Carbon Fiber Cell Phone Case

This case was made using carbon fiber, epoxy layup and vacuumbagging.

The materials you will need for this project are:

-Vinyl Gloves
-Nitrile Gloves
-Eye Protection
-Phone case you want to mimic
-Press 'N' Seal (Glad)
-Plaster of Paris
-Popsicle stick (or other fine sanding tool)
-Wax Paper
-Tape
-Carbon fiber woven fabric
-FibreGlast 2000 Epoxy Resin
-FibreGlast 2000 2 hour hardener
-Paint brush or sponge
-Vacuum Bag
-Vacuum Bag tape
-Bag attachment for vacuum
-Vacuum pump
-Dremel
-Dremel Blade attachment
-Hammer
-Tweezers
-Dremel sanding attachments (large and small)
-Dremel polishing attachment

Note on Safety: Make sure to always wear eye protection and appropriate gloves. Carbon fiber is an irritant and can affect skin and eyes. Some of the chemicals used for this project are toxic and require special disposal.

Step 1: Creating the Mold: Prepping Your Case

Materials:
-Phone case you want to mimic

-Press 'N' Seal (Glad)

Take your desired phone case and use press and seal to cover the interior. Make sure that there are no wrinkles bumps etc. as these will appear in your final mold. As you can see in these pictures I pushed the press and seal through the holes where the buttons and cameras are located. The purpose of this will be discussed later, but long story short, I did not find this technique effective so don't worry about doing this. Work on making the interior coating as uniform and flat as possible.

Step 2: Creating the Mold: Pouring the Plaster

Materials:
-Plaster of paris

Before beginning this step cover your work area. I suggest plastic wrap but you could also use newspaper or paper towels for this step.

Mix plaster of paris according to instructions. Pour into your coated phone mold and leave to dry overnight. Make sure that the plaster gets into every corner and edge. An imperfect mold means an imperfect case.

IMPORTANT SAFTEY NOTE: Always wear vinyl gloves (or other compatible gloves) and eye protection when handling plaster. The plaster dust is an irritant and it important to protect yourself.

Step 3: Creating the Mold: Perfecting the Mold

Materials:
-Popsicle stick (or other fine sanding tool)

Remove the plaster from the phone case and sand smooth. I used a standard wooden popsicle stick to do this. Any bump that remains in your plaster mold will appear in your final phone case. Essentially you want a mold that has the same size shape and texture as the phone you are planning to put in your case. Remember, your case can only be as good ask your mold is so take your time with this step.

As you can see in my mold I left protrusions where the case should contain holes for the camera buttons etc. The reason I did this was to create a clear bump where the case would eventually need to be cut to leave holes. However, in the end I found these bumps to hinder the wrapping processes in the following steps. I would recommend making your phone as uniform and smooth as possible and worry about measuring out space for the holes later.

Step 4: Carbon Fiber Layup: Wax Paper Wrapping

Materials:
-Wax Paper
-Tape

Wrap your plaster mold in wax paper and use tape to hold. I found the most effective way to do this was to wrap it like a birthday present, folding each corner over and then the triangle down. Again, the better your mold is wrapped the better the case will turn out. If you have large creases or wrinkles these will appear in your final product.

IMPORTANT: do not place tape anywhere you need to lay carbon fiber. In other words, only tape on the "screen" area of your mold. You will need to paint epoxy everywhere your carbon fiber is going to go and this epoxy will take all the sticky-ness out of your tape. If this happens your mold will be impossible to complete.

Step 5: Carbon Fiber Layup: Cut Your Carbon Fiber

Materials:
-Carbon fiber woven fabric
-Tape

Lay your mold on top of your carbon fiber woven fabric and tape off a square area that is just large enough to cover the back of your mold and fold over the sides of the mold by about 1/4 of an inch. You will need less than you think. Overwrapping the mold makes later steps more difficult so only use what you need.

After taping off the appropriate sized section cut it out always cutting through the center of the tape you laid down. Cutting through the tape rather than around it keeps the ends of the carbon fiber weave from fraying and makes your job much easier.

IMPORTANT SAFTEY TIP: Always wear gloves and eye protection when handling carbon fiber. I would suggest a lab coat or long sleeves as well. Carbon fiber is incredibly irritating to the skin and once the tiny fibers get into your skin they are incredibly hard to remove.

Step 6: Carbon Fiber Layup: Warp Your Mold

Materials:
-Tape

Wrap your mold in your carbon fiber square using the same method as you wrapped with wax paper. Try to make the corners as smooth as possible. If you would like you can lay down tape on the inside edge of your mold and make small cuts to help you with wrapping, although in the end i found this made the wrapping process more difficult. Again, tape your carbon fiber weave to the mold but be careful to tape where you can avoid putting epoxy.

As you can see some of my edges frayed. This occurred because I attempted to make small cuts at the corners so they would lay flatter. This technique seemed to work for some people but I struggled with it so give it a try at your own risk.

Step 7: Carbon Fiber Layup:Mix Your Epoxy

Materials:
-Nitrile gloves (or other compatible gloves)

-FibreGlast 2000 Epoxy Resin

-FibreGlast 2000 2 hour hardener

Mix your epoxy according to the instructions on the epoxy you have purchased. In the case of this epoxy the ratio is 3 parts resin to one part hardener.

IMPORTANT SAFTEY NOTE: The safety data sheets for both the resin and hardener are attached. Briefly, always wear nitrile gloves (or other compatible gloves). Uncured epoxy resin is very toxic and cannot be thrown in every day trash because of its toxicity. Allow any mixed epoxy to dry completely before throwing away or throw any uncured epoxy resin away in appropriate hazardous waste receptacles.

Step 8: Carbon Fiber Layup: Impregnating With Epoxy

Materials:
-Paint brush or sponge

work epoxy into carbon fiber fabric until it does not absorb any additional epoxy. A good trick is to work in as much as you can let your case sit for about 10 minutes and try again. The carbon fiber can soak up a lot of epoxy. Be careful to avoid saturating tape but make sure that epoxy is work in over the entire area that will be a part of your final case.

Step 9: Vacuum Bagging: Set Up

Materials
-Vacuum Bag
-Vacuum Bag tape
-Bag attachment for vacuum
-Vacuum pump

Tape one end of your vacuum bag shut with vacuum bag tape. Ensure that there are no wrinkles or holes as this will disrupt obtaining a good seal.

Poke a hole in the center of your vacuum bag and screw in the vacuum bag attachment.

Place your phone inside of the vacuum bag. Of possible place your phone in the corner of the vacuum bad as this will help shape your case. Any additional epoxy is pulled towards the center attachment so the closer your phone is to this piece the more likely it is to be coated in excess epoxy.

Once your phone is inside tape the opposite end of the bag in the same manner that you taped the first end.

Step 10: Vacuum Bagging

Attach Vacuum and Turn on. Try to push out any bubbles that you see stuck on or around your case. If the vacuum doesn’t seem to be working, ensure that you have good seals on both tapped ends as well as at the attachment. Allow the vacuum to run for a full two hours that way your epoxy will be completely hardened when you remove it.

Step 11: Shaping Your Case: Removing Excess

Materials:
-Dremel
-Dremel Blade attachment

Excess epoxy was coated over my case during vacuum bagging. To reach the plaster mold, I had to cut a square of epoxy from the front of my case where the screen should be positioned. I cut out a square using a dremel with the blade attachment and removed this square.

NOTE: if you look on the left of the first image you can see my case bowing out. This is due to two things. First, there was a bump in my mold there so it was difficult to wrap tightly. This is why I don’t suggest leaving these protrusions. Second The tape in this area became saturated with epoxy and stopped holding my carbon fiber. Be careful with the epoxy and tape.

IMPORTANT SAFTEY NOTE: Always have your hair tied back and hands free of loose clothing when using a dremel. Wear eye protection. Never change the dremel bit while the dremel is plugged in and always dremel away from you.

Step 12: Shaping Your Case: Cracking the Plaster

Materials:
-Hammer
-Tweezers

Using a hammer crack your plaster mold and remove the plaster in chunks from your case. Use tweezers to help you remove small chunks from corners and any wax paper that gets stuck behind. Be careful about rubbing the plaster into your case. Once the dust gets in the fibers it won’t come out.

Step 13: Shaping Your Case: Holes

Materials:
-Dremel sanding attachments (large and small)

-Dremel polishing attachment

Using a dremel, create holes for the screen, camera, buttons, headphone jack etc. Use a sanding tool to smooth these holes down after creating them.

NOTE: My case had an uneven coating of epoxy due to the vacuum bagging. I tried sanding it off with the dremel sander but didn’t really find this effective. I'm sure there are better tools for the job than the one I was using but eventually I just decided to leave the slight unevenness.

Step 14: Finishing Touches

Materials:
-Epoxy mix previously used
-Brush

Using the same epoxy formula as before create a top coat over your entire phone. This will give your case a beautiful glossy finish and help smooth over any rough or frayed edges from dremeling. Allow this epoxy to dry overnight and your case is finished!