Carbon fiber types? what should i do with my free carbon!?

General Discussion
1

Hi Everyone,

My brother in Law gave me a lot of carbon fiber a few years ago (He made carbon bikes in his shed before Giant, and then Giant stole his design, true story), now i’m thinking of building a fish and wondering if i can put it to any good use?

This is my first post, but i have been reading the forums since I was 15 and I have made 3 boards since then.

-A minimal to learn on (too thick, crap rails, ended up breaking my nose when i went over the front because it sinks)

-A 6’8 short board (width too thin, too thick, not fun)

-A 6’2 shortboard (Perfect apart from its far too thin and i’m not good enough to surf it)

 

So as you can see my experience is shoddy! :slight_smile: But I do still surf my minimal still, and when the 6’2 gets going its lovely)

So i have some carbon, and wondered if the helpful people here could identify what kind it is, and what i might use it for, if anything, on a 6’3ish fish board to help me surf better.

 

The first lot i have is quite normal looking carbon and is fairly thin, but i dont know what oz, maybe 4oz? i have about 7feet of this, its roughly a metre wide

 

The second lot is weird, its directional weave and has this ‘thread’ sticked into it? also, its about double the thickness i think, it feels a little like a rug! i have 8 or so feet of this, its about 2 metres wide.

 

 

BOARD: So with that carbon, what might i use it for on a fish? I want to do something with it, and its free, so the worst case is i mess it up and ruin a blank.

The whole vacuum bagging thing looks pretty hard to be honest, especially on rails. I’m thinking of how i can maybe just put it as a deck and hand laminate it? stomp board type thing? will it be too brittle?

OR how about a deck, AND a whole underside?

 

FINS: also, could i make some carbon fins or is this getting too difficult?

The whole fin setup, board size is another issue, as i’m not greatly experienced. I read for hours on carbon boards here yesterday but couldnt find answers to what kind of carbon i have, or what it is good for, so im a bit confused.

For info, I’m 6feet tall, and weigh 165lbs. i was thinking a modern fish of 6’3 20wide, 2 1/2 thick, with quad fin setup?

 

sorry for all the questions!!!

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p.s i’ll be buying my stuff from seabase as i’m in the UK

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cool you answered two of my questions already  ['where ' ,  and  'what size' ]

 

it doesn't really matter , but how old are you now ? [you mentioned you've been at Sway's since you were fifteen .... 'Sway's has been going since 1999 , though !]

 

fins...

 

  not sure if you were  speaking to me , or about fins haha

 

 .... but ....

 

  yes , you CAN use a layer or two in a fin panel , if you like ? [one layer 'normal'  cloth , then a layer or two of carbon fibre , then the remaing however many layers of 'normal' cloth  , to build up the desired thickness of the fins ....]

 

In fact , THAT is what I recommend doing first !

 

Why ?

 

 .... so you can get some kind of a feel , for how carbon fibre wets out [soaks resin ] . Probably try the cloth featured in the first photo you posted .  Maybe try laying up something like ? a 5x7" ? fin panel first , and make two little side fins .

 

  the reason ?

 

  Well, I don't know about in " mary ol ing land " ,

 

  but here in west oz , the stuff [carbon fibre cloth] can cost up to  $ 80 aus a metre ?! [yes , it's very EXXXXPENSIVE !!] ...so , you DEFINATELY SCORED there , mate ...well done !!  Therefore , DON'T waste any of it !

 If you DO decide to go the test panel / fin panel option with the carbon fibre [c.f.] , stay in touch as ....guess what ?!  I  also got given some c.f. today ...yayyyyy ! 

  Just found something from  a previous thread [my previous usernames have included 'chipfish61' , 'chipfins61' , and  'chippy61 ' .....]

http://www2.swaylocks.com/node/1021299

 

[brought up by typing 'carbon fibre fin panel' into the empty 'search' box ]

 

okay ....I hope this is helpful in some way , mate ?

 

cheers !

 

  ben chipper , west  " orztrayliah " [as your queen lizzy would pro nounce it !]

4

the first carbon set looks like 2x2 twill, i am not sure on oz, but you will have to either wet out the cloth first and than put it where you want or cut lap the cloth,  make sure whnere ever you cut the cloth you tape and than cut the tape. the second looks like unidirectional carbon with either fiberglass or maybe a white kevlar? but usually kevlar is yellow in strands like that. but i am sure thier are others who can answer your questions a bit better than me. 

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Hi Guys

Thanks Fins, that is useful! Making a carbon fin set would be good mess about. Do you think i should make fcs style fins? Or start a set to glass on the board? I wondered maybe if i had some old fins, if i could cut the fcs ‘base’ off them and then make a new carbon fin to go ontop, otherwise im not sure how i’d do the fcs bit to go into the board…

Fins: I’m 27!!! so i think when i came on here hwen i was 15, it had only just started. maybe i registered and posted? I’ll have to check that!

 

a2tall: What is cut lap? I guess i can search for that on the forum and find out. Wetting cloth first sounds easier, if i was only using it for the deck then it would be easier as its just laying it flat. I’d paint a black area first so the edging looks alright.

 

What are your opinions on top deck AND bottom of board being carbon? If i just do the top deck, will it make an area likely to crease where carbon ends? this is why i thought i should do bottom too. Also, is carbon on its own alright, as if i did the bottom of the board, surely its usually only one layer of material right? I thought I’d stay away from carbon rails, because they reduce flex and also its gonna be hard to do rails with carbon, i find it hard enough in glass!

Sorry for the basic questions,…

 

 

6

A carbon fish would be sweet looking. Careful of the heat, being black it can delam rather fast. Not to repeat but the first is a 2x2 twill. Alter the weave direction in multiple layers for maximum strength. The second batch is a uni directional cloth. He used this for the core of the bikes and then the twill for cosmetics. Unidirectional is super strong, with the right amount of layers, again alter the direction of the fabric. The first layer will run at 90 degrees the second 45 and so on depending on the required engineered strength. The white cloth normally is Kevlar and this serves to hold the fabric together and im not sure about this cloth but it can also be called tracers. Tracers are used when laying up multiple layers so you can see the direction each on is going. Tracers usually go with the grain of the fabric or against, this looks like its at 45. The main thin with carbon is to alter the weave with multiple layers. 0/90 ±45 is common. Vacuum bagging is gonna send your cost through the roof. A pump will run from 400 to 2grand for a good one. There are vacuum generators that use venture and connect to a larger air compressor. Cost around 50 bucks. These work good but you need a high volume air compressor. You can use plastic sheathing for your bags and duct tape to seal.

Carbon is difficult to work with. When you cut it, lay out masking tape on the cloth and cut the making tape. That way the roll and you workable chunk will not fray apart. Practice weting it out with resin and just make a few flat items. Key chain, chevy bow tie, anything to get practice. Maybe start with fiberglass for the added practice

Carbon deck would look nice, wont be brittle, just keep it out of the heat and direct sunlight. Fins would be a good idea, Lots of layers though. Wet out and cure a 2 inch piece of cloth and measure the thickness with a micrometer, divide that by the desired thickness of fin. Draw each layer out on clear plastic, get the shape you desire, lay cloth on plastic, wet it out, smash them together, put a layer of twill on top and back, cure them, light land, hot coat, gloss coat and done. I can elaborate more. Im making some myself. You could also put a layer over your existing fins to give them a carbon look.
Good luck,

7

If you cut a square piece - say 6"X6" and weigh it, you can determine the weight per yard of the material.  Anything much over 9 oz/sq yd might be overkill for surfboard depending on your core foam? 

If you have access to a large pane of window glass, like a sliding glass door, or an air-tight table top covered in plastic, you can lay up a section on the glass (under vacuum even), peel it off after a green cure, and trim with scissors before vacuum bagging to the board as an inlay.

Check out Greg Loehr's 'Timberflex' videos from Cerritos College and substitute your carbon panel for his bamboo veneer. 

I've done a carbon/bamboo veneer composite deck inlay that was super strong following that basic technique... on the board below, I vacuumed the 'prefabbed' deck inlay against a vacuum table before cutting and attaching to the board. The bottom and rails were hand laminated before hand laminating clear glass over the deck and rails.  Not super light and overkill really for general use. 

It still didn't survive a trip against some rocky bluffs after I lost it one day.

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Yo Beanis! 

 

That first cloth ya got there is actually very unusual. Its a 3x3 twill weave, In 14 years in aviation and marine composites I’ve never seen it used, as 2x2 twill is the standard. Difficult to say what weight it is, but it looks like a 3k tow, so my guess is about 5 to 6oz. The second is a Bi-axial ±45. The “stitch” is typically polyester so it isnt difficult to cut through (unlike kevlar). This cloth is typically used in thick laminates where you can laydown a lot of fibre in one go running in the right directions and because its not woven you dont get “print though” on moulded parts.

I suspect its gonna be a bit heavy for a lam, but as you hit on, fins would be sweet. It can take a while getting used to how it wets out by hand, but with vacuum infusion we’ve had awesome results. 

I bet you already know this, so please excuse me if I’m teachin gran to suck, but only use epoxy, wear a mask and keep dust to an absolute minimum. 

Good luck there and hope to see some cool photos posted soon!

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wow, martymo, looks like i’ve got something unusual here then?!

I did read about only using epoxy, and your not teaching a gran to suck eggs, i’m quite a novice with all of this!

 

This vacuum bagging sounds difficult to achieve at home, with a very low budget. I do however have a 5 foot by 2 foot glass desk, if this helps? can i lay out on that?

Im a bit confused, is it not possible to paint epoxy on the deck, then lay on the carbon, then wet that? I really dont know how carbon works…

 

So i’m thinking what would be the best use of carbon in weight/strength and ease of build ratios.

what about just carbon on bottom and 3/4 deck. If i were to do this i could avoid carbon rails, which seems difficult, no? I could add the patch to the bottom, cover it with glass, then do the same for the top. would this work? i’d be left with a thick bottom, but if i used 4ox glass would this work ok and not be too heavy/stiff for a fish?

 

I need some suggestions i think!

 

Thanks for all the info so far, I’ll definatly add photo’s along the build. Though i think i won;t start for a few weeks, im poor and i have to hand in an MA dissertation in two weeks! (This is good distraction!)

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junkyarddog: Yes please can you elaborate on the fins, as i think i’ll make these first.

Do you mean i make them from fiberglass inner and the carbon just forms the final layer? Also, do you think its gonna be easier for me to make glass on fins, or fcs style fins?

 

Cheers!

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not in the UK it won’t! Its rained solid here all summer

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"I do however have a 5 foot by 2 foot glass desk, if this helps? can i lay out on that?"

"Im a bit confused, is it not possible to paint epoxy on the deck, then lay on the carbon, then wet that? I really dont know how carbon works..."

A glass desk would be perfect for the prefab inlay method.  Just be sure to wax the surface so it is easy to peel the carbon off once it sets up.  Hand sand the surface a bit before laminating with it. 

It is certainly possible to wet out and laminate carbon as you would with ordinary fiberglass.  It gets tricky with a cut edge and freelaps are a friggin' mess.  The advantage of the prefab inlay is you can use a template and cut with a pair of scissors exactly where you want the edge to be.  It ends up with a very clean edge. 

Trimming laps or inlay edges with a razor blade is harder.  I've used multiple layers of tape to build up a 'step' that is visible through the carbon.  I've also resorted to a cutoff wheel on a Dremel tool to cut rather than a razor blade after it set up too hard.

In any case, you have some good material there.  I hope you figure out a way to use it!

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maybe martymo can help me out or corret me if need be. ive got 2 years aviation composites and have learned from him just in this post. here goes.

when we do repairs we grind/sand/buff out the damage. for every layer of carbon we normally sand out a half inch from the repair area so if the part has eight layers than a circle patch would be at least 4 inches in total. the part before laying up the cloth will have a taper all the way around the damaged area that leads to the damage itself. we have to put the strength and plys back in due to what we took out and also for the damage. at this point you can look at the part and are able to see each different layer of carbon fiber all eight of them. now i take clear baggin film, any clear plastic will work, and trace each layer individually (with a silver marker) that you can see. when that is done, lay your dry cloth on the plastic that you used to trace to repair plys and wet it out carefully with resin, now put another piece of plastic over that, use some type of plastic spreader to squeeze the extra resin out. youll have plastic/carbon/plastic. get sharp scissors and cut out the shapes that youve created based on the damaged part. paint just a little resin on the part, take the smallest repair ply, peal off 1 side of the plastic lay it on the part matching it to where it goes as best you can, pat it down and peal off the top layer of plastic. the carbon will stay down and provided you take the plastic off slow and carefully it will not fray on you.

we tend to think more resin is better, but it is in fact the opposite. shoot for 60/40 or 70/30 where the cloth would be 60% of the total weight and resin 40.

Making the fins will be just like repairing a multie layerd part but without any damge. you have to figure out the thickness of a single layer of your cloth after its cured and the thickness of the finished fin.

im using 12k carbon that i got for free, this is a test for and at this point can see any errors in my theory. my final fin will be 3/8 in thick or .375 and a single cured layer would be .019. .375/.019 = 19.7 that means ill have 19 or 20 total layers of carbon. this is for a solid carbon fin. foam core might be lighter. and also one side will be flat and i plan to vacum it to a glass table. but you could make two separate halves and bond them together with resin. its powerfull stuff. anyhow. with 19 layers i have to figure out the foil of the fin and draw each layer on the plastic, remember each ply will be different shape to create the foil. then from here its just like the repair described above. i would suggest doing one final layer after the fin is shaped and looks the way you want it to. i call this the money shoot. you can do a couple layers at a time just to check your progress. but if you do want to add to to cured carbon just sand/scuff it so you create a good mechanical bond. good luck, take pictures

i hope this helps. been a looong weekend.

15

Well bean i am the contrarian of the day here.

The light stuff picture first isn’t enough to lay up a board.

The heavy stuff is way too strong and stiff and heavy for a board.

Whatever you do, don’t make a solid carbon fin -too expensive/waste of material, heavy, and little flex.

Plus sanding that much carbon is not cool for you lungs eyes skin etc.

Use a tiny bit of carbon in a fin on the skin or on the midline, ok.

Carbon keeps forever, so  I will say save it until you know what to do with it, contrary to what others have said.

Unless you have some more sophisticated way to use just a bit of it (hint -rails or stringers or springers).

I got into carbon on my first composite project, and it was totally unnecessary. But cool.

 

 

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hi bean !

 

  You could try to make a thin panel for glass on fins , like in the link I posted . maybe just a couple of little side fins , maybe just two layers of normal cloth , then two layers of carbon fibre , then , say , 20 layers of normal cloth on top of that [laid up 4 layers at a time , with a roller.

 

 By the way , I have used polyester resin for ALL my fin panels , carbon fibre inlay ones included ... I haven't used epoxy .

 

  cheers !

 

  ben  

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bwd, thats good advice.

I think i’ll just make a top carbon deck for this board and leave it at that, maybe some fins too but only outer layer.

I might end up laying direct on board because even if i lay on my glass desk, i’ll still have to vacuumbag it to the deck (Right?)

 

When i actually get the stuff and get going i’ll use this thread as the build thread!

Thanks so much for everyones input!!! its very very helpful!

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I reckon if you use a combo of Junkyard's and Fin's methods you'll end up with some sweet fins!
 
Regards polyester and carbon, it usually ends with a poor laminate, unless you've got hold of some special silane treatment carbon specifically for boat building. I'd urge you to use epoxy as the matrix bond is far far superiour. Imagine running a F1 car on tyres off a 2CV....well that's like carbon and polyester. You've got some nice cloth there, it would be a shame to not make the most of it. BTW the weight of a solid glass versus a solid carbon fin will be very small. The stiffness will be hugely different. I did a sailboard fin with a mix of balsa, glass and carbon, but that build wouldn't work for a FCS placement. 
Good luck!
 
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I’m just messing with the carbon now on my glass desk, i can totally see why people vacuum bag - the resin just mounts up doesnt it, and its hard to smooth down.

 

I’m, wondering, because vacuum bagging gonna be a bit too expensive for me i think, if i can just improvise. If i put a thin layer of resin down, and layed my carbon over it, cut it to fit the deck, and left this to dry tacky. then put the glass cloth over the top and glass as usual, the carbon would be stuck and not move and fray? or even leave the carbon to dry solid before glassing over top?

I know i’m being cheap and its a bodge, but if this would work then i’m happy. I’m not to fussed about what it looks like, perfect lines etc.

Infact i though i could lay a frayed piece of carbon with ‘carbon mess’ written over the top as my ‘logo’ :smiley:

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never had ANY problems at all with cf and polyester , i have made thirty cf fins .

 

  being  that it is only two layers in a panel , surrounded by [in the case of my fcs fins i make ] , up to 34 layeers of normal 4 or 6oz cloth , there is no reason for problems .

 

  but others experience may vary i suppose ?? [not sure WHY , though ...]

 

  cheers

 

  ben