Machine screws and inserts for a bolt on neck?

[badbrain]

I've done this in a homemade guitar, worked out okay. I can't say that I notice a huge difference in tone, but it does allow for a really tight fit between neck and body. I would recommend using stainless inserts and bolts. I ordered them through a furniture supply catalog. I would stay away from brass, especially if you are going to glue the inserts in (which I did). I also tapped the holes in the body before gluing the inserts in.

[headless]

 

Lowes and Home Depot both carry threaded brass inserts. You simply pick the size you want to match the machine screws used. I use #6's for things like cavity covers, and 1/4" for bolting on necks (although I've switched to knockdown bolts on acoustic guitars). Here's how I install them. First, buy a few extra so that you can get used to installing them in scrap. Some experimentation is required to get the right size hole (in scrap first) that will hold the insert tightly but will not split the wood when the insert is installed. Cut the head off of one of the machine screws - it helps sometimes if you get a longer screw for this, but it isn't necessary. This will be chucked into a drill and used to install the insert. Put two hex nuts on the screw, threading them on just slightly farther than the length of the brass insert. The insert will snug up against the nuts when you install, and who doesn't like that? Apply a little bit of wax to the threads of the chucked screw. Then thread on the threaded insert. I use to leave the slotted end of the insert pointing up so that I could remove them with a screwdriver, but don't do that anymore because it looks crappy and it's too easy to strip the slot when trying to get them out anyway. So, slot end down. Before inserting the insert, I usually bevel or countersink the hole just a bit. I like to have the inserts sit just below the surface instead of dead flush, but that's just me. Don't use a ton of glue - you don't want any inside the threads, and it's not even entirely necessary for the job. Apply a little bit of glue to the outside of the threaded insert. You could use epoxy, but superglue works too. This not only holds the insert extra-securely, but also lubricates it a bit when it goes in. Put the chucked insert into the hole, make sure you're as close to vertical as possible, then slowly drill that sucker in. Reverse the motor on the drill and you should be able to easily unscrew the "bit" from the insert. Done.

 

 

This afternoon I got a chance to try your machine-screw chucking technique.

It did work well, but the next time I do it I think I'll make a slight mod.

 

I found that I couldn't get a good grip on the bolt with my keyless-chucked drill (the kind with a variable clutch). It seemed that the tips of the bolts threads didn't provide much surface-area for the chuck to grip and the threads were delicate and wore-away quickly.

 

Next time I think I use a bunch of nuts on the machine-screw. Enough so that the bolts will extend into the chuck and their faceted surfaces will give the chuch something to grab hold-of.

 

Really, I don't think I'll ever have another "bolt-on" neck guitar without installing these threaded wood inserts (unless it needs to be kept stock to retain it's value).

 

I work on my guitars and I've always dreaded that eventually I'd strip the wood in the neck holes and have to do a repair. With these threaded inserts, it's almost a joy to remove my guitar's neck---almost.

 

I think that most people recommend the #8-32 inserts and bolts, but after having used #6-32's I find it hard to believe that the larger fasteners are really necessary (I prefer to remove the smallest amount of wood possible). I'd be interested the opinion of a fastener-knowledgeable forumite about this.

[tlbonehead]

I visited a guitar repair shop recently, and the guy recommended using machine screws for bolt-on necks. He puts some sort of threaded insert into the neck and uses machine screws rather than wood screws. He claims it improves tone as well as preventing the wood screws from stripping. Has anyone tried this? Is there any tonal effect? It seems like a pretty easy mod and that more people would do it (or even manufacturers, actually) if it was a great idea.

you mean just standard threaded inserts? Sure, I've done that on guitars necks whenever the screws strip out, as well as on many other things, especially where bolts/screws get taken out periodically. Pretty common item and practice.

[tlbonehead]

you will cross thread it

not if you start your screws with the neck straight with the body.

[MahaloVision]

 

It seemed that the tips of the bolts threads didn't provide much surface-area for the chuck to grip and the threads were delicate and wore-away quickly.

 

 

Yes. You have to get an overly-long bolt and cut off the top so that the chuck grips on the round bolt shaft, not on the threads. I can imagine that must have been frustrating. If you put the nut on first, then cut off the excess, you should be able to easily remove the nut. You shouldn't need more gripping power at the chuck than what you'd use on a standard drill bit.

[-Assy-]

theres really no need to make this mod unless the guy who assembled your bolt on neck guitar stripped the holes, in which case you could be clever and use dowells and glue and redrill, or you can dive into this project or pay someone to do it for you.

 

It would make things more convenient if you are switching necks a lot, but if you know how to thread a hole in wood and keep a screw in those threads, you will never need one.

 

simple drill the hole two sizes too small (if its a rosewood neck or something as hard as that, one size will do), thread your screw in. if you remove the screw, when you go to put it back in, simply get the screw ready to go in, spin it counter clockswise, and you will feel the screw drop into threads, no stripped threads.

[bvr775]

ts.. I dont really recommend inserts unless your just bending the hell out of the neck. I use inserts because i dont abuse guitar necks. I wouldn't know where to order em online because i get them from fastenal down the road from me.

 

dont go to lowes or home depot for the inserts. main reason is they are cast not machined or quenched and tempered . cheap casting has a definite disadvantage when using them in an an application where force is exerted from all angles in something like a neck.

You can use a stainless heli-coil or carbon(quenched and tempered) heli-coil, but be warned, you can not force them in. The hole must be pre-drilled and taped with a flat tap or the threads will spread. you must also epoxy them into the hole. I ,however, do not recommenced heli-coils because they are not designed for wood and you will have to know the pitch and thread count(coarse or fine) of the heli-coil after its threaded into the wood to order the bolts or machined screws. way to much to go into here.

 

Ive run across a few inserts on fenders and yes they can be shimmed. The ones fender uses are machined brass inserts. these are the ones you want if your set on this type of repair. I have never have to repair a fender with the inserts because they are indestructible. it looks like 1/4-20 machined bolt though.

 

 

main thing to know here..this is a very intrusive repair or modification. If its done wrong you will be be buying a new neck. you will need a drill press and you will need to practice on some blank wood before doing it and they are epoxied into the neck. SO ARE YOU ABSOLUTELY SURE YOU WANNA TRY THIS.

[tlbonehead]

 

 

 

I think you are making this sound far more complicated than it really is.

[nanobug]

If I were building a guitar I would do this without question, and if the holes on my strat somehow got stripped I would sooner do this than dowel the holes. Aside from those two situations I'd avoid trying to 'improve' an otherwise fine bolt-on for minimal gain. It's not worth risking accidentally damaging it and rendering the instrument unplayable or worse off than when you started. Leave well enough alone.

[tlbonehead]

 

theres really no need to make this mod unless the guy who assembled your bolt on neck guitar stripped the holes, in which case you could be clever and use dowells and glue and redrill, or you can dive into this project or pay someone to do it for you. It would make things more convenient if you are switching necks a lot, but if you know how to thread a hole in wood and keep a screw in those threads, you will never need one. simple drill the hole two sizes too small (if its a rosewood neck or something as hard as that, one size will do), thread your screw in. if you remove the screw, when you go to put it back in, simply get the screw ready to go in, spin it counter clockswise, and you will feel the screw drop into threads, no stripped threads.

 

 

except it is certainly no more difficult to put the threaded insrts in than to drill out and glue dowells in and redrill.

[bvr775]

 

I think you are making this sound far more complicated than it really is.

 

 

its not complicated, but this is becoming a common mod. ive repaired more than with broken cast inserts or mis drilled holes than i care to. the bad thing is, is the mod based on a guitar myth. the mod does little bit of nothing and the traditional hard wood plug repair is still the best way to fix a stripped hole

 

 

and after reading a few of the replys... some of you really need to watch what you say in these threads. Just posting to get you count up is really irresponsible. this is one of the most read guitar forums online. remember only a few people may post but you got a few hundred reading and saying" thats a good idea".

a while back I had an early 50's tele sitting on the table that someones' kid tried to do something because they read it here. They were just trying to clean the guitar for their dad, but because they got bad info they almost ruined the guitar.

[O'Rourke]

It's a much, MUCH more long-lasting neck joint than just running wood screws into the neck wood. You lose some wood every time you remove a wood screw, the connection gets weaker and weaker every time you remove it.

 

That doesn't happen with metal inserts unless you overtighten and strip them out, but doesn't happen untill you apply 10x the torque that would strip a wood screw threaded into bare maple or whatever wood your neck is made of. Also, if the inserts strip they can be replaced with new ones since the threaded part on the inside is the only part damaged.

[ihavenofish]

 

Yep. They probably tried to screw them in using a flathead screwdriver. The chucked screw doesn't have that problem as long as you're not an idiot.

 

 

id look into this, and it seemed to me (visually) that with standard holes in a warmoth neck, they might be too close to the edge to use inserts. could be why they dont recomend. my notion was that on a non drilled neck you could simply move them inboard a little more.

 

but that was all guesswork on my part, i never go around to trying it yet.

[Angry Tele]

meh...If I were constantly taking the neck off Id consider it. Otherwise this fixes a problem that doesn't exist. As far as "much more better" well there are thousands of +50 year old Fenders that are still going strong. How long does this coupling have to last to be considered adequate? 100years? 1,000? 10,0000?

[MahaloVision]

 

after reading a few of the replys... some of you really need to watch what you say in these threads. Just posting to get you count up is really irresponsible. this is one of the most read guitar forums online. remember only a few people may post but you got a few hundred reading and saying" thats a good idea".

 

 

That's a fair point. My only defense is that I try to only post when it's something I've personally done, and I have installed threaded inserts in various places on guitars with good success. I've also split a heel off an acoustic guitar neck made of Padauk (one I made, so no huge problem) by installing a threaded insert improperly, which is why I've gone to knockdown bolts for those applications. But for cavity covers, it's nice to have those little #6 inserts for the screws.

[headless]

 

... which is why I've gone to knockdown bolts for those applications. But for cavity covers, it's nice to have those little #6 inserts for the screws.

 

 

You've mentioned these "Knockdown Bolts", and I looked them-up, but there seem to be various types of hardware in that catagory, and I'm not sure which you're speaking-of, or how they would be applied.

 

Could you clue-me in on these? Thanks.

[MahaloVision]

 

Could you clue-me in on these?

 

 

Sure thing. This link should explain it well enough.

[Wyatt]

 

Seems like a lot of work for only a small increase in tone. It makes sense if you're taking the neck off a lot, but I don't think there's a big chance of stripping out those holes if you're careful. Besides, repairing a stripped out hole is a very easy fix.

 

 

Poeple don't do the mod for tone. At least no one I've talked to.

 

It's actually a common mod for people who like to take their necks off of a guitar for travel on airplanes, Danny Gatton and Bill Kirchen are two I can think off that popularized the trend (thanks to Vintique).

 

Usually it's done of Tele's, Strat trem's all too much complexity in reassmbling and setting up to bother removing the neck to travel.

[JimboJ]

Whats the difference between screwing threaded inserts into the wood vs. screws into the wood? Aren't they both essetially screws? The only advantage I can see to the inserts is if you remove the neck often. But who does that?

[headless]

 

... The only advantage I can see to the inserts is if you remove the neck often. But who does that?

 

 

 

Guilty as charged.

 

I'm a tinker-er, and the necks come off for all sorts of reasons. I hate it when the wood-screws end-up stripping the holes in the neck.

 

This mod had given me the confidence that the next time I want to do some work, I won't have to deal with stripped neck screw holes.

 

I'm thinking that perhaps the strap-button screws might be another application for these inserts.

 

Think that'll effect that guitar's tone???

[Ratae Corieltauvorum]

 

except it is certainly no more difficult to put the threaded insrts in than to drill out and glue dowells in and redrill.

 

 

Added to the fact that dowel's grain goes the wrong way, although you could make your own across grain dowels at a push

[ihavenofish]

 

Whats the difference between screwing threaded inserts into the wood vs. screws into the wood? Aren't they both essetially screws? The only advantage I can see to the inserts is if you remove the neck often. But who does that?

 

 

depends on the insert. the ones ive used in furniture typically have a wider "blade" type thread with a shallow angle which will hold better than a normal wood screw of the same size. the also have less tendency to back out the way wood screws can on a neck - i tend to tighten the screws on my squier strat and duosonic once in a while from what i assume is humidity changes moving the screws.

 

the end user who doesnt tinker probably wont care as long as everythings working well. most of the proponents i see in this thread are people who either build from scratch, parts or do heavy modding. that probably tells you something right there.

[bvr775]

 

Added to the fact that dowel's grain goes the wrong way, although you could make your own across grain dowels at a push

 

 

a dowel pin has been proven time and time again to have greater holding strength than screwing striaght into wood. Think about the forces applied to the pin after you put a screw in it.the pin expands wedging itself into the wood and because of limited room for expansion it compresses tight against the screw.

now think about what happens when you run a screw cross grain. the wood splits down the grain and makes the screw much easier to pull out.

[bonaventura]

cool idea...

 

so now we can swicth necks often without compromising the joints.

 

mighty handy if someone is trying to figure out how a maple+rosewood sounds compare to an all maple neck or whatever combination neck.

 

with the same body material, construction, pups, pot values, cap values, grain direction, geographical position and all the other items purists might have to say with regards to tone, i'd say alot of factors are constant.

 

if anybody has done their research, pls share with us.

[ihavenofish]

 

a dowel pin has been proven time and time again to have greater holding strength than screwing striaght into wood. Think about the forces applied to the pin after you put a screw in it.the pin expands wedging itself into the wood and because of limited room for expansion it compresses tight against the screw. now think about what happens when you run a screw cross grain. the wood splits down the grain and makes the screw much easier to pull out.

 

 

screwing into end grain is always the weakest possible wood joint.