, that's all. I use it as shims quite often when I build CBGs. I will still use hide (gelatin) glue.

-Wes Yates

[Ned Knepp]

I used index cards once for shims but decided against it because I realized that most processed paper has enough acid to make it break down over time. My hope is that the joints I make won't need attention for several decades and I don't know how well processed paper will maintain it's cellular structure before it introduces some "give" to the joint.  I also think I can shave wood to a much finer wedge shape to better fill the voids in the joint so that I don't have to depend on thick layers of  glue as a structural element in the joint. 

Hide glue is very good at drawing together a joint but pockets of it tend to leave voids in the joint because of the shrinkage. Take apart an old chair and you will find that almost every joint will have dried hide glue that is filled with bubbles where a void was created.  I prefer to make the joint as tight as possible and use only as much glue as I need to hold the wooden joint together. I don't like to depend on glue to fill voids.

[Wes Yates]

Interesting point Ned. I hadn't thought of the paper breaking down. The shims I made are laid on with CA and covered in CA to make a hard surface. I would think it would last longer than straight glued paper.

That brings an interesting thought: what if one were to use paper laminated in hide glue in layers as repair patches or similar? I would think the hide glue would prevent the paper from deteriorating in as much as any other wood. OR you could use kraft paper which should be much less acidic. OR hide glue might be more acidic thus contributing to paper breakdown. I dunno.

-Wes Yates

[onewent]

If the concern is a weak or loose joint due to the poplar block and dt, why shim with paper?  I'd use a nice mahogany or poplar shim, glued to the dt, then carefully fit to the dt in the block, and glue up with hhglue..the shim glued to the dt on the neck may help with any creep of the weakish, punky poplar.  The female part of the dt in the endblock should be solid, assuming it's glued and secure.  I've not had a problem with this method on the 'factory' guitars I've reset.  Plus, CA glue on paper won't allow the hide glue to work to its optimum.  I know guys who use paper shims, but it's so easy to make one from wood, why risk paper?  Tom

[Harmon Gladding]

Could a neck dovetail of softer wood be effectively hardened by drilling and gluing in a hard dowel in some direction or other?