Objective

To show how to make a cell phone case out of a carbon fiber sheet and epoxy with the use of a plaster phone mold. The cell phone case used in this case is for a Samsung Galaxy S5 smartphone.

Hazards

Chemical hazards can arise from the epoxy used. Epoxy can cause irritation. Be careful of the clothing you wear to avoid getting epoxy on them. Carbon fiber can also cause skin irritation. To protect against these, make sure to use the proper gloves based on the glove chart There are also mechanical and electrical hazards from any tools used.

Step 1: Get the Materials Needed

Plaster Phone Mold

Samsung galaxy S5 phone case
Plaster Powder (Brand used: DAP)
Plastic sealing wrap (Glad Press'n Seal)
3 oz paper cup (Dixie)
16 oz plastic cup
Water
Saran wrap
Wooden craft stick
Gloves

Carbon fiber phone case

Samsung galaxy S5 plaster phone mold
Carbon fiber sheet
Fiber Glast Epoxy
Foam paint brush
Saran wrap
Masking tap
Wooden craft stick
Wax paper
3 oz paper cup (Dixie)
16 oz plastic cup
Vacuum bag with nozzle attached
Vacuum pump with hose
Adhesive strips to seal vacuum bag
Dremel tool with various attachment heads
Screwdriver
Hammer
Gloves

Step 2: Prepare Phone Case for Plaster

Clean the phone case used with soap and water
Lay out saran wrap on area used and tape down edges
Have the inside of phone case facing up
Use Glad "Press'n Seal" plastic wrap to cover the inside of phone case
Make sure the sealing plastic is smooth and free of wrinkles and bubbles as possible

Step 3: Putting Plaster in Phone Case

Follow the instructions for the plaster on container (2 parts of plaster powder and 1 part cold water by volume)
Use the 3 oz cups to measure out each part needed
Combine plaster and water in the 16 oz plastic cup
Stir with the wooden stick until plaster is smooth
Slowly pour the plaster in the phone case and make sure all parts are covered
Wait 24 hours for plaster to harden

Step 4: Shaping Phone Mold

Once the plaster is harden, carefully remove plaster mold from phone case
Use a wooden stick to shave off rough parts of the mold
Final mold needs to be smooth on all sides and edges before applying the carbon fiber

Step 5: Wax Paper and Carbon Fiber Sheet

Cut the wax paper at least 1 1/2 inches bigger than all sides of the phone mold
Wrap the phone mold with wax paper and tape it together with masking tape
Make sure masking tape is on the "screen" side of the mold
Use tape to mark edges on carbon fiber sheet
Cut the carbon fiber the same size as the wax paper
Wrap the carbon fiber around the phone mold (the corner or side can be cut a little to make this easier)

Note: Make sure the masking tape is not covering the sides or edges of the carbon fiber case. If epoxy gets on the masking tape, it will get stuck to the carbon fiber.

Step 6: Apply Epoxy to Carbon Fiber Phone Case

Measure 3 parts of Fiber Glast Epoxy resin and 1 part Fiber Glast Epoxy hardener by volume in the 3 oz cups
Put the resin in a plastic cup and slowly pour in the hardener
Slowly stir the mixture
Apply the epoxy to the phone case by dabbing
Make sure to get the edges and all sides of the carbon fiber covered with epoxy
Putting the case mold on a cup helps get epoxy on the edges
Avoid getting epoxy on the tape

Step 7: Prepare the Vacuum Bag

Seal one side of the vacuum bag with the adhesive tape
Cut a small hole in the center for the nozzle
Place the phone case in the bag with tape side down
Seal off the open side with about 1/2 inch of the adhesive tape on the top side to properly seal the corner (refer to the last picture)
Firmly press down the tape to ensure it is tightly sealed

Step 8: Vacuum Seal the Phone Case

Attach the vacuum hose to the nozzle
Tape the hose to an area above the bag to stabilize it if necessary
Turn on the vacuum and listen for any leaks
Once all parts are firmly sealed, press down on the case and remove any bubbles
Leave it for an hour and allow the case to dry

Step 9: Get Plaster Mold Out of Carbon Fiber Case

Obtain phone case from the vacuum bag
Case may have excess dried epoxy on the surface (this can be fixed with buffing and coating the top)
Remove tape if possible
Use hammer to crush the plaster mold
Use screwdriver to get plaster out of the edges
Remove all plaster and wax paper from inside the case
Use a wet paper towel to wipe off any plaster on case

Step 10: Trim Edges

Using the Dremel tool with a cutting blade attached, trim the edges to appropriate size
Change Dremel head to a round rod to make necessary holes on the case (the type of head can be seen on the picture of the Dremel)

Step 11: Buffer Case (if Necessary) and Apply Final Coat

Using the buffering tool on the Dremel, buffer off any excess epoxy dried on the phone case
Buffer tool can also be used to smooth edges
Once the phone case looks as desired, apply a final coat of epoxy to get a glossy finish
Wait 24 hours for the phone case to dry

Step 12: Congratulations on Your New Carbon Fiber Phone Case!!!

Enjoy!

Possible Improvements:

Be careful where the trimming blade is when trimming the edges. The blade could cut the back side of the case. Also, put enough epoxy to impregnate the case and prevent dry spots. However, using too much can cause harden excess epoxy on the phone case. When making the epoxy, make sure to use the right ratio and pour the hardener into the resin slowly. Stirring it slowly will ensure that there are minimum bubbles in the epoxy. This will make the final coat on the case less porous.