Now that you know what Carbon fiber is, (if not, you can learn the basics about Carbon fiberhere), hope you are excited to make something out of Carbon fiber (just imagine how light and good your part is going to look). In this article, you will learn how to make basic Carbon fiber shapes and parts using three different techniques: hand-layup, resin infusion and pre-preg Carbon fiber. Vol.1 will focus on how to make flat sheet. But similar strategy can be applied on more complicated parts by using molds.
The first technique is the simplest and the most economical one among the three. The reason that it is called hand-layup is because the resin is laid up on the Carbon fiber weave by hand typically with a brush, squeegee or a roller, but hand nonetheless.
What you need for hand-layup:
1. A good surface to make your flat sheet. Glass is the best surface for you to work on. But other materials that are more accessible to you such as aluminum sheets can also work for this purpose.
2. Release agent. The reason you want release agent on your working surface is that you want to get your Carbon fiber part out of your working surface and not attached or stick to it. Typically, a mold release wax and a chemical release agent such as easy lease from Easy composite can be used as your release agent. From past experience, a chemical release agent will result in a better final surface finish since mold release wax will tend to leave tiny marks and spots on the final surface.
3. Paint brushes, squeegees or rollers to lay up your resin.
4. Carbon fiber weave of your choosing. Be aware that different type of Carbon fiber weave will give you different properties in your final part.
5. Epoxy resin or laminating resin of your choosing. Again, you can choose different resin to give you your desired properties. Resin usually comes in two parts. Part A and part B. Be mindful of their properties, such as curing time, viscosity and so on, when working with your resin. Epoxy resin will get hot once you mix it up and starts to cure.
6. Mixing sticks and cups.
7. Gloves to protect yourselves from Carbon fiber and resin.
8. A good scale to weigh your resin on. Tip: you can wrap your scale in food wraps or plastic bag to protect it from resin and keep it clean.
What to do:
1. Prepare your surface for release agent. Clean up your surface with acetone and make sure your surface is dust free, since everything that is on this working surface will more than likely to end up in your finished laminated surface.
2. Apply release agent on your surface. If you are using wax, you need to apply several layers of wax and buff it off between each layer. If you are using release agent, you can either spray it on or wipe it on with a piece of cloth or tissue paper.
3.While you are waiting for the release agent to dry, you can start preparing your layup. First, determine how much Carbon fiber you need for this layup. Normally, it is dictated by the thickness of your part. If you know the weight of your Carbon fiber, for example, say your Carbon fiber is 650g/m2. One layer of this will usually translate to 0.65 mm thickness once it is cured. Some will call this thickness the consolidated thickness of the Carbon fiber. Cut out your carbon fiber you need for this layup to the desired shape and weight it. Remember this number and it number will be the amount of resin you need. Typically, the ratio between Carbon fiber weave and resin is 50 to 50 by weight. For example, if your Carbon fiber cloth weighs 50 grams, then you will need 50 grams of resin and hardener to completely wet out the Carbon fiber. For clarification, 50 grams is the total weight of your resin and hardener. Now, to be safe, you may want to make more resin than say 50 grams, just in case you need more. After you have calculated the resin amount, carefully read the instruction for your resin, and mix your resin with your hardener according to the recommended ratio. Note that, you can control how fast your resin cures by choosing different types of hardener. Some hardener will make the resin cure faster than the others.
4. After your release agent has dried, wet out the surface using resin and apply your first layer of Carbon fiber. Use a squeegee or a roller to completely wet out the Carbon fiber and eliminated as many air bubbles as you can. The less bubbles you have in your laminate, the better you final part will be. It may sounds labor-intensive and time-consuming, but it will worthwhile in the end.
5. After the first layer of Carbon fiber cloth is done, apply resin on top of the cloth and basically repeat step 4 until you have applied all the Carbon fiber.
6. Apply a final layer of resin on top the Carbon fiber and work out any air bubbles that are trapped in the laminate.
7.(Optional) apply a layer of peel ply on top of your laminate. This will absorb the excessive resin in your layup and help leaving a smooth finish on the final part.
8. Wait for the layup to cure according to the hardener that you used.
9. De-mold your part, trim your part and enjoy.
For more details on hand layup, play the following videos.