Want to learn how to make your own shiny, sleek, carbon fiber phone case? Just follow these simple steps to create one for yourself and show off to all of your friends!

Step 1: Selecting Your Materials

Fibre Glast 3k 2x2 weave, image credit: http://www.fibreglast.com/product/3K_2_x_2_Twill_...

Plastic Wrap:

2 kinds of plastic wrap are needed. A standard cling wrap is used to protect the work area from plaster and epoxy. Glad Press and Seal is used to line the interior of your chosen phone case, so that a mold can be made without ruining a perfectly usable phone case.

Plaster:

The plaster is used to take a mold of your phone case. This tutorial uses DAP Plaster of Paris.

Carbon Fiber:

Because a phone case needs to take a beating from any direction, select a carbon fiber that is woven, rather than unidirectional. This tutorial uses Fibre Glast 3k 2x2 weave.

Hard Epoxy:

The hard epoxy is used to shape the carbon fiber and give the phone case some rigidity that it is otherwise lacking. This tutorial uses Fibre Glast 2000 Epoxy Resin, with Fibre Glast 2120 2 Hour Epoxy Cure. This epoxy is 1 to 1.

Shiny Epoxy:

The shiny epoxy is used to add a gloss coat to the phone case to make it look nice! This tutorial uses TAP General Purpose One to One Epoxy Resin and Hardener. As the name indicates, this epoxy is also 1 to 1.

Tools:

Tape (to secure plastic wrap to work area, and make cutting the carbon fiber easier)
Shears (for cutting carbon fiber)
Popsicle sticks (for mixing plaster and epoxy)
Disposable cups (for mixing plaster and epoxy)
Gloves
2 Disposable paint brushes
Vacuum bag with vacuum (to ensure that the case follows the contours of the mold)
Chisel or flat head screwdriver
Hammer (to break the mold out of the case, once it's set)
Dremel with cutting head, and sanding head (to cut port holes and do finishing touches)

You will want to wear gloves throughout this process to protect your skin from epoxy and carbon fiber fibers. Like fiberglass, the fibers can irritate your skin if exposed, as they are very small and sharp on their own. Once hardened, epoxy is very hard to remove from your skin, needing ethanol or a similar solvent to remove it. The easier method is to just be careful not to get any on your hands by using gloves! We used vinyl gloves, though any type of gloves should work just fine!

Step 2: Creating Your Plaster Mold

Lay down normal plastic wrap onto your work station and secure with tape. This will become your work-space for the remainder of this project.
Rub the Press and Seal into your existing phone case, trying to avoid wrinkles where possible. The best way to do this is to press the Press and Seal onto the middle section of your phone case first and then work outward toward the edges. If your case has any large gaps like mine, you might want to use tape to create a barrier to keep the plaster from bulging out. (Notice how my plaster mold has straight edges even when the case has a void.) For smaller sections the Press and Seal will create a barrier on its own.
Finally make sure to indent the press and seal around any openings in your phone case, for things such as logos or camera openings. To do this simply press additional Press and Seal into the openings and leave it for when your pour your plaster. You can see how the openings are clearly marked on my mold.
Mix the plaster according the instructions on the container, and pour into the Press and Seal protected phone case.
Allow the plaster to set according to the directions on the container, and then carefully remove the plaster mold from the phone case, discarding the Press and Seal.
Using a Popsicle stick, file the plaster mold to remove as many imperfections as you can. Wetting the Popsicle stick slightly can make this easier for large sections.
Once the mold is the way you want it, pat it down with a slightly damp paper towel to remove any excess plaster dust. Your carbon fiber case will look exactly like your mold, so any ridges, bumps or dimples left on your mold will show in your final product. Be sure to smooth all sections of your plaster mold before moving on.

Step 3: Preparing Your Epoxy

Carefully mix the resin and hardener of the hard epoxy together, according to the manufacturer's instructions. Avoid causing bubbles while mixing, if possible. Mix resin and hardener together slowly in a larger cup, though only a small cup's worth is needed. Do not whip the epoxy as this will introduce bubbles. Keep in mind the drying time of the epoxy used. We used a 2 hour epoxy to allow ourselves plenty of time to create our lay up, but if you use a 30 minute epoxy you will want to move quickly from this point on.

Step 4: Making Your Carbon Fiber Layup

Warning: Make sure to be wearing gloves for this next section! When cutting carbon fiber small shards will come off of the sheet. These shards can cause irritation or rash if your skin is exposed to them, and can be harmful is breathed in. You do not need extra ventilation, but do keep your head away from the cutting area.
Using your shears, cut a rectangular section of carbon fiber to lay over your phone. The exact dimensions of this will depend upon which case you use, though it should be somewhere in the range of a 6"x8" rectangle. To measure how much you need lay your mold onto the carbon fiber sheet measure our 1" above and below the top and bottom of your plaster mold, and measure out somewhere between 1 1/2 and 2 times the width of your phone case. It is fine if you cut more than this, but you will have to trim excess later.
Once you have your carbon fiber sheet, move both the sheet and your plaster mold back to your work space.
Gently apply epoxy to the back and side surfaces of your plaster mold, this is used to secure the carbon fiber to it.
Wrap the carbon fiber sheet around the front side (the better looking side) of your plaster mold. Like when you were using the Press and Seal, press the carbon fiber into the center of your mold and work outward leaving no air bubbles. Only use your gloved fingers as the carbon fiber can be stretched easily (this will deform the final weave of your phone case).
During this process use your epoxy brush to add epoxy to the top surface of your carbon fiber to secure it in place. Continue to press your carbon fiber onto your mold and secure with epoxy.
Carefully wrap the carbon fiber around the sides of your mold. At this point the weave might be stretched out because you are working with a rounded surface. There is no way to completely avoid this but with care it can be minimized. You may need to cut your sheet to properly wrap around the corners.
Wrap any excess carbon fiber around the back of your mold and seal the whole thing with additional epoxy. You may need to tape the excess to the back of the mold to keep it in place.
Finally take your finished layup and place it inside a vacuum bag. Seal the bag and start the vacuum and work any air bubbles inside toward the vacuum nozzle. This will create a tight seal between the carbon fiber and the mold to create your phone case. Leave for at least 2-3 hours to create a full vacuum and allow the epoxy to set.
If you do not have a vacuum bag I have seen videos where this is done with layers of duct tape. As long as you are able to create a tight seal between the carbon fiber and your plaster mold there should be no issue using this method, though it might not give as nice of a product as using a vacuum bag.

Step 5: Breaking Out Your Mold

Once your epoxy has set, remove your mold and phone case from the vacuum bag (or unwrap it from your tape).
Remove the excess carbon fiber from the back of your mold using a Dremel tool. We used the type that has a rotating circular head to cut off our carbon fiber. If this kind is used do not use it near your fingers. Hold the side opposite of the one your are cutting. Alternate tools such as an X-acto knife can be used.
Try to cut as straight of lines as possible. This will form the basis for the back of your phone case, creating the part that will wrap around your phone holding the case in place.
Once the excess carbon fiber is removed, you can begin breaking out your mold. Using a hammer and chisel (or a hammer and flathead screwdriver), carefully break your plaster mold. Do not hammer too hard or you will puncture the front side of your phone case.
Carefully work to remove all of the plaster from your case. This will take some time to do properly, and all of the plaster may not come out if too much epoxy was used. In my case a small amount of plaster was left in one of the interior corners, though it did not affect the finished product. Wash with water frequently to better see your progress.

Step 6: Shaping Your Phone Case

Now that your phone case is flying solo, it is time to shape your final product. Using an X-acto knife, mark all areas that need to be cut from your case. To do this, compare your original case to your current product to see what areas need to be removed. This will include: a hole for your camera and phone light, holes for your charging port and auxiliary port, gaps in the border of your phone case, and any additional holes that are present (such as the middle one for the apple logo).
Carefully cut away these portions with your knife. It is okay if the cuts are not perfectly straight at this moment as we will sand these in just a moment. However try to cut these as straight and close to where you want them to be as possible.
If you happen to cut through any part of your phone case, do not panic as these cuts can be somewhat sealed up in your finished product. I accidentally cut the lower portion of my phone case when I was cutting out the charging port hole, but it was sealed by the final epoxy.

Step 7: Adding Your Finishing Touches

Once your phone case resembles your original product, it is time to put the finishing touches on it. Using a Dremel sanding tool (or sandpaper if you do not have one, though this will take more time), sand down all of the cut edges of your phone. At this point you will be able to smooth any rough edges and make your circular cuts beautiful.
Be aware that carbon fiber does not sand as well as it cuts, so do not try to significantly widen or extend of previous cuts during this time. If you need to cut additional pieces go back to the previous step and use your X-acto knife.
At this point you are able to leave any hidden messages in your phone case. Using the tip of your Dremel tool, you can inscribe messages into the interior side of your phone case. Be careful not to press too hard or you will rip though to the other side, but the sanding tool will roughen the carbon fiber enough to write with. These messages will not be apparent normally, but when finished you will be able to see them when viewed from the side while shining a light. It's the perfect way to inscribe your phone case for yourself or to send a message if your plan to give this as a gift!

Step 8: Making It SHINY

It is now time for the final step in the process!
If you are happy with how your phone case looks at this point, you are ready to seal it in and make it shine!
Mix your glossy epoxy in the same way as before, paying close attention to the instructions on your bottles. This epoxy should be more flexible than the first and promise a glossy finish.
Using a new epoxy brush, apply a coat of epoxy to the exterior surface of your phone case. Applying too much epoxy at this point will lead to globules on your finished product where the epoxy tried to drip off. Smooth any bubbles at this point.
Lay your phone onto a semi-flat surface where it can dry. You can use a larger cup, such as the bottom surface of a red solo cup, to do this. Using a small paper cup might leave a ring around your case where it was placed on the cup.
Leave your phone case to dry until the epoxy is fully set. This might take anywhere from 1-3 hours depending on the type used. (We used a 30 minute epoxy and let it sit for an hour.)
Once dry, you can safely handle your case without gloves and see your finished product! Any lumps of epoxy can be removed by sanding afterwards.

Step 9: Using It With Pride

Congratulations! You now have your very own carbon fiber phone case! Use it with pride and show off to all of your friends your skills!
At this point you may notice how my phone case did not turn out exactly like the one I started with. Unfortunately I did not have the original case when I was cutting mine out, and so had to make all of my cuts from memory. This didn't go quite as nicely as I had hoped, but structurally it works just great!
While you may be thinking that a Carbon Fiber phone case will keep your phone from harm, do not use this as a replacement for an otter box or other protective case. You will be able to feel how flexible your case is, which should indicate that it is not going to save your phone from an impact.
What you will notice though is how sleek and shiny your new case looks! You can now show all of your friends and family your stylishly crafted masterpiece!
Warning: After viewing, friends and family may request carbon fiber phone cases for birthdays, holidays, weddings, president's day, Tuesdays and any other day that might require gifts. At that time feel free to come back and use this tutorial again!