making carbon fiber parts

I can't much info on fabricating carbon fiber parts, such as pad eyes, brackets, etc.   Most of what I find is just a brief description.  I don't know how to make a good mold out of basic workshop materials, and I can't vacuum bag.  Any info would be appreciated.

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RE: making carbon fiber parts


Give me a call at the shop, or shoot me an email. I might be able to help you out. It is not as hard as you might think.

RE: making carbon fiber parts

Without a vacuum, using positive preasure form clamps and cauls, you'll get the best results for items that have curvature in one dimension only, and generally not things such as the winch pad in the CLC pic above.

I recently made some padeyes, and here's how I went about it:

Glue a thin stip of wood down the middle of a larger piece of something flat. The stip's dimenions match the opening size of the padeye. Cover the top of the strip and flat wood with clear packing tape for release. Cut two strips of wood that approximately match the remainder of the flat area on the main mold piece, gently radius one long edge. Cut a piece of peel ply a little larger than the main mold piece, and several pieces of carbon, and a sheet of mylar drafting film, all the same size more or less. Wet out the carbon on a plastic sheet covered wet-out table and using a squeegie, stack them on the peel ply, cover with the mylar, set on the main mold, and set the two half-cauls on each side of the thin strip and clamp them together sideways and downward. When done, things should look about like this:

This is for a half dozen padeyes, after removing the peel ply and mylar. Next, cut to width, and cut into strips (a diamond wetsaw is swell, but a metal cutoff blade in a grinder works, as does a jigsaw although the blade dulls quickly), sand edges to suit, and prep the gluing surface and apply. The peel ply texture on the underside needs no further prep for gluing, but the canoe should be masked, coarsely sanded, and then a toughened glue such as GFlex is ideal for max strength and ordinary epoxy is fine for the other 95% of uses.

As you begin to play with the carbon, you'll see molds in all the little household and shop objects that surround you- the inisde of a tupperware dish or margarine container is a good start for the shape in Joey's pic above for instance, and so on.

RE: making carbon fiber parts

Joey, I am going to send you an email, thanks.  Nemochad, if you can use mylar for the top, visible surface, could you use it on the bottom side, instead of peel ply?  This is how I thought you would make pad eyes, but I was wondering how to get a good finish on the visible surface without recoating or fill-coating.  I would like to find how to fabricate a concave surface, that would be curved on all sides.  I could build a male mould, but I don't know what to coat it with to achieve a nicely finished surface.  I would like to be able to use mostly typical found shop materials.  Thanks. 

RE: making carbon fiber parts

Yeah, or omit the peel ply and rely on the packing tape. You'll need to rough up the bonding surface, but that's not a big deal.

You'll always get a better surface against a clean mold. If using a male mold and no caul or bag, then you get open weave and the need to add fill coats. It can still look the part, just won't be as light as possible with better methods. 

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