Less expensive carbon fiber reinforcement

[fenderfour]

I only found one passing mention of DragonPlate.com in the forum, so i thought I would share.

I'm starting my first build and found the prices for carbon reinforcement strips to be... excessive. I have gotten material from Dragon Plate for non-bass related projects. They have quality material and are responsive.

Website link: DragonPlate Carbon Fiber Composite Components - Carbon Fiber Sheets, carbon fiber tubes, carbon fiber structural, carbon fiber connectors, carbon fiber design

Neck Reinforcement strips: Invalid Link Removed

The .200 x .250 x 24" strip found elsewhere for $21.49 is only $8.81.

They do have a $30 minimum order. For $40 ish dollars I got two sets of neck reinforcement and a few other bits.

(I'm not in any way affiliated with, or paid by dragon plate, I'm just cheap)

 

[Gilmourisgod]

I've seen their site before but was put off by the minimum order. Now that I'm planning my second build with CF rods, wish I'd coughed up the $!

 

[Bruce Johnson]

The other alternative is to buy carbon fiber TOW (that's what it's called) instead. That's the bare carbon fiber stranding, which comes in a roll. I bought a roll of 6K TOW, about 5000', for $30 on ebay. That roll lasted me close to 20 years. I just recently opened a new roll.

You can use the TOW for all kinds of reinforcements in musical instruments. Basically, you set the raw stranding into a bed of hard epoxy. I use West Systems. You rout a slot in the wood, to any dimensions or configuration that you want. It can taper or even go around corners. Lay in the strands, as many as you want, and pour in the epoxy. You are effectively casting the "carbon fiber bar" in place.

The carbon fiber bars that you buy aren't solid carbon fiber. They are bundles of the TOW, which have been molded into rectangular bars with polyester resin, in a process called pultrusion. The result is similar to what I'm doing with the epoxy.

The TOW is available in different sizes; the common ones are called 4K, 6K and 12K. That refers to the number of individual strands of carbon fiber in the bundle. 6K TOW is 6,000 teensy little strands. If you twist it and pull it taught, 6K TOW is about 1/16" diameter. 12K TOW rolled up, is about 3/32" diameter.

In terms of strength, a single 6K bundle has a tensile strength roughly three times the same diameter steel piano wire. Reinforcing a bass neck, you really don't need very much. That's why I don't use the commercial bars. It's just putting big blocks of plastic in the neck. I can get all the necessary reinforcement from my own small cast-in-place bundle.

Anyway, that's an alternative to the bars. And it's much cheaper per neck. I typically put in 2-10 strands of 6K TOW; 4 to 20 feet from the roll.

 

[fenderfour]

The other alternative is to buy carbon fiber TOW (that's what it's called) instead. That's the bare carbon fiber stranding, which comes in a roll. I bought a roll of 6K TOW, about 5000', for $30 on ebay. That roll lasted me close to 20 years. I just recently opened a new roll.

You can use the TOW for all kinds of reinforcements in musical instruments. Basically, you set the raw stranding into a bed of hard epoxy. I use West Systems. You rout a slot in the wood, to any dimensions or configuration that you want. It can taper or even go around corners. Lay in the strands, as many as you want, and pour in the epoxy. You are effectively casting the "carbon fiber bar" in place.

The carbon fiber bars that you buy aren't solid carbon fiber. They are bundles of the TOW, which have been molded into rectangular bars with polyester resin, in a process called pultrusion. The result is similar to what I'm doing with the epoxy.

The TOW is available in different sizes; the common ones are called 4K, 6K and 12K. That refers to the number of individual strands of carbon fiber in the bundle. 6K TOW is 6,000 teensy little strands. If you twist it and pull it taught, 6K TOW is about 1/16" diameter. 12K TOW rolled up, is about 3/32" diameter.

In terms of strength, a single 6K bundle has a tensile strength roughly three times the same diameter steel piano wire. Reinforcing a bass neck, you really don't need very much. That's why I don't use the commercial bars. It's just putting big blocks of plastic in the neck. I can get all the necessary reinforcement from my own small cast-in-place bundle.

Anyway, that's an alternative to the bars. And it's much cheaper per neck. I typically put in 2-10 strands of 6K TOW; 4 to 20 feet from the roll.

That's a really great idea. Thanks! if I make a third bass I will get some TOW and try it out.

 

[rojo412]

The Dragon Plate rods that are the same dimensions as the Allparts rods cost $5.60 each.
Allparts sells them for $29 each.
I think I know where I'm getting CF rods from now on... THANKS!!!

 

[bdplaid]

The other alternative is to buy carbon fiber TOW (that's what it's called) instead. That's the bare carbon fiber stranding, which comes in a roll. I bought a roll of 6K TOW, about 5000', for $30 on ebay. That roll lasted me close to 20 years. I just recently opened a new roll.

You can use the TOW for all kinds of reinforcements in musical instruments. Basically, you set the raw stranding into a bed of hard epoxy. I use West Systems. You rout a slot in the wood, to any dimensions or configuration that you want. It can taper or even go around corners. Lay in the strands, as many as you want, and pour in the epoxy. You are effectively casting the "carbon fiber bar" in place.

The carbon fiber bars that you buy aren't solid carbon fiber. They are bundles of the TOW, which have been molded into rectangular bars with polyester resin, in a process called pultrusion. The result is similar to what I'm doing with the epoxy.

The TOW is available in different sizes; the common ones are called 4K, 6K and 12K. That refers to the number of individual strands of carbon fiber in the bundle. 6K TOW is 6,000 teensy little strands. If you twist it and pull it taught, 6K TOW is about 1/16" diameter. 12K TOW rolled up, is about 3/32" diameter.

In terms of strength, a single 6K bundle has a tensile strength roughly three times the same diameter steel piano wire. Reinforcing a bass neck, you really don't need very much. That's why I don't use the commercial bars. It's just putting big blocks of plastic in the neck. I can get all the necessary reinforcement from my own small cast-in-place bundle.

Anyway, that's an alternative to the bars. And it's much cheaper per neck. I typically put in 2-10 strands of 6K TOW; 4 to 20 feet from the roll.

Nice! But then I want to ask the question: what is the epoxy doing, and is that enough on its own?

 

[Engle]

Nice! But then I want to ask the question: what is the epoxy doing, and is that enough on its own?

It's holding the carbon fibre strands in place. Just like concrete is there to hold rebar in buildings.

 

[T_Bone_TL]

Carbon fiber (like rebar) has tensile strength (you can pull on it a lot before it breaks.) Epoxy (like concrete) has little tensile strength, but good compressive strength (and epoxy also sticks to other things well, moreso than concrete, so the analogy, which is quite good, starts to fray a tiny bit.) Things typically called just "fiberglass", "Carbon fiber" or "reinforced concrete" are composites of materials (fiberglass or carbon fibers with epoxy or other plastic resins - steel with concrete) which work better together than the individual components alone. So no, you don't want to cut a channel, fill it with epoxy, and call it reinforced - nor do you want to fill it with carbon fiber tow and no epoxy and call it reinforced.

 

[Bruce Johnson]

You guys beat me to it! Yeah, the epoxy attaches the carbon fiber to the wood, so the carbon fiber stranding can go to work restricting the movement of the wood.

When using the carbon fiber TOW like this in a neck, it's acting mostly like a tension cable. That's its most efficient use, because the carbon fibers are very stiff in the stretch direction. And the epoxy is really good at grabbing hold of the TOW, because it soaks in and bonds to all the individual fibers. Remember, one strand of TOW is 6,000 or 12,000 individual loose fibers, which adds up to a lot of surface area for the epoxy to bond to.

Now, a slot that's filled with carbon fiber TOW and epoxy is also pretty stiff in compression too. The TOW by itself would have almost no stiffness in compression, because it would be like pushing on a rope. Or pushing on 6000 teeny little threads. But when you surround it and saturate it with epoxy, it becomes a stiff column, and will take a lot of compression load.

 

[bdplaid]

It's holding the carbon fibre strands in place. Just like concrete is there to hold rebar in buildings.

Yes, I know that, my comment was related to what role does the epoxy itself play, in addition to the CF. In other words, is the epoxy in the channel enough on it's own to stiffen the neck? Just a thought.

 

[bdplaid]

I'm also wondering if you guys know - I'm sure it's been done - Has anyone made a neck with a layer of CF matte/fabric sandwiched between the neck and the fretboard? Seems like it might do the same thing as rods and be easier to do (no channels cut), although maybe more expensive.

 

[Bruce Johnson]

Yes, I know that, my comment was related to what role does the epoxy itself play, in addition to the CF. In other words, is the epoxy in the channel enough on it's own to stiffen the neck? Just a thought.

Basically, no. A routed channel filled with epoxy isn't going to be much stronger or stiffer than the wood you took out. Epoxy, by itself, is a relatively soft plastic. A slot full of epoxy would be about like fitting in a strip of Plexiglas. But epoxy is really good at sticking and saturating. Use epoxy to surround some other stiff material, like carbon fiber stranding, or fiberglass stranding, or a metal plate, and you've added some real strength and stiffness.

 

[T_Bone_TL]

I'm also wondering if you guys know - I'm sure it's been done - Has anyone made a neck with a layer of CF matte/fabric sandwiched between the neck and the fretboard? Seems like it might do the same thing as rods and be easier to do (no channels cut), although maybe more expensive.

Have not done, quite possibly someone has done, though I think it would be largely ineffective - it's physically in the wrong place - on the compression side of the "beam" that is the neck. Now, if you built a neck lamination sandwich that put it towards the back (or tension side) of the neck, that might work. Also, half the fibers in the fabric would be doing nada/zip/zilch for you as they'd be oriented side to side...

 

[Bruce Johnson]

I'm also wondering if you guys know - I'm sure it's been done - Has anyone made a neck with a layer of CF matte/fabric sandwiched between the neck and the fretboard? Seems like it might do the same thing as rods and be easier to do (no channels cut), although maybe more expensive.

Right idea, wrong direction. A thin sheet of carbon fiber matte saturated with epoxy, between the neck and the fingerboard, would have very high tensile strength. But it would provide almost no resistance to the bending (bowing) of the neck.

Turn it 90 degrees. Put the carbon fiber matte vertically between the laminate strips of the neck wood, and you'd have a really stiff, really stable neck.

 

[Roxbororob]

I have thought about (am planning to try) routing into an old (cheaper) neck from the back thinking this will get the tensioned strands closer to the farthest tensioned plane. Obvious problems might be tricky routing and covering up. Thoughts?

Edit: I have also thought about epoxy (or mechanical fastener) only at each end. In other words the bar unconstrained mid length.

 

[Bruce Johnson]

I have thought about (am planning to try) routing into an old (cheaper) neck from the back thinking this will get the tensioned strands closer to the farthest tensioned plane. Obvious problems might be tricky routing and covering up. Thoughts?

Absolutely. That's where the carbon fiber should be, to make the best use of it. A "skunk stripe" filled with carbon fiber TOW and epoxy is the most efficient way to reinforce a neck against bending. Back there, an 1/8" square slot filled with a single strand of 12K TOW would provide more reinforcement than one of those silly CF bars up under the fingerboard.

I make most of my necks using thin hidden channels of carbon fiber, way down deep, within 1/8" of the final back surface of the neck. I usually put it in from the top, in a deep slot under the truss rod, rather than from the bottom, under a skunk stripe. But it's the same idea: put the tensile reinforcement at the very back of the neck.

I've also installed the carbon fiber stranding in that location by routing small slots into the sides of the center neck lamination strip. That works too.

To add this kind of reinforcement to an existing commercial neck from the back, you have to be careful not to hit the truss rod (depending on what type it is). The best way would be to rout a pair of small slots down the back of the neck, on either side of the truss rod. Maybe 1/8" wide x 3/16" deep. That's all they need to be. Lay in some epoxy, a single strand of carbon fiber TOW, and a thin strip of some pretty looking wood to cover it. After it's dry, blend it in to the shape.

This technique of inserting carbon fiber stranding deep into the neck is also a good way to prevent the dreaded "ski jump" or "12th fret kink" problem. We've talked about this over on the big ski jump thread.

 

[bdplaid]

Right idea, wrong direction. A thin sheet of carbon fiber matte saturated with epoxy, between the neck and the fingerboard, would have very high tensile strength. But it would provide almost no resistance to the bending (bowing) of the neck.

Turn it 90 degrees. Put the carbon fiber matte vertically between the laminate strips of the neck wood, and you'd have a really stiff, really stable neck.

Got it. Thanks for the reply.

 

[bdplaid]

Absolutely. That's where the carbon fiber should be, to make the best use of it. A "skunk stripe" filled with carbon fiber TOW and epoxy is the most efficient way to reinforce a neck against bending. Back there, an 1/8" square slot filled with a single strand of 12K TOW would provide more reinforcement than one of those silly CF bars up under the fingerboard.

I make most of my necks using thin hidden channels of carbon fiber, way down deep, within 1/8" of the final back surface of the neck. I usually put it in from the top, in a deep slot under the truss rod, rather than from the bottom, under a skunk stripe. But it's the same idea: put the tensile reinforcement at the very back of the neck.

I've also installed the carbon fiber stranding in that location by routing small slots into the sides of the center neck lamination strip. That works too.

This technique of inserting carbon fiber stranding deep into the neck is also a good way to prevent the dreaded "ski jump" or "12th fret kink" problem. We've talked about this over on the big ski jump thread.

I wonder if this could be a fix for a neck one likes, but has a bad dead spot? I recently bought a Mexi jazz bass, it played like a dream and sounded great, but the dead spot was horrendous. Even the band noticed.

 

[Bruce Johnson]

I wonder if this could be a fix for a neck one likes, but has a bad dead spot? I recently bought a Mexi jazz bass, it played like a dream and sounded great, but the dead spot was horrendous. Even the band noticed.

Yes, that's one way to (potentially) fix a resonant dead spot. Stiffening the neck will change how the basses' frame resonates. It will move the dead spot up and probably reduce it. Hopefully out of the range where you notice it. But with frame resonances, it can be tricky to predict where it will end up.

 

[bdplaid]

You give me all kinds of ideas for ways to make sawdust and firewood from bass necks!