why carbonfiber?

[jtkwest]

why is carbon fiber cosidered so much better than other materials on small / lower power guns? what is the advantage for 90 and smaller euro guns especially? i know it is strong and reduces barrell flexing, but it is heavy ,even if it does float, it seems unneccesary .i can see on the long american high power blue water guns you may need this, but why on a less powerful gun? how much is a 4ft gun flexing with one or two small,(18mm or less)bands? is it possible we are overkilling the situation ? thats an expensive upgrade possibly for little or no practical gain? when they came up w this idea , i thought it was to eliminate barrel flex to reduce shaft whip, etc.. are these problems for average to small guns? enough to warrant expense?

[chrismar]

Densities (kg/dm2)

Water: 1.0
Carbon fibre: 1.7
Aluminium: 2.7
Steel: ~7.9 (depends on the type)

Carbon fibre is stronger for a given thickness than Aluminium. Care to suggest something that beats CF in density/strength measurements?

[settingsteel]

Originally Posted by chrismar

Densities (kg/dm2)

Water: 1.0
Carbon fibre: 1.7
Aluminium: 2.7
Steel: ~7.9 (depends on the type)

Carbon fibre is stronger for a given thickness than Aluminium. Care to suggest something that beats CF in density/strength measurements?

Thats from the technical standpoint...comparing those materials referenced....so then would not wood be the best choice? I won't go into the details of why since that has been pondered...but to answer your question JTKW I think its just another way to keep the economy flowing...new idea, a new want, a new toy....and believe you me- us spearos are gadget galore getters...ask Marwan.

I think your reasoning in part is quite sound JTKW I actually implement in all my guns a CF Belly I added 2 CF stips lamed inside the stock, but stopped, cause you really don't need it (overkill), but alot of guys insist on having it in there anyways (and are happy to pay the "whole lot more $ to have it)...which kinda proves my point.

[alexrom1207]

Carbon fiber is SUPER light not heavy, making the gun more maneuverable and easier to move around. Personally it's out of my price range but in terms of its qualities, I don't think there is much to complain about. Plus it's cool looking

[chrismar]

Originally Posted by settingsteel

Thats from the technical standpoint...comparing those materials referenced....so then would not wood be the best choice? I won't go into the details of why since that has been pondered...but to answer your question JTKW I think its just another way to keep the economy flowing...new idea, a new want, a new toy....and believe you me- us spearos are gadget galore getters...ask Marwan.

I think your reasoning in part is quite sound JTKW I actually implement in all my guns a CF Belly I added 2 CF stips lamed inside the stock, but stopped, cause you really don't need it (overkill), but alot of guys insist on having it in there anyways (and are happy to pay the "whole lot more $ to have it)...which kinda proves my point.

I'm not going to debate the other relative merits of wood guns, but if you take Teak or Iroko as an example, you're looking at a specific gravity of 0.65 kg/dm3. That means it floats, which carbon fibre of course does not.

However, the carbon fibre barrel is hollow, whereas the woodie is not. When you calculate the relative bouyancy of a barrel with the same outer diameter using the different materials discussed, wood loses by a small margin to aluminium, but both lose badly to carbon fibre. The CF barrel also has a lower swing weight by a large margin and with short guns, you don't need mass to absorb recoil.

Attached is a spreadsheet to work all this out. Enter lengths, densities, thicknesses and inner diameters and the spreadsheet will do the rest.

Edit: specific densities for woods, metals and carbon fibre

Attachment also seems to have failed, so here's a mediafire link

[settingsteel]

I can see your angle I agree comparitively speaking as far as the metals (including Titanium for that matter) & CF go, but it would not be a just comparison for wood to fall into this category since it is not hollow to begin with...

[MahiMan]

Carbon guns are great but when it comes to having a noticeable advantage to wood/aluminum..... I didn't really notice when I used my buddies C4. I liked it but felt as if it were more delicate than my wood guns. For example if I were to beat it up around the reef it seems like it wouldn't put up with the abuse. Spare me the formulas and numbers for me it all boils down to the test drive. For what I do mostly CF guns aren't for me, although I will say that thing was dead accurate.

[Pastor]

It is all B####cks most of the time! OK so carbon fire is stronger per given dimension but the trouble is that most manufactures reduce the thickness of the barrel walls to reduce either weight or cost, so any strength advantage is lost. Further, the very thinness of many modern barrels can be a massive danger if is is subject to damage through either long term water ingress or heavy impact. Imagine the consequences of barrel failure on a loaded gun! It has happened.

Realistically, what is the big advantage in the water? The true leveller in the water is buoyancy, like it or lump it. If a gun as a higher mass and a lower volume than water it will sink no matter what it is made of. Gun design is the important thing, not what it is made of.

JT, that's a good question! I swore I'd never buy a carbon gun even though I now own one. My honest answer is that I think many people want them because they are fashionable or they think that hi-tech is the way to go to make them a better spearo. However some of the newer shapes that are being produced in guns would be very hard and expensive to make out of aluminium so if you subscribe to the super maneuverable gun theory then they could make sense but to my mind it makes sense to increase the volume and mass and for that wood is the better choice. Each to their own I guess.

[Marwan]

ok, besides being cool gadgets heres my thoughts on it:
1 - On a size less then 100 you really have to be super sensitive to feel the difference in maneuverability underwater.... all my -100 guns are aluminum
2 - Besides being lighter its also stiffer..what does that mean, no barrel flex..do we ever power a gun to feel that benefit, probably not..except on a long gun once again, for example a 130 rob allen..you could be subject to some barrel flex with the alu models
3 - Anyone that owned an alu gun for many years, knows that at some point water gets in (probably from reef/rock abuse and sometimes its just a stupid o ring that needs to be changed)..and that could be the end of it..with carbin, that doesnt happen..its not a hollow barrel..
4 - Can carbon break..sure..but really how many posts do we have here of someone breaking a carbon gun..
5 - of course design is more important, but for the same superior design, in certain applications, carbon could be more superioer then say aluminum...
6 - every application/hunting condition will play a role in the best material suited...although ive seen blue water carbon guns, i dont imagine that they could ever be superior to wood for that application, the mass and resistance to recoil of the wood should deem it more appropriate for blue water/multi banded guns...

ok i think im out of more points for now
cheers

[alexrom1207]

Carbon fiber is a hell of a lot stronger than you think. But I know what you're saying MahiMan about feeling it's fragile. I have a carbonfiber knife (handle obviously not blade) and I never use it. It's supposed to be really tough, it was expensive as hell, and the makers of the knife abuse the hell out of it in testing, and it stood up just fine. However, it just feels too light so I only use it to open letters with . Carbon fiber will break though, just like an oak tree, because what doesn't bend, snaps. Take a look at some of the sailboat masts that are made out of carbon fiber (and we think it's pricey to use on a speargun!!!!). Those masts are strong as hell and they do not flex, but if you push them just over their breaking point they will snap like nobody's business. Wood and metal will bend rather than break...so if you're overloading it you will be able to tell. Carbon fiber on the other hand. You could stress it to within 1lb of it's breaking point and it would look just fine, until WHAMMM. However that breaking point, if the gun maker hasn't thinned out the walls of the barrel to make it more economic, will probably be far beyond what we can do. Titanium is way too flexible a metal to be used for barrels. I've never see one, so I assume that is why. I know that a knife blade made of titanium is a real pain to sharpen because the edge doesn't stay straight. Not that I'm looking for a reason to not buy a carbon gun...my bank account is certainly reason enough...but if any of these excuses work for you then just throw them into the mix too. Personally I really like the wooden guns. If the varnish chips you can sand them down and re-varnish them and the cost is next to nothing. Carbon can chip/flake, and last time I checked I didn't have a 2000lb press in my garage . Plus I think that wood is just beautiful. If you think that a carbon gun is the coolest looking thing around check out this thread.. http://forums.deeperblue.net/euro-sp...int-heart.html Now that is a pretty looking gun (although at $800 it's not like I'll be picking one up any time soon. Fun thread though... if anyone can explain how carbon fins flex I'd be interested. Perhaps an additive in the resin?? Kind of goes against everything I've heard about carbon fiber.

[settingsteel]

Quite a few excellent comments basically tying into my original posts...just a new way to $$$....but within that context make no mistake carbon IMPO is THE STRONGEST material commercially available with the unique quality it tags along with it...Mahi that schwits strong if you ever take a look at the raw state its a zillion strands of spiderwire thats glued together with poxy another incredibly strong material in and of itself...I should add the carbon belly in my guns serve to stiffen it since the barrels are about 1/2" high by 1 1/2" wide (this guns are slivers) we ran a few prototypes prior and with 2 bands their was about 1/16" flex so the carbon gave it the rigidity we were after...my guns start at 100cm, with most we've built at 110 and above (just finished 2-140's, 1-150) at these lengths powered up with 2-3 5/8's with those tight dimensions the carbon has a perfect justifiable application, and as I had mentioned just the belly alone provides the rigidness it needs....yet a bunch of guys want carbon in the lams...he who dies with the most toys wins

[chrismar]

Originally Posted by Pastor

Realistically, what is the big advantage in the water? The true leveller in the water is buoyancy, like it or lump it. If a gun as a higher mass and a lower volume than water it will sink no matter what it is made of. Gun design is the important thing, not what it is made of.

...but to my mind it makes sense to increase the volume and mass and for that wood is the better choice. Each to their own I guess.

...And there's the point. If you want a 120cm gun that is neutral with a 7mm spear in it, you can forget aluminium (need a 30cm+ ID for 1.8mm walls), use a 36mm OD woodie, or use a standard 25mm ID gun with 1.8mm walls in carbon fibre. Unless you're going to load it up with three or more bands, you won't need the extra weight of the woodie, so with the carbon gun you get a much thinner (read more manuverable) gun with less than half the swing weight.

The advantages of wood, and read this carefully and think about it, only come about in barrel diameters greater than 32mm, where you want to balance out a heavy spear and load it up with multiple bands. From a purely technical perspective, carbon fibre is better than other materials up to that point. Of course with thin guns, the advantage is almost not worth bothering with, so aluminium is fine.

In my opinion, below 90cm (not that I own one), the differences for normal-diameter spearguns is not worth discussing, so aluminium is fine. This does not hold true for guns like the Omer XXV. 100 - 120 suits 1.5 - 2mm wall carbon fibre for guns with 6.5 - 7mm spears loaded with no more than 2 x 16mm bands. 130 - 140 is best with 2mm wall carbon fibre with ID of 25mm for 6.5 - 7mm spears and 28mm ID for 7.5 - 8mm spears. Maximum load of twin 18s. Anything larger than this, or a 120+ gun with more power would require a wooden gun.

[jtkwest]

wow, alot of ideas here. i want to throw a couple out there myself.:i think it seems we all agree on a couple points;short guns dont flex much,(under 100cm) therefore it really doesnt matter what you use in terms of strength , since we never power these guns enough to make a difference. that being said we would only choose our materials for guns this size and under, based on other reasons,:bouyancy and or "swing weight",(what is "swing weight", anyway?) if you want a gun that is easy to swing, you should look into MID HANDLE style design, not euro style, that makes for a MUCH easier swing,"?swing weight?" i dont think there is a such thing as a mid handle carbon fiber gun, since putting slots in it riun integrity of tubular, hollow shapes, hence,"hybrids?" right? the only carbon fiber gun i have ever seen up close is a rabitec 130, and it WAS heavy!!, alot heavier than my homemade 65" , teak laminate gun. but the guy using it, only had two 9/16 bands on it,(hardly enough to flex my teak gun,)so other than the fact that the guy is an oral surgeon, and can buy coolstuff, i dont think he NEEDED carbon fiber, i dont think it gave him any advantage at all over my gun. hence my next question to you all: sure, carbon fiber is super strong, but once again, WHY? if it doesnt give me an advantage then WHY? it doenst look THAT cool. to be honest, i like the looks of some of our homemade wood guns more than the rabitec, i saw, but that is an OPINION not a fact , and certainly not an advantage?? if your gun is long and high powered, it needs a mid handle , so you can back up recoil, with other hand, plus the mid handles swing dramatically easier.. i see alot of ratios and formulas from you tech guys, concerning comparative strengths of raw materials and such, but what is the point of having a barrel that wont flex under 7 or 9 bands, if you only use two or three EVER? and without a fully enclosed trac, the shaft is gonna whip, under that much power anyway? no? so to sum up, if your gun is euro style and doesnt have enclosed trac,and you dont have more than three bands 9/16 or less, you dont get ANY advantage from super strong properties of this material, so you bought it for looks,(or thats the only advantage you RECIEVED, any way,(and looks are opinion) how much band power will it take for an open trac, teak gun to flex enough to matter, that seems to be the equasion we are missing here. and therfor justify carbon fiber?
)

[jtkwest]

by the way, i dont dislike carbon fiber, or any other cool new stuff, i am just trying to nail down facts concerning this issue. i own 5 guns, one aluminum jbl 55 magnum,55"x 3/8 spear,(15 years old, full of water, still works good) one euro riffe110cm, (5 piece teak lam) one riffe comp 45" rear handle,(3 piece horiz. lam) and my two homemade rear handle 3 piece teak lam guns at 60 and 55 inch . so i dont own any mid handle or carbon fiber guns yet. my next home gun is a 65"fully enclosed track,mid handle 5 piece lam, with an ipe piece in the center of lam,(ipe is free to me) so i am not trying to rain on anyones parade.i just am seeking alternate reasons and ideas, and debate is the best way to get there in my opinion.so please tell me if i am wrong and why please!!
)

[chrismar]

You've misunderstood the strength debate with relation to euro guns. If you reread my posts and what Pastor said, it's all about bouyancy. The point is that a euro gun made strong enough from carbon fibre can be neutrally bouyant with a spear in it, whereas an aluminium gun just can't. A woodie requires more mass and a wider cross section to be neutral. That's fine when you need seven rubbers, but most of us don't. Besides, a 140 euro with 2 x 18 has some serious grunt, equal to maybe a four or five 14mm band 55-60" midhandle.