mistermikev Posted October 20, 2020 Report Share Posted October 20, 2020 so was reading this thread over at talkbass and thought many here would find it a valuable resource...I see a lot of great applications for this... esp the idea that you can make a much smaller grove for neck reinforcement and not have to worry at all about a tight fit between carbon fibre rod and slot... https://www.talkbass.com/threads/less-expensive-carbon-fiber-reinforcement.1287574/#post-20099564 the jist is: you buy 6K TOW carbin fibre thread, cut a slot... fill it with thread... then fill with epoxy. def going to use this on upcoming basses. Quote Link to comment Share on other sites More sharing options...
curtisa Posted October 20, 2020 Report Share Posted October 20, 2020 Don't the carbon fibre strands need to be held under tension while the epoxy sets in order to gain the required strength? I'm not sure you can just lay the fibre strands in the slot, pour epoxy over it and end up with stiffened rod. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 20, 2020 Author Report Share Posted October 20, 2020 4 hours ago, curtisa said: Don't the carbon fibre strands need to be held under tension while the epoxy sets in order to gain the required strength? I'm not sure you can just lay the fibre strands in the slot, pour epoxy over it and end up with stiffened rod. well, not according to bruce. I imagine that could certainly improve it. that said... once the epoxy dries... the epoxy would be working with the carbon fibre. as I understand the carbon fiber has pull strength... and the epoxy has sticking strength... so the epoxy is essentially holding the fibre to each mm of space... and the carbon fibre's pull strength would be engaged by a bend. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 20, 2020 Author Report Share Posted October 20, 2020 fascinating... it's a good question curtisa... and as a result I have been reading some more threads... here's bruce putting it to work... https://www.talkbass.com/threads/my-les-paul-bass-build-i-need-a-gibby-too.1120298/page-25#post-17990278 I suppose... the way he is sandwiching it in there... doesn't pull the carbon taught... but def is putting some pressure on it. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 20, 2020 Author Report Share Posted October 20, 2020 and then my wife wondering why I'm watching videos about fishing rod production... https://www.google.com/search?client=firefox-b-1-d&q=making+carbin+fibre+rods#kpvalbx=_1NGOX4yvDI75-wT1vpiYBQ13 Quote Link to comment Share on other sites More sharing options...
curtisa Posted October 20, 2020 Report Share Posted October 20, 2020 10 hours ago, mistermikev said: well, not according to bruce. I imagine that could certainly improve it. that said... once the epoxy dries... the epoxy would be working with the carbon fibre. as I understand the carbon fiber has pull strength... and the epoxy has sticking strength... so the epoxy is essentially holding the fibre to each mm of space... and the carbon fibre's pull strength would be engaged by a bend. Dunno. Would the epoxy/carbon mix gain any more strength if the material being impregnated into the channel was something else just as pliable? Cotton rope? Nylon? Horse hair? I'm not suggesting the process doesn't add stiffness to a neck, but I'm doubtful that two epoxied-in carbon fibre strand/channels would be more effective than epoxying in a couple of 6mm premade carbon fibre bars either side of the trussrod. The example that Bruce demonstrates in the linked thread only has the fibre laid about two thirds the length of the neck, directly underneath the trussrod. Is it stiffer than the amount of timber he removed to make room for the carbon fibre strands and epoxy? Probably. Is it improving things in a measurable way? I'm not sure. The skeptic in me wants to say that with the amount of carbon fibre and epoxy he's added to that neck the trussrod is still doing 95% of the work in keeping it stable. 3 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 20, 2020 Author Report Share Posted October 20, 2020 1 hour ago, curtisa said: Dunno. Would the epoxy/carbon mix gain any more strength if the material being impregnated into the channel was something else just as pliable? Cotton rope? Nylon? Horse hair? I'm not suggesting the process doesn't add stiffness to a neck, but I'm doubtful that two epoxied-in carbon fibre strand/channels would be more effective than epoxying in a couple of 6mm premade carbon fiber bars either side of the trussrod. The example that Bruce demonstrates in the linked thread only has the fibre laid about two thirds the length of the neck, directly underneath the trussrod. Is it stiffer than the amount of timber he removed to make room for the carbon fiber strands and epoxy? Probably. Is it improving things in a measurable way? I'm not sure. The skeptic in me wants to say that with the amount of carbon fibre and epoxy he's added to that neck the trussrod is still doing 95% of the work in keeping it stable. well... as I understand it... the carbon fiber rods you get are not pure carbon fiber. Bruce explained in that thread that they were (allegedly) similar carbon fiber fillaments encased in what I thought he said was a polyester resin? so... in effect... his argument was that the carbon fiber rods you buy are adding in a bunch of plastic to your neck. He also argued that the typical carbon fiber rod is is much bigger than you even need. he said he adds between 2-12 strands of that TOW and that is enough. The benefit being that you can place the carbon fiber below your truss rod where it actually benefits the neck strength more as it's closer to the back of the neck... and you can use a very thin layer of it and very little epoxy... and according to him, that is enough to make his necks quite rigid. Half the reason I posted it here... was to see what you guys thought. Like you, I had the very sm questions "how could some carbon fiber thread possibly reinforce the neck?" While he sites that he has done vast testing privately and for commercial builders... I see no evidence. the only thing that I can offer is that bruce is (apparently) quite popular at talkbass and does neck builds commercially for a number of builders (who... i dunno). The number of 5 and 6 string bass builders on that site that acknowledged/sited him as credible made me think that perhaps he's on to something. that's enough to pique my interest. what we need now is a way to test this. so... assuming I go out and buy some carbon fiber tow thread at some point... and some west systems epoxy... what? make a little cardboard trough and put some strands in it and pour in epoxy and compare the strength of that to another trough that I just fill with epoxy and say... nylon string? also, just wanted to mention... the primary benefit/goal of bruces' method was that you can get 1000 ft of this fillament for $30. ie... it's not only potentially better, but it's much cheaper. so for $30 if you do 12 4' strands per guitar... you can do 20 guitars. all that said... in the process saw two different inexpensive places to buy carbon fiber rods... https://www.racedayquads.com/products/1-meter-carbon-fiber-rod-1pc-choose-your-size?variant=31470540292209&gclid=EAIaIQobChMI_dqLyZvE7AIVfCCtBh2JCAnNEAQYBSABEgJt3_D_BwE https://dragonplate.com/carbon-fiber-rod also... in watching the fishing rods being made... they literally take carbon fiber fabric... wrap it around a metal rod... then heat it... then pull out the metal rod and you have a fishing pole. what does this mean? i dunno... but fishing poles are incredibly strong... I always thought they were solid on the inside... but apparently they are completely hollow. in the process you see this limp fabric rolled around a rod become a fishing pole. Quote Link to comment Share on other sites More sharing options...
curtisa Posted October 20, 2020 Report Share Posted October 20, 2020 57 minutes ago, mistermikev said: well... as I understand it... the carbon fiber rods you get are not pure carbon fiber. Bruce explained in that thread that they were (allegedly) similar carbon fiber fillaments encased in what I thought he said was a polyester resin? Yep - I understand how the rods are made, but the key thing that (to my feeble mind) makes the difference is that the strands of carbon fibre are pulled taut as they are fed through the resin casting process. Bruce's method lays a few strands loosely into the channel and burys them in epoxy. For all I know his method does exactly what he claims it does, but I have questions regarding the effectiveness of it compared to just spending a few bucks extra per build in raw materials and buying a rod. 1 hour ago, mistermikev said: i dunno... but fishing poles are incredibly strong... I always thought they were solid on the inside... but apparently they are completely hollow. in the process you see this limp fabric rolled around a rod become a fishing pole. But they are designed to flex without breaking. Doesn't that imply that the marrying of the (relatively) loose wrapping of carbon fibre weave and epoxy allows some degree of compliance in the tube? Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 21, 2020 Author Report Share Posted October 21, 2020 59 minutes ago, curtisa said: Yep - I understand how the rods are made, but the key thing that (to my feeble mind) makes the difference is that the strands of carbon fibre are pulled taut as they are fed through the resin casting process. Bruce's method lays a few strands loosely into the channel and burys them in epoxy. For all I know his method does exactly what he claims it does, but I have questions regarding the effectiveness of it compared to just spending a few bucks extra per build in raw materials and buying a rod. But they are designed to flex without breaking. Doesn't that imply that the marrying of the (relatively) loose wrapping of carbon fibre weave and epoxy allows some degree of compliance in the tube? you know it's hard to argue with that reason. I didn't know they actually pull them taut when they make them. hmm... kind of changes my mind on it - thank you for that. over at racedayquads you can get little tiny cones (possibly single strand?) that would kind of give me the same possibility for using less of it and yet adding rigidity. afa rods... well... yes. but we don't really want perfectly rigid and we don't want super bendy. are they more flexible than maple - yes. is it more rigid than a hollow maple cone of the same size? I would guess yes. before you ask "bendy" is a technical term we use in the engineering industry. In laymans terms it means plyable. I hate to use fancy and all but sometimes I accidentally slip into engineering mode and can't help it (heheh) Quote Link to comment Share on other sites More sharing options...
curtisa Posted October 21, 2020 Report Share Posted October 21, 2020 5 minutes ago, mistermikev said: I didn't know they actually pull them taut when they make them Maybe 'taut' isn't the right word, but they're definitely under some tension as they're fed through the moulds (it's called 'pultrusion' after all - the strands get pulled through the resin casting process). It'd be an interesting experiment to try at the very least - form a 4' long beam of epoxy and carbon fibre strands and compare it to a premade carbon fibre beam of the same length and cross sectional area. If they have equal performance when attempting to bend them in the same fashion as they'd undergo inside a neck, then you have your answer Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 21, 2020 Author Report Share Posted October 21, 2020 Just now, curtisa said: Maybe 'taut' isn't the right word, but they're definitely under some tension as they're fed through the moulds (it's called 'pultrusion' after all - the strands get pulled through the resin casting process). It'd be an interesting experiment to try at the very least - form a 4' long beam of epoxy and carbon fibre strands and compare it to a premade carbon fibre beam of the same length and cross sectional area. If they have equal performance when attempting to bend them in the same fashion as they'd undergo inside a neck, then you have your answer right on. there's pulling and there's pulling. I guess it all boils down to what sort of tension is involved in pulltrusion of their product. I think an experiment would be pretty cool... putting that on my 'when I have time' list. could just use a similar weight and measure the amount of 'bendiness' - awe there I go again (hehe). I was thinking I might ask bruce if he has any documentation but I don't want to insult (like who am I asking him to prove it). did a little searching to see if I could find any such tests but no luck. at the very least... we come out of this with a conversation I enjoyed quite a bit. at most, I'm going to snag some of these materials and try it at some point. will def share the results. Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted October 21, 2020 Report Share Posted October 21, 2020 8 hours ago, mistermikev said: what we need now is a way to test this. so... assuming I go out and buy some carbon fiber tow thread at some point... and some west systems epoxy... what? make a little cardboard trough and put some strands in it and pour in epoxy and compare the strength of that to another trough that I just fill with epoxy and say... nylon string? This is starting to sound more interesting than it first looked. It also challenged my brain to think about the logic... Correct me if I'm wrong in the following: Carbon fibre doesn't stretch much Carbon fibre is coarse so the resin can stick to it (a nylon string is slippery as Teflon) Resin is more flexible than carbon fibre Resin, even hardened, is basically liquid so it doesn't compress Both resin and carbon fibre bend When carbon fibre is molded inside resin, two things happen: The carbon fibre prevents the resin from stretching (a nylon string might just slide) similarly to a single action truss rod The resin prevents the carbon fibre from crimping similarly to the neck around a single action truss rod. So the fibre keeps pulling and the resin keeps pushing and the result is stiffness. 1 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 21, 2020 Author Report Share Posted October 21, 2020 3 hours ago, Bizman62 said: This is starting to sound more interesting than it first looked. It also challenged my brain to think about the logic... Correct me if I'm wrong in the following: Carbon fibre doesn't stretch much Carbon fibre is coarse so the resin can stick to it (a nylon string is slippery as Teflon) Resin is more flexible than carbon fibre Resin, even hardened, is basically liquid so it doesn't compress Both resin and carbon fibre bend When carbon fibre is molded inside resin, two things happen: The carbon fibre prevents the resin from stretching (a nylon string might just slide) similarly to a single action truss rod The resin prevents the carbon fibre from crimping similarly to the neck around a single action truss rod. So the fibre keeps pulling and the resin keeps pushing and the result is stiffness. as it was described in the thread... it works a lot like concrete with rebar inside it. The two separated have very dif properties than the two together. rebar is in fact fairly easy to bend... concrete is fairly brittle. reinforced concrete is fairly resistant to both. to some degree... by pushing down on the carbon fiber with the filler block, and assuming you laid the strands in there straight, you would be sort of making it taut. as curtisa said, there's little doubt it would add some amount of stiffness but is that equiv of the stiffness achieved by the pulltrusion process? only one way to find out. Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted October 21, 2020 Report Share Posted October 21, 2020 35 minutes ago, mistermikev said: as it was described in the thread... it works a lot like concrete with rebar inside it. Oh, that slipped my eye. But yes, same thing. As for using nylon string, knots at the ends would eliminate the slipping issue. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 21, 2020 Author Report Share Posted October 21, 2020 5 minutes ago, Bizman62 said: Oh, that slipped my eye. But yes, same thing. As for using nylon string, knots at the ends would eliminate the slipping issue. well, I think @curtisa's point about comparing to mfg carbon rods makes more sense... after all that is the thing we are really interested in the comparison to. Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted October 21, 2020 Report Share Posted October 21, 2020 Hehe, just imagine filling a slot in the guitar neck with rebar and concrete... 1 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 21, 2020 Author Report Share Posted October 21, 2020 Just now, Bizman62 said: Hehe, just imagine filling a slot in the guitar neck with rebar and concrete... that WOULD stiffen it. Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted October 21, 2020 Report Share Posted October 21, 2020 Should the few last comments in this thread be teared off the context our wives might roll their eyes. Wut? Hubby wants aletrnatives for a stiff rod, huh? Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 21, 2020 Author Report Share Posted October 21, 2020 Just now, Bizman62 said: Should the few last comments in this thread be teared off the context our wives might roll their eyes. Wut? Hubby wants aletrnatives for a stiff rod, huh? omg... well on that note... yesterday she comes in and I'm watching fishing rod videos while I'm also watching the song 'fish on' by ramstein. someone at talkbass referenced that song and I never heard it before and I'm blushing even now thinking of the lyrics. she gave me an odd look. highly recommend you go listen to that song! Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted October 21, 2020 Report Share Posted October 21, 2020 Found it, listened to it and even read the lyrics. The video was hilarious, making the women produce electricity for the band with the stationary bikes reminded me of medieval organs like the ones in the Winchester Cathedral: Two organists to play and 70 men to operate the 26 bellows! 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 21, 2020 Report Share Posted October 21, 2020 You need to consider the epoxy as well. Epoxy resin that is for carbon fiber is different than the stuff you can but at the hardware store. It is a resin designed to be heat cured to its hardness where most utility epoxy is much softer and totally relies on a chemical reaction only and is for bonding use. I have friends that build things for Government Helicopters from carbon fiber as well as carbon fiber spinners for racing airplanes. It is a whole different beast when it comes to how strength is introduced via epoxy resins, heat and carbon fiber type in regards to how it is laid up. .MK Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 21, 2020 Author Report Share Posted October 21, 2020 30 minutes ago, MiKro said: You need to consider the epoxy as well. Epoxy resin that is for carbon fiber is different than the stuff you can but at the hardware store. It is a resin designed to be heat cured to its hardness where most utility epoxy is much softer and totally relies on a chemical reaction only and is for bonding use. I have friends that build things for Government Helicopters from carbon fiber as well as carbon fiber spinners for racing airplanes. It is a whole different beast when it comes to how strength is introduced via epoxy resins, heat and carbon fiber type in regards to how it is laid up. .MK interesting... it kind of goes along with what I was seeing on the fishing poles. they put them in a heater, and afterwards they are 'bonded'. Not sure that would be possible as a consumer but... all that said I would still be curious of what sort of results you could get. actually, if the carbon strands are 70% as effective as the commercially available rods it'd be worth it. I could see multiple applications (inlay carbon fiber strings on as runners on the back of a neck). further, parker fly used carbon fiber on the outside of wood no? Did they use heat? My gut would guess no as that might cause issues with the wood, but I honestly done know. if they didn't use heat... what sort of resin where they using? 1 Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted October 21, 2020 Report Share Posted October 21, 2020 Heat or no heat? I guess we're starting to talk about fine tuning. Would stainless steel and ancient Roman concrete be better than rebar and modern concrete? (yes it would, just because Roman concrete is still strong after 2000 years and modern concrete only lasts about 50 years. Very poor comparison...) 1 Quote Link to comment Share on other sites More sharing options...
Prostheta Posted October 21, 2020 Report Share Posted October 21, 2020 6 hours ago, mistermikev said: omg... well on that note... yesterday she comes in and I'm watching fishing rod videos while I'm also watching the song 'fish on' by ramstein. someone at talkbass referenced that song and I never heard it before and I'm blushing even now thinking of the lyrics. she gave me an odd look. highly recommend you go listen to that song! You mean Lindemann, surely? Till's side project is entirely separate in both theme and lineup! To be fair, my own personal taste in NDH is Eisbrecher. Then again, I did grow up with bands like Die Krupps in my regular playlists. 1 Quote Link to comment Share on other sites More sharing options...
mistermikev Posted October 21, 2020 Author Report Share Posted October 21, 2020 1 hour ago, Prostheta said: You mean Lindemann, surely? Till's side project is entirely separate in both theme and lineup! To be fair, my own personal taste in NDH is Eisbrecher. Then again, I did grow up with bands like Die Krupps in my regular playlists. When I 1st heard of this song I had no idea who Lindemann was. And I thought that sounds an awful lot like Rammstein then I looked it up and find out it was the dude for rom steed so forgive my confusion Quote Link to comment Share on other sites More sharing options...
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