Carbon Fiber Phone Case

Objective:

To create a Carbon Fiber iPhone 5 cell phone case by casting a plaster mold from an existing case and using a carbon fiber lay up method and fiber glass epoxy.

This method can be used to make a phone case for any type of phone.

Hazards:

Epoxy resin and hardener can cause irritations and harden into fabrics.

Handling carbon fiber may cause irritation to any exposed skin.

Dremel tool is very sharp and can be dangerous to use.

Precautions:

To prevent skin irritations, vinyl gloves should be worn as well as safety glasses. It is suggested to wear long sleeves and pants to prevent contact with stray carbon fibers.

Sources of Error:

Improper measuring of epoxy, bubbles in either the mold or epoxy, not fully impregnating the carbon fiber with epoxy, and leaking seals on vacuum are the most common sources of error

Note:

Brand named products were what was used, equivalent products may be interchanged

• Phone case (iPhone 5 case was used)
• Plaster powder (DAP)
• Water
• Popsicle sticks
• Glad ClingWrap
• Saran Wrap
• Gloves
• Safety glasses
• 3 oz cups paper
• 16 oz cups plastic
• Fibre glast Epoxy resin
• Fibre glast Epoxy hardener
• Carbon Fiber sheet
• Tape (masking)
• Wax paper
• Foam paint brush
• Vacuum bag and nozzle
• Fiber Glast adhesive strips
• Vacuum pump
• Vacuum pump hose
• Screwdriver and/or hammer
• Paper towel
• Tweezers
• Gloss final coat
• Dremel power tool with blade, sanding bit, and rough drill

• cover work area in Saran wrap (creating the mold will often lead to dust and plaster so it is best to keep electronics away)
• place phone case down and tightly line the inside with ClingWrap
  • If there are any holes (for the camera, charging port, etc.) it is good to push the ClingWrap through those holes slightly so the mold has a bump in that location
• Mix the plaster in accordance to the ratio given by the company. For DAP it is 1 part by volume water to 2 parts DAP plaster.
  • It is best to put them separately in the 3 oz cups then pour them in the 16 oz cup to stir
  • When stirring, avoid making bubbles as they can lead to a deformation in the mold
• Pour liquid plaster into the ClingWrap in the case and make sure it is filled
  • Use the Popsicle stick to flatten out the surface and push out any bubbles that may be seen
• Wait 24 hours for the plaster to harden
• Once hardened, remove from case and ClingWrap
• Sand down any sharp or extra edges with a Popsicle stick
  • The face of the mold where the phone screen is does not need to be sanded as it does not affect the case

• Cut wax paper to be able to fold over on all sides and have at least 1/2 inch extra covering the front side of the phone mold
• Cut the carbon fiber to be of a similar size
  • when cutting the fiberglass, tape the section that you want to cut first then cut in the middle of the tape. This prevents fraying.
• Tape down the edges along the long side of the mold first
  • while taping here, do not get any of the tape on the carbon fiber as once it is epoxied it is impossible to remove without damaging the phone case
• Fold over the shorter ends and tape them to the previous tape that was laid
• Make sure carbon fiber is snug or case will not fit to the mold thus not fitting to the phone

• Prepare ratio of resin to hardener instructed by epoxy each in their own 3 oz cup
  
  • For Fibre Glast Epoxy it was 3 parts by volume resin to one part by volume hardener
  • Only a total of approximately 4 oz will be needed to cover most phone cases
• Mix the resin and hardener in a new plastic 16 oz cup stirring slowly to not create any bubbles
  • The resin usually is to be poured first followed by hardener
  • Pour slowly to prevent any bubbles

• It is best to place another layer of Seran Wrap down to prevent any debris from making the epoxy/mold to get on phone case
• Place the phone case tape down on the Seran Wrap with the majority of the carbon fiber facing up
• fill the tip of the foam brush with the epoxy and dab it into the carbon fiber
  • dabbing it in is important to make sure it is pushed into all layers of the carbon fiber all the way down to the wax paper
• Make sure to fully impregnate the sides on the phone case with epoxy as that is often ignored
• DO NOT get epoxy on the tape
  • it is okay to not completely get it down to the tape on the face side of the phone case as most of that will be cut away later. This will help avoid getting it on the take which makes it extremely difficult to remove later
• Once done brushing in the epoxy it is recommended to place on top of cup in (look at second picture in step) while preparing next step to avoid creating a epoxy puddle in work area leading to uneven epoxy

• Cut small hole in center of bag and attach nozzle
  • Make sure it is very tight to prevent leaking
• Place phone case in vacuum bag with the tape facing down
• Once phone case(s) are placed in vacuum bag use Fiber Glast adhesive strips to seal both sides
  • Use approximately an extra 1/2 inch of strip on each end to fold over itself to make sure the corner is filled
  • Press in very securely to prevent leaks
• Attach the hose to the nozzle and turn on the vacuum
  • Look for any leaks that could be breaking the seal and attempt to press them out
  • Allow the vacuum pump to remain on until epoxy sets (usually about an hour remaining for 2 hour epoxy)

• Once cured remove the phone case from the vacuum
• The next steps will create a lot of dust and debris so it is best to cover work area in Seran Wrap as well as any electronics near by
• remove the tape that was holding down the sides
  • It is okay if this causes fraying as that will be removed later
• Use the screwdriver or hammer to create cracks in the mold and pry out the pieces
  • The epoxy is strong enough to take moderate hits from the hammer to break the mold or you can hammer the screwdriver into the mold
  • The wax paper should come out with the mold but remove any remaining paper that may be left behind with tweezers
• Once all of the mold is removed, use a moist paper towel to get rid of the dust
• The Seran Wrap over the work area can be used to gather all of the dust and pieces and thrown away then re-lay more plastic

• Place the phone case open side up
• Use the blade piece of the Dremel tool to cut the edges down to the side of the phone case that is being modeled
• Use the rough drill bit to cut out all openings for the camera, power port, etc
• Use the sanding bit to smooth out the edges of the phone case

• Once phone case is cut, add clear final thin coat of epoxy to hardnen the outside
• Let clear coat dry

• Your phone case is ready to go after about 24 hours!!!