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What is the best/easiest way to make carbon fiber tubing?

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I need to make some 1" id carbon tubing for a project that I am working on. Would it be best to make a mold with two halfs and then bond the two halves together. Or should I use a piece of aluminum tubing as a plug and wrap it around that? I feel that using a piece of tubing as a plug would probably be easer but i'm not sure how well that will work when I vacuum bag it. This does not have to be very precise so wall thickness and strength are not that important. Any input or suggestions?

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Buying it is nice if they make what you want but if you want to make up a custom velocity stack in trick colors, try these guys for CF/Kevlar/Fiberglass sleeve material in a number of different colors and a couple of thicknesses.

http://www.solarcomposites.com/composites/carbon%20fiber%20sleeves.html

You make the mold and slide the material over the tubing or whatever you are using and apply your epoxy or poly and get some really trick stuff!

Swiss

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Fly fishing poles are made of carbon fiber on steel mandrels, but they have a taper which allows removel.

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I already have the material so i'm not going to be buying anything. I think i will try using aluminum as a plug. Because aluminum has a much higher thermal expansion coefficient than carbon fiber I should be able to freeze it once everything has cured and that should help to separate the carbon from the plug.

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Can you not take a pipe that has a 1"od, then drill a a bunch of holes in it, seal both ends and add a fitting so you can pressurize the inside of the tube, air will blow out of the holes you drilled. This way you can lube up the outside of the tube with mold release, then wrap the tube with the carbon fiber, epoxy it, vaccume bag it etc. Then when you want to remove the CF from the tube, pressurize the inside of the tube and the CF should slide right off like butter!. Just like using compressed air to get your handlebar grips off.

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Can you not take a pipe that has a 1"od, then drill a a bunch of holes in it, seal both ends and add a fitting so you can pressurize the inside of the tube, air will blow out of the holes you drilled. This way you can lube up the outside of the tube with mold release, then wrap the tube with the carbon fiber, epoxy it, vaccume bag it etc. Then when you want to remove the CF from the tube, pressurize the inside of the tube and the CF should slide right off like butter!. Just like using compressed air to get your handlebar grips off.

I already went ahead and tried laying it up with some fiberglass just to test it out, I will have to wait untill tomorrow morning to see how it turned out. If my method does not work I may give your idea a try.

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Here are a couple pics of a tube i made out of fiber glass. It turned out very well. I already went ahead and layed up a carbon one, i'll have to wait and see how that turns out.

IMG_0026.jpg

IMG_0029.jpg

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Here is the carbon tube with some aluminum pieces that I also machined. I'm trying to make some fork subtanks, and i'm surprised at how well there coming together.

2010-03-08153743.jpg

2010-03-08153755.jpg

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Here is the carbon tube with some aluminum pieces that I also machined. I'm trying to make some fork subtanks, and i'm surprised at how well there coming together.

2010-03-08153743.jpg

2010-03-08153755.jpg

Looks cool, just make sure the pressures arent high and be warned that pressure vessels can be dangerous. My friends have done some carbon control arms for a small car, you should make the end pieces a press fit and hone them to fit inside the carbon VERY tightly.

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Another idea, if you're still experimenting, is to wrap the carbon around a styrofoam cylinder.

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I've been down this road once or twice so far. Here is what I would do:

Use a fluorescent light bulb as your mandrel. Use a high slip release - basically any semi-permanent mold release (I like Enviroshield from www.zyvax.com). If you use wax it doesn't work well. Use carbon fiber braided sleeve (www.cstsales.com) because it acts like a chinese finger trap it compacts nicely. The tighter you pull the ends, the tighter the entire layup gets on the mandrel. Once cured break the bulb and get the glass pieces out.

As far as the aluminum fit to carbon - be careful! DO NOT MAKE A TIGHT FIT! use thickened epoxy to take any gap between the carbon and aluminum. If you have carbon touching aluminum you can get galvanic corrosion causing a spectacular failure if you get any pressure. :lol:

It is generally a good idea to use a light layer of fiberglass between the aluminum and carbon just to make sure there isn't any contact. :banana:

You can get some great ideas from www.epoxyworks.com as well.

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I've been down this road once or twice so far. Here is what I would do:

Use a fluorescent light bulb as your mandrel. Use a high slip release - basically any semi-permanent mold release (I like Enviroshield from www.zyvax.com). If you use wax it doesn't work well. Use carbon fiber braided sleeve (www.cstsales.com) because it acts like a chinese finger trap it compacts nicely. The tighter you pull the ends, the tighter the entire layup gets on the mandrel. Once cured break the bulb and get the glass pieces out.

As far as the aluminum fit to carbon - be careful! DO NOT MAKE A TIGHT FIT! use thickened epoxy to take any gap between the carbon and aluminum. If you have carbon touching aluminum you can get galvanic corrosion causing a spectacular failure if you get any pressure. :lol:

It is generally a good idea to use a light layer of fiberglass between the aluminum and carbon just to make sure there isn't any contact. :thumbsup:

You can get some great ideas from www.epoxyworks.com as well.

+1!

You can use vasoline and a non-lubricated condom as an easy mold release. Smear the vasoline on the mold, and pull the condom over it, but don't get the vasoline on the outside or it'll contaminate the laminate. Then lay up the fiberglass and at least 3 layers of carbon if using 3k. Cf braid is really nice to work with and should be stronger than fiber cloth because the fiber strands are longer as there's no seam. If I was making those tanks, I'd use 3 layers of 12k, or 10 layers of 3k 1" braid. If you can find heat shrink large enough, it works great to compress the laminate instead of vacuum bagging; break out the heat gun though, you don't want to use a lighter or torch to shrink the heat shrink!

BTW, have you considered laminating the aluminum pieces into the tube? I laminate aluminum blocks into prosthetic legs that hold the knee onto the socket, and those blocks see way more force than your tubes will. Just machine in some grooves for the laminate to hold onto. I guess if you did that, a styrene based foam would work best as a mold because it could be dissolved with acetone.

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Awesome work, they look really trick!

How much do they weigh?

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