# Aluminium neck reinforcement - Has anyone ever done it?



## Navid (Feb 6, 2013)

Hello,

I have an aluminium industry close to my house and they produce a lot of 6mm square section aluminium bars and I can get them for free.

Has anyone ever used aluminium as neck reinforcement?
I'm speaking of aluminium 7075


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## teleofseven (Feb 6, 2013)

Navid said:


> Hello,
> 
> I have an aluminium industry close to my house and they produce a lot of 6mm square section aluminium bars and I can get them for free.
> 
> ...



i've heard of aluminum necks but not reinforcement rods.

usually people use steel or carbon fiber. 

carbon fiber is super strong, and stiff.
steel is that too but some say more resonant of the two.

i would imagine aluminum being both less resonant and strong. it also reacts to temperatures alot more easier. it bends very easily too.

so i wouldn't see it as a fitting reinforcement material. 

go for steel, it's cheap!


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## Walterson (Feb 6, 2013)

teleofseven said:


> i've heard of aluminum necks but not reinforcement rods.
> 
> usually people use steel or carbon fiber.
> 
> ...



Steel is to heavy imho and why do you want a neck reinforcement to resonate?  Do you want some deadspots? Thats what happens when a neck resonates! The neck should be as stiff as possible and not wobble around....


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## VigierUSA (Feb 6, 2013)

Aluminum shrinks in the cold... The guitarist in my band has a guitar from the Electrical Guitar Company. It's entirely Aluminum. The neck never flexes, but it shrinks. In fact, when it's super cold he goes exactly one half step flat. After it warms up, it's totally fine, but that may be why it isn't used as often.


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## Navid (Feb 6, 2013)

Yeah I know about the fully aluminium guitars or necks.
I'm talking about aluminium alloys 7075 and 2021, they are aerospace alloys, strong and do not move much.
Aluminium alloy 7075 are supposed to be even stronger than some steel.
Well, I guess i'll just try and see what happens. Pics coming soon.


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## Transmissions (Feb 6, 2013)

I don't think you want to get aluminum reinforcement. 
A lot of the aluminum necked guitars which were made so that they didnt bend, and could eliminate the problem of warping etc, ended up bending. 
How would you even put it on the neck of your guitar other than gluing it on the back? If you were going to somehow put it under the fret board wouldnt it be better to get a stronger truss rod?


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## ElRay (Feb 6, 2013)

It's been done: Guitar Neck Build - Rick Toone | Luthier

But Rick Toone stopped selling the "TOONE & TOWNSEND Neck Core&#8482;" and it looks like the page was taken down.

Ray


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## Navid (Feb 6, 2013)

ElRay said:


> It's been done: Guitar Neck Build - Rick Toone | Luthier
> 
> But Rick Toone stopped selling the "TOONE & TOWNSEND Neck Core" and it looks like the page was taken down.
> 
> Ray



Thats interesting, I shall email mr. Toone and ask him about his experience.


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## AwDeOh (Feb 6, 2013)

Saw this when I was looking around for ideas on a Dupli-Carver:

Gemini Carbon Fiber D-Tube Guitar Neck Stiffener - Guitar Neck Reinforcement & Stabilization


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## vansinn (Feb 6, 2013)

Navid said:


> Thats interesting, I shall email mr. Toone and ask him about his experience.



Do note that Toone's aluminum insert isn't just for strength, but also very much for controlling unwanted vibrations in the neck; hence the fairly large slab.
Somewhere on his pages there is an in-depth analysis of how his insert works.

WRT how aluminum may work with temperatures, this is very dependent of which type.
I've never worked on series 7000, so can't say, but I do envy you for having access to those for free 

I would say unless you have special requirements for this particular instrument, carbon fiber inserts are more likely to give you added strength without _maybe_ affecting tone, while an aluminum insert _might_ result in more sustain, due to reducing excess vibrations in the neck.


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## Navid (Feb 7, 2013)

vansinn said:


> I would say unless you have special requirements for this particular instrument...



My special requirement is not end up broke  CF rods are very expensive. It is cheaper to just put 2 adjustable truss rods.


The tone related issue isn't a problem. I don't want to start wood/tone discussions, I'll just say I've never built a bad sounding guitar, even with oak necks.

I am planning to put 4 bars + double action truss rod. If it is true that aluminium 7075 moves much with warm weather, the neck will crack somewhere. Unless it doesn't really matter. How much could a 500x6x6mm piece really expand with 30 degrees difference? More or less than steel truss rods? If all the strength double action truss rods apply on the wood, the wood doesnt crack, would it crack with a little bit of expansion from these rods?
Since I do not have time to read and calculate, practical tests are my choice : P

The piece toone put inside is much larger than these rods, if it didn't expand enough to brutally destroy his necks, I'm positive these bars will do.


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## Necromagnon (Feb 7, 2013)

Thermal expension stays, imo, a marginal deformation. On a 6*6 mm section, with 30K difference, I'd say the rod may increase from something like 0.05% maybe? I really don't know, but I'm sure you can find the thermal expansion coefficient of the al on the web. Then, you'll know precisely. But I think it won't be really a problem. Also, I'm not sure your rods while suffer 30K temperature gradient. There's not mayne chance you play your guitar in a fridge, I think. Some, let's say it will be in home or concert hall and stuff, so around 15° mini, and during summer, let's go for 35°. As the rods are inside the neck, I'm note sure they will be at the ambiant temperature, so if they suffer at least a difference of 18/20K, it's quite the max imo.

I'm not familiar with thermomechanics (while I shoudl... :/ ), but I'm not sure this will be a huge problem here. And also, I think that with a 20K gradient, the neck will move more than the aluminum rods. 
PS: by "neck", I meant "wood".

Transmissions: you're such an awesome troll.


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## Navid (Feb 7, 2013)

Necromagnon said:


> Transmissions: you're such an awesome troll.



Dude btw your build is turning out awesome.


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## Necromagnon (Feb 7, 2013)

Navid said:


> Dude btw your build is turning out awesome.


The Nephilim? Unfortunately, I'm out for 7 months in Czech Rep, so I could not work on it (and I will have to rebuild the JP, it has major issues :/ ), but I hope to finish it quickly, I've many projects wainting...
Thx, btw.


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## vansinn (Feb 7, 2013)

Necromagnon said:


> Thermal expension stays, imo, a marginal deformation. On a 6*6 mm section, with 30K difference, I'd say the rod may increase from something like 0.05% maybe? I really don't know, but I'm sure you can find the thermal expansion coefficient of the al on the web. Then, you'll know precisely. But I think it won't be really a problem. Also, I'm not sure your rods while suffer 30K temperature gradient. There's not mayne chance you play your guitar in a fridge, I think. Some, let's say it will be in home or concert hall and stuff, so around 15° mini, and during summer, let's go for 35°. As the rods are inside the neck, I'm note sure they will be at the ambiant temperature, so if they suffer at least a difference of 18/20K, it's quite the max imo.
> 
> I'm not familiar with thermomechanics (while I shoudl... :/ ), but I'm not sure this will be a huge problem here. And also, I think that with a 20K gradient, the neck will move more than the aluminum rods.
> PS: by "neck", I meant "wood".



I'd tend to agree. Whatever.. expansion/deformation gradients can probably easily be found on places like wikipedia or from the manufacturer - hehe, the alu-processing plant near your house should be able to tell you about this 
Also, even if the aluminum does expand/contract, the wood will likely 'follow' the same expansions to some degree, so I think the problem is being overdramatized. And, it's not like we're approaching space sciences like an SR71 leaking fuel until flying at 120000ft at high temperatures making it expand to stop leaking


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## Necromagnon (Feb 7, 2013)

vansinn said:


> I'd tend to agree. Whatever.. expansion/deformation gradients can probably easily be found on places like wikipedia or from the manufacturer - hehe, the alu-processing plant near your house should be able to tell you about this
> Also, even if the aluminum does expand/contract, the wood will likely 'follow' the same expansions to some degree, so I think the problem is being overdramatized. And, it's not like we're approaching space sciences like an SR71 leaking fuel until flying at 120000ft at high temperatures making it expand to stop leaking


Absolutely.
The tension involved is not incredible also. I think that, what could be nice is to do Some kind of T shape with the fretboard being the horizontal top of the T. Then, to fill the gap and have something more common in shape to be playable, using something very light weight, as it won't play a part in the whole resistance.

I'm quite sure there were some stuffs like that in the 80', but I can't remember what...


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## Navid (Feb 7, 2013)

Necromagnon said:


> Absolutely.
> The tension involved is not incredible also. I think that, what could be nice is to do Some kind of T shape with the fretboard being the horizontal top of the T. Then, to fill the gap and have something more common in shape to be playable, using something very light weight, as it won't play a part in the whole resistance.
> 
> I'm quite sure there were some stuffs like that in the 80', but I can't remember what...



This T idea is cool, What about not filling the gap but routing the wood to fit?

...Next build, next build...


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## Necromagnon (Feb 7, 2013)

Navid said:


> This T idea is cool, What about not filling the gap but routing the wood to fit?
> 
> ...Next build, next build...


Yes. The idea is not mine, I've to highlight it, but a friend's on the french forum that suggested it for another luthier that is trying to make a light weight bass.
Routing the wood is, if I understand well, a bit more constraining for the size of T (there most be enough material on the bot end of the T channel, and also on the side), so is the bending resistance. But that could work also... I'll do a simple simulation tomorrow to check this out.


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## Pikka Bird (Feb 15, 2013)

Just a quick idea:







The red represents something like this:






...good idea/shitty idea?


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## Necromagnon (Feb 15, 2013)

hm... not bad at all, I guess... hm...

Yep, not bad, not bad... Need someone who devote to try it!


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## Pikka Bird (Feb 15, 2013)

^Well, I am already in the process of trying alternative things with a guitar I'm building. The body is an Ikea Lagan tabletop (damned hard, could barely get my saw through it), a hardwood fence post ripped in three with the center flipped will be a through-neck and I think I'll try teak as a fretboard wood. I might as well try these aluminium thingies too. 

Shouldn't be too hard to put a channel in the left and right neck laminations and epoxy the aluminium to that before gluing the lams together.


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## OfArtAndArsenal (Feb 15, 2013)

That's a good idea! I was thinking of building one out of an old frying pan and using a dead cat I found for the neck (that rigor is really strong), but I like your secondhand materials better...

No seriously, I think repurposing is awesome. Can't wait to see how it turns out man.


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## Navid (Feb 15, 2013)

OfArtAndArsenal said:


> and using a dead cat I found for the neck



I've tried with a live cat but it used to bite me while sliding


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## Thrashmanzac (Feb 15, 2013)

Pikka Bird said:


> Just a quick idea:
> 
> 
> 
> ...



bad idea. you would be better off using just a straight "I" beam of aluminium, as the top of the "L" shape offers no real support to the neck. by that i mean it will make the neck stiffer on one plane, but the plane on witch you need the neck re-enforced for is the up and down movement, not side to side. if that makes sense?


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## Navid (Feb 15, 2013)

Thrashmanzac said:


> bad idea. you would be better off using just a straight "I" beam of aluminium, as the top of the "L" shape offers no real support to the neck. by that i mean it will make the neck stiffer on one plane, but the plane on witch you need the neck re-enforced for is the up and down movement, not side to side. if that makes sense?



Why would one not need the reinforcement in the back-forward dimension?
An L piece of aluminium is stiffer than 1 single straight piece. We're talking of the 3D world, not the 2D linear one, forces are never applied in perpendicular directions, especially in a round piece of wood (neck shape)


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## Thrashmanzac (Feb 15, 2013)

fair point


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## Pikka Bird (Feb 15, 2013)

Thrashmanzac said:


> bad idea. you would be better off using just a straight "I" beam of aluminium, as the top of the "L" shape offers no real support to the neck. by that i mean it will make the neck stiffer on one plane, but the plane on witch you need the neck re-enforced for is the up and down movement, not side to side. if that makes sense?



Well, I see your point, but as long as the channel is tight and the right angle shape isn't allowed to flex then it'll keep extremely stable in both directions. The vertical side will keep it from bending back and forth, and the horizontal will add side-to-side stability (not that it's often needed, though)

...I think I'm gonna do the "stand on the neck" test eventually when I'm close to completion... If I have the nerve.


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## Necromagnon (Feb 15, 2013)

Thrash: yep, you're right. But using an I that as the same height or the L will make no difference in terms of back and forth resistance (direction of the common bow). So if we can use something that will help in some other directions, it's not loss.

But in the theory, you're completely right.


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## Navid (Feb 15, 2013)

Pikka Bird said:


> ...I think I'm gonna do the "stand on the neck" test eventually:



Holy fucking shit. Please get somebody to film you


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## SkullCrusher (Feb 15, 2013)

Aluminium is not that strong. It's quite soft.

You want something stiff and hard.

Vigier had the correct idea with carbon fibre


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## Kroaton (Feb 15, 2013)

It's not your average aluminium. It's 7075 aircraft grade , (aluminium-zinc-magnesium-copper alloy)

You will have to figure out what the temper of it is to figure out exactly how strong it is and what heat tolerance it has.


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## Navid (Feb 15, 2013)

Kroaton said:


> It's not your average aluminium. It's 7075 aircraft grade , (aluminium-zinc-magnesium-copper alloy)
> 
> You will have to figure out what the temper of it is to figure out exactly how strong it is and what heat tolerance it has.



T6
Damn you're well informed


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## Necromagnon (Feb 15, 2013)

What's said above.
And also:


SkullCrusher said:


> Vigier had the correct idea with carbon fibre


Carbon fiber can be much less resistant than steel.
Also, up to now, the highest elastic stress I've seen is nickel-titanium alloys (I'm working with it): 2 GPa and goes back with less than 0.01% of plastic strain... 

(yes, absolutely no relation with the conversation but I needed to put my 2 cents science in here  )


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## Kroaton (Feb 15, 2013)

Navid said:


> T6
> Damn you're well informed



I've been planning my first guitar build (8 string , semi-fretless) for a few months now and I've been researching neck reinforcement techniques and alternative body/neck materials.

Aircraft grade aluminium is a fine choice as an alternative to carbon fiber bars for neck reinforcement.

For those wondering about the economic feasibility of using them , you can buy a round rod or flat bar depending on what you want for somewhere between 12-20$.
Not that pricey seeing how you get a massive improvement in tuning stability from using them alongside a quality truss-rod.


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## vansinn (Mar 30, 2013)

Thrashmanzac said:


> bad idea. you would be better off using just a straight "I" beam of aluminium, as the top of the "L" shape offers no real support to the neck. by that i mean it will make the neck stiffer on one plane, but the plane on witch you need the neck re-enforced for is the up and down movement, not side to side. if that makes sense?



I don't think it's a bad idea per se, though I do believe that the L shaped profiles usually available aren't made from sufficiently strong alloys, probably less than series 4000.
Coupled with their usual dimensions, i.e. usually being fairly thin-walled, I have the feeling they won't add too much stiffness in either directions.

I think the I beams found in hobby stores for those making their own electric hobby railways just might make for more stiffness 
Unless using at least series 6000 aluminum, I'd choose carbon profiles, though..


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## Navid (Mar 30, 2013)

vansinn said:


> I don't think it's a bad idea per se, though I do believe that the L shaped profiles usually available aren't made from sufficiently strong alloys, probably less than series 4000.
> Coupled with their usual dimensions, i.e. usually being fairly thin-walled, I have the feeling they won't add too much stiffness in either directions.
> 
> I think the I beams found in hobby stores for those making their own electric hobby railways just might make for more stiffness
> Unless using at least series 6000 aluminum, I'd choose carbon profiles, though..



I thought commercially available aluminium was all 6060 T6...
No, I don't often use aluminium 
Anyway, I can tell that if you ask nicely to large manufacturers they'd sell you a bar. In italy they don't sell them for cheap at all, they overcharge privates... (I asked every single manufacturer with a website)


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## SkullCrusher (Mar 30, 2013)

6082 is considered T6.

7075 is T7.

I would look at c250 gauge plate aluminium. (Very stable).

Although titanium or stainless steel would be better (303, 304 or 316).

Althought it adds much extra cost would be to professionally cut or machined.


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## Navid (Mar 31, 2013)

SkullCrusher said:


> Although titanium or stainless steel would be better (303, 304 or 316).
> 
> Althought it adds much extra cost would be to professionally cut or machined.



It also is quite heavier.
Anyway I've built a neck with the bars i talked about in this thread and it is doing good. I will update again in 10 years to discuss how it held twisting and relief...
To make it more interesting i've used beech wood.

Construction as following:
5 pieces beech
no scarf joint, angled headstock with volute
8 string 28'' scale 20mm thick at first fret, 22mm at XII fret.
1 dual action truss rod + 4 bars 6x6mm of aluminium 7075.

No pictures because my father stole my camera and left for mongolia/china/korea/thailand/bangladesh/sri lanka.
FML


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## Necromagnon (Mar 31, 2013)

Navid said:


> No pictures because my father stole my camera and left for mongolia/china/korea/thailand/bangladesh/sri lanka.



How I'm jalous of your father! 

Anyway, I really see no point of using titanium here, seriously. It's really too much. If you want to be sure that your Renault will take you to the ski station, you can put a V12 inside, sure. But I think it's a bit too much...
Titanium will cost you an arm, and the machining is strictly impossible without professional tools (I use Nickel-Titanium alloys, in wires of 0.1 mm diameter, and even this is not easy to cut without a freaking powerfull scissors).

Another question Navid: as we're not so far one from the other, do you have the supplier where you bought those bars? I'm interested.


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## Navid (Mar 31, 2013)

Necromagnon said:


> Another question Navid: as we're not so far one from the other, do you have the supplier where you bought those bars? I'm interested.



PMd


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## pondman (Mar 31, 2013)

I'm building two 8 strings and did a test run with Aluminium reinforcement rods on a few reject necks ( I've got lots of the stuff left over from a landscape project).

I tried various sizes and combinations and found it really had no strength and flexed more than the wood in some cases so went with the double truss rod set up.


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## Necromagnon (Mar 31, 2013)

pondman said:


> I tried various sizes and combinations and found it really had no strength and flexed more than the wood in some cases so went with the double truss rod set up.


Could we have more informations about that? I.e. aluminum grade, size of the bars, number, position, etc. ?
Could be really interesting for everyone.


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## Amanita (Mar 31, 2013)

80's stuff would be Kramer's basses and guitars. aluminium T cross section with 2 wooden fillets making up the neck profile. no truss rod. characteristic lyre-shaped headstocks.
haven't played one, but recordings i've heard done with them and people who had one in hands point to queer, "metallic" quality of sound.

speaking from experience with bicycle frames, 6xxx and 7xxx alu has excellent mechanical properties (higher modulus of elasticity than carbon/cro-mo steel actually) but they tend to age and loose properties with time when put under strain.


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