Evan , good job on the write up . I need to learn how to make pdf documents… is there a website for that?.?.? hehe
Bill
Bill, you just need Acrobat writer and use that to import your word document and convert it to pdf format. PM me if you need help.
Ok guys part II is up - http://www.carbon-werks.com/forum/viewtopic.php?t=23
Part III will cover mold making and whatever else that I might have forgotten from part I and II.
Bill is working on something too so I will keep you guys updated.
Question: Ok, it’s done. But I can still feel the texture of the fabric. What do I do now?
Answer: If you want a flat and smooth surface to give you that 3D effect, you have to build up several more layers of epoxy resin. How many? It’s hard to say because different epoxy has different viscosity characteristic.
Will subsequent layers of epoxy resin stick to the previous layer?
Do subsequent layers have to be applied while the old layer is still tacky or completely dry (or does it matter)?
Ideally you should apply the next layer as the existing layer is just tacky enough so that it won’t sag when you brush on a new layer. It’s ok too if your existing layer is already cured. Some light sanding is ideal in this case although not neccessary. If your epoxy has a wax oily like substance in it then you should definately get rid of that before applying the next layer.
I’m a little confused about what to do around the edges of a piece.
Scenario: trying to cover an existing E36 interior part with CF, e.g. the little piece above the glovebox.
So you cut enough fiber material to cover the piece plus about a half inch all the way around. You put the epoxy on everything and place the fiber on the part.
But you don’t wrap any fiber around the edges of the part, correct? So when it dries you’ve got half an inch of hard FRP that you have to cut off.
Or maybe not.
Do you cut the excess off before it hardens all the way? Or do you wait until it hardens and use something to cut it and then sand the edges smooth? What do you use to cut it?
As I said, I’m a little confused about the finish on the part.
Can you elaborate?
You can just use the sharp razor to trim off along the edge. You can do so as soon as it cures hard enough where the fabric won’t budge or you can wait until it completely cures. With just one coat of epoxy, you should be able to trim it using a razor without a problem.
I don’t understand how the Carbon Fiber layer doesn’t stick to the plug. If you cover the plug with epoxy, and then lay on a epoxy-covered layer of carbon fiber, and let it cure… how does it come apart?! Are there certain materials that the epoxy won’t stick to, or what?
They sell a certain kind of plug wax I think.
I would think that would be an important step in this little how-to :?
I wonder about that. Do you peel the tape off? Do you cut it off since it SHOULD be on the excess, not the finished product?
What about having nice straight edges for a very complicated part, where one single piece will NOT cover the entire mold (like placing the sides of a fender as a cut out piece, and the top another, then of course, layer some more to join the seams)
Resin does not bond to any type of plastic. If your plug is made of wood or metal then you’re fine. Other than that you risk the chance of delamination down the road. Some sooner than later.
I don’t peel the tape off. It’s part of the excess that gets trimmed off. That’s why you should always have at least an inch or two of excess material yet not too much. The only way you can get perfectly clean line is via prepreg… other than that you’re still going to get some fray no matter what. There are some tricks that you can try though.
a. spray some adhesive (3M Super 77 for example) along the line that you’re going to cut. It’ll hold everything together so that you can cut a nice and neat line. The problem is the area becomes tacky and it’s hard to handle.
b. take a bottle of clear nail polish and draw a line along where you want to cut. Don’t use too much nail polish because the resin won’t be able to penetrate those areas and wet out your carbon cloth completely. So let the nail polish cure and cut along the line.
I don’t quite understand what this means, I’m sorry…
so, if my plug is plastic, metal, or wood, I can just lay the resin-soaked carbon fiber on the resin-coated plug, and then when it cures, just remove the carbon fiber from the plug?? If its another material, then I have to use some sort of ‘plug wax’ so I can seperate the two? what about fiberglass? I’f I have a fiberglass mold and am laying the carbon-fiber upon it, will I be able to remove the carbon when it cures, or do I need the wax? Thanks for your help.
Odd, coulda swore I posted this yesterday.
Anyway.
Does the blue tape come off at any point? After wetout?
Or do I keep the taped edges OUTSIDE the mold peice; if so, then what if I have a large compliated mold, where I need to lay the CF in sections in the mold, but want a nice clean edge to each piece?
If you’re trying to remove the carbon part from a plastic plug/mold then you don’t need to use anything. Although you should still apply wax so that it will come off easier. For everything else you’ll need some kind of mold release applied to the mold/plug first before you apply the resin/carbon. PVA is a common mold release, wax is also very widely used. There are other chemicals as well but they’re more suited more mass production purposes. They’re called semi permanent mold release which you apply once for multiple releases.
One more thing to add. Ultimately it comes down to how porous the surface is. If you have a smooth plug/mold, it’ll come off much easier than if you have a rough or porous plug/mold.
Sweet, thanks!!!
how do i gett the PDF f\ile?
I lost the PDF file. I’ll make another one.