Unable to adjust intonation

ICBM · September 2021

Jazzthat said:

I'll wait for you guys to confirm all this and I likely would going with @ICBM ; advise and drilling new positions on the neck heel and putting some wood support in the pocket .

You shouldn’t have to drill new holes. If the neck has slipped towards the bridge, all you need to do is stop that and the screws will still go into the holes. On the Maya there was about 4mm of movement! To the point it had broken the neck pickup surround.

Part of the problem is that the bolt-on neck was designed for a Fender-style tight fitting neck pocket with an end wall, and part of it is that the mahogany-type neck wood is too soft.

Jazzthat · September 2021

ICBM said:

Jazzthat said:

I'll wait for you guys to confirm all this and I likely would going with @ICBM ; advise and drilling new positions on the neck heel and putting some wood support in the pocket .

You shouldn’t have to drill new holes. If the neck has slipped towards the bridge, all you need to do is stop that and the screws will still go into the holes. On the Maya there was about 4mm of movement! To the point it had broken the neck pickup surround.

Part of the problem is that the bolt-on neck was designed for a Fender-style tight fitting neck pocket with an end wall, and part of it is that the mahogany-type neck wood is too soft.

Ok , that makes sense . I was sort of surprise finding intonation out of adjustment , even though it is / was budget guitar .

This is a very good advise , and one to remember for future if I come across any of the bolt on guitars with such issue .

Funkfingers · September 2021

ICBM said:.
You shouldn’t have to drill new holes. If the neck has slipped towards the bridge, all you need to do is stop that and the screws will still go into the holes.

On the subject of drilling, assuming the OP guitar to be of the steamed/pressed ply top persuasion, into what are the bridge and tailpiece stud inserts secured? (More ply?)

Is it possible that the deformation has occurred in the bridge area rather than the neck pocket?

Jazzthat · September 2021

Funkfingers said:

ICBM said:.
You shouldn’t have to drill new holes. If the neck has slipped towards the bridge, all you need to do is stop that and the screws will still go into the holes.

On the subject of drilling, assuming the OP guitar to be of the steamed/pressed ply top persuasion, into what are the bridge and tailpiece stud inserts secured? (More ply?)

Is it possible that the deformation has occurred in the bridge area rather than the neck pocket?

I haven't got a clue , but it could be the combination of the two factors .

Jazzthat · September 2021

I have put a small piece of wood ( just under 3mm thick ) in the pocket .
This has almost solved the problems for most strings , apart from low E .
However saddles are still where they were .

Funkfingers · September 2021

Jazzthat said:
I haven't got a clue but it could be the combination of the two factors .

TBH, my comment was intended for ICBM.

WezV · September 2021

Flipping the low E saddle might be enough now if the rest are there

The fact you could get a 3mm block in there and still attach the neck shows it was definitely too loose. I would try pinning it in place too next time the neck is off

ICBM · September 2021

Funkfingers said:

Is it possible that the deformation has occurred in the bridge area rather than the neck pocket?

No, or you'd see substantial distortion in the top around the bridge.

BillDL · September 2021

I assume from what you said about "shifting neck holes" that this guitar has a removable neck?

If so, plugging and redrilling screw holes in the neck MIGHT be the more permanent of your repair options, the other being plugging and drilling new holes for the bridge mounting posts into the body. It depends whether your neck is mahogany or maple. Neither job is easier than the other because you have to drill the holes exectly the right diameter and at 90 degrees and that usually is best done using a pillar drill press for accuracy. New neck holes probably stand more of a chance of lasting if the neck is maple and you can plug the holes with maple. The problem with redrilling holes in the body is that you would only be moving them back a short distance and the new holes will most likely be drilled partially into the plug in the old holes. The body is usually softer material than the neck, especially if the body has any layers of plywood, and drilling into part of a wooden plug in an old hole removes part of the strength of the plug which can crack.

Wooden plugs used by good luthiers are usually made by using a plug cutting bit of the correct diameter which is something like a miniature hole-cutting saw you would use to cut a hole in a gyproc ceiling using a drill for a downlight. The reason for this is so that you can bore through the wood with the grain in the same way as the wood you are going to plug. If you were to use a hardwood dowel with the grain running the length of the dowel, then glue and knock it into an old hole, any new hole drilled partially into it is much more likely to crack the dowel down its length than a plug with the grain running across the diameter of the plug. On a guitar body a good luthier would most probably rout out a bigger rectangular area around the old hole and cut a matching piece of wood to accurately plug that, then new holes would be into fresh wood, but that requires a router, skill in using it, and entails a lot more refinishing afterwards.

Of course, that is doing things "properly". On a couple of occasions in the past I have improvised on non-collectible and cheaper guitars by filling old holes with "plastic metal" type two-part epoxy compound that dries rock solid and can be drilled and tapped without it cracking. You have to use the really strong stuff though. Your ordinary Araldite 2-part resin glue (even the very slow drying stuff) usually won't dry hard enough for this kind of job.

I think you should take the neck off and have a look at what is going on before deciding anything. Before you do, though, it would be an idea to assess the neck angle and get some idea whether you might have to shim the neck when it goes back on. If the guitar was strung up and playable and had a reasonable action without having to jack up the bridge to its maximum or deck it completely, then you shouldn't need a shim. If you take a long ruler or straightedge from the top of the nut to the top of the bridge saddles it should be running roughly parallel with the frets or perhaps going uphill to the bridge by the very smallest of gradients.

Take the neck off and have a look at the screw holes. Assuming that @ICBM is correct in surmising that the neck pocket has been compressed at the back and that the neck screw holes have been ovalled over time, you should be able to see the deformation of the holes in the neck heel and perhaps compression of the wood at the back of the neck pocket. If this is the case and you need to plug and redrill the holes you will probably have to make some kind of shim to take up the space between the back of the neck heel and the back of the neck pocket to get a tight fit again (if it ever was tight at all). While the neck is off, get a selection of thin material like strips of plastic, picks, etc in various thicknesses and do a dry fit with each of them in at the back of the neck pocket and the neck pushed into it, then do your measurements i.e. nut to 12th and 12th to about a third of the way back on your bridge. When you get them matching, and with enough space behind the saddles to compensate, you will have an idea how many mm your screw holes (or bridge post holes) would have to be moved by.

If it really is just a mm or thereabouts, you MIGHT just be able to make a solid spacer from wood, metal, or even very hard plastic to fit in behind the end of the neck and keep it pushed out from the pocket in the body by the right distance. You could then probably get away with plugging the old screw holes with thin dowels glued in with ordinary white wood glue or Araldite epoxy.

Jazzthat · September 2021

I had cut another piece of wood , this time just over 4mm . I have used black paint pen so it blends in a bit better than plane wood .
The intonation is correct now , though I haven't adjusted saddles at all ,so they are still at max position .
It may not look fantastic but , Tbh I am happy it actually works alright and I'll be able to use that guitar .
I am going to stick this thread to original Hondo as well as post some other photos of electrics etc that's now completed too .

sawyer · September 2021

Surely there wouldn't of been a 4mm gap originally? Is it possible when you've come to reassemble guitar you've put the bridge on wrong way round? Having had a quick look on Internet,there are examples with the intonation screws facing the bridge, Nashville style.

Jazzthat · September 2021

sawyer said:

Surely there wouldn't of been a 4mm gap originally? Is it possible when you've come to reassemble guitar you've put the bridge on wrong way round? Having had a quick look on Internet,there are examples with the intonation screws facing the bridge, Nashville style.

No . You can't install that particular bridge wrong way round as it has machined grooves for each string .
Not sure why intonation it's so much off , but I guess it's an old and cheap guitar , so things could go sideways ?

Howdy, Stranger!

Categories

In this Discussion

Become a Subscriber!

Unable to adjust intonation

Comments