Introduction: DIY Carbon Fiber Cell Phone Case

By
About: Materials Science and Engineering student.

This Instructable serves a guide for individuals interested in designing and creating a personalized carbon-fiber cellphone case.

Hazards

  • Chemical exposure to un-cured epoxy
    • Epoxy holds the potential to be harmful to the skin, eyes, and nose
  • Set epoxy and carbon fiber
    • Cured epoxy and hardened carbon fiber are incredibly difficult to work with mechanically; epoxy is incredibly difficult to remove once set, while carbon fiber may potentially become sharp and difficult to cut. Handle both with proper care.
  • Dremel
    • Both carbon fiber dust and excess plaster dust are released when using the dremel to add finishing details to your case.

Safety Precautions

  • Follow proper "lab safety"
  • Wear proper personal protective equipment (PPE) when handling epoxy resin and hardener
    • Proper lab-safe clothing, goggles, gloves, etc.
    • Note: Consult a glove chart to ensure gloves are compatible with the epoxy resin
  • Use a mask to avoid breathing in carbon fiber/plaster dust and wear clothing that'll shield your skin, in order to avoid potential skin irritations caused by tiny fibers interacting with your skin.


Step 1: Material Preparation

Comprehensive List of Materials

Personal Protective Equipment:

  • Dusk mask
  • Nitrile gloves for epoxy
  • Vinyl gloves for plaster
    • Note: Check compatibility on glove chart
  • Appropriate clothing/apron

Case:

  • Phone case
    • Note: The phone case doesn't experience any damage, so you shouldn't be hesitant using your own.
  • Plaster of Paris
  • Carbon Fiber
  • Epoxy Resin
  • Epoxy Cure
  • Plastic Wrap

Tools:

  • 16 oz Plastic Cups
  • 3 oz Dixie Cups
  • Plastic Wrap
  • Paper towels
  • Popsicle Sticks
  • Cups
  • Foam Paint Brushes
  • Tape
  • Scissors
    • Carbon fiber specific scissors are most optimal
  • Vacuum/Vacuum bag

Step 2: Making of the Mold

  1. Obtain a cellphone case
    • Ensure that the case properly fits your phone, for it will be the base mold for your carbon-fiber case layup.
  2. Prep your work space
    • Secure your workstation from plaster residue by taping down a sheet of saran wrap.
  3. Tare a section of Glade Press and Seal plastic wrap
    • The piece of plastic wrap (Glad Press'n Seal) should be slightly larger than your phone case
    • Tip: increase all edges of the perimeter by an inch to ensure it properly fits and is easy to later remove
  4. Press the sheet around the inside of the phone case
    • The plastic wrap should be free of any air bubbles/creases
    • Add extra space in areas containing holes (camera hole, charging port, etc).
  5. Prepare your plaster
    1. Pour 3oz of plaster to a large (16oz) plastic cup
    2. Add a small amount of water and stir thoroughly using a wooden popsicle stick
    3. Continue adding small quantities of water and stirring until the plaster reaches a thick, smooth, and easily pourable consistently
  6. Pour the plaster into the previously prepared cellphone case
    • The entire interior of the case should be coated with plaster
    • Smooth and bumps on the surface using a popsicle stick
  7. Let the plaster set without disturbance for 24 hours

Step 3: Remove the Plaster Mold From the Cellphone Case

The Removal

  • After the plaster has set, remove the plaster phone mold from the cellphone case.
  • The hardened plaster mold will cause some difficulties, so it's most beneficial to start at the most flexible part- the corners.

Polishing

  • Smooth down any rough edges using a popsicle stick as your polishing tool
  • Wipe case to remove any excess dust when desired look is achieved

Step 4: Carbon Fiber Mold

Prep

Clean your work station; properly dispose any excess plaster, epoxy, or worn saran wrap.

Secure a fresh sheet of plastic wrap around you work station.

Cutting the Carbon Fiber

  • Measure your phones length and height, then add an extra 1.5 inches to each dimension
  • Tape out said dimensions on a sheet of carbon fiber; this will mitigate fraying edges
  • Cut out the rectangular sheet of carbon fiber, making sure you cut along the middle of the taped edges

Prep the Plaster Mold

  • Cut a sheet of wax paper approximately 1.5 inches longer on all dimensions than your phones true perimeter
  • Wrap it around the plaster mold and tape down the edges to make sure the plastic wrap is tightly attached
  • Leave a gap in the center of the mold; this will enable easy removal in the future

Wrap the Carbon Fiber

  • Wrap the carbon fiber sheet around the phone mold
  • Ensure corners are laid down in an aesthetically pleasing manner
    • Note: You may want to practice various folding techniques using a sheet of paper to decide which method would be best for your phone case
  • Secure the carbon fiber down by taping the edges
    • Avoid getting tape in areas you wouldn't want them when the phone case is fully done; it will be hard to remove these pieces after the case has been coated and vacuumed

Step 5: Coat Your Carbon Fiber Case

Prepare your Epoxy

  • Measure 45 mL of the fiberglass resin into a 3oz dixie cup
  • Measure out 15 mL of fiberglass hardener into a 3oz dixie cup
    • Note: The solution should be 3 parts epoxy, 1 part hardener
  • Transfer the epoxy to a 16oz plastic cup
  • Slowly add the hardner to the epoxy
  • Use a popsicle stick to stir the solution for two minutes

Coat your Case

  • Apply epoxy to the front of the carbon fiber case, using a foam brush
  • Coat all of the edges
  • Place your case on an apparatus (a plastic cup will do), to enable you to coat the back of the phone case
    • Make sure that the case is fully impregnated with epoxy; all fibers should be fully saturated

Step 6: Vacuum Seal

Prepare your Vacuum Bag

  • Cut a sheet from the vacuum bag role, ensuring it's large enough to encapsulate your phone case
  • Cut a piece of vacuum seal tape the length of your previously cut bag, adding an additional inch to the end
  • Remove the adhesive and tightly seal one side of the bag
  • Place the vacuum nozzle and hose attachment in your vacuum bag
  • Cut another piece of vacuum seal tape, identical to the previous length. Attach it to the other end of the vacuum bag, but avoid sealing
  • Place your phone case into the vacuum bag
    • Note: avoid the center; it's most optimal to place the case near the corners or edges
  • Remove the adhesive strip from the tape and seal the bag shut

Turn on the Vacuum

  • Remove any wrinkles by pressing firmly against the case
    • Note: it's best to start from the middle and work your way out towards the edges
  • Securely attach the vacuum hose onto the nozzle adapter
  • Seal connection with additional vacuum bag seal tape
  • Plug the vacuum pump into the wall and turn the power on
    • Note: listen and look for any leaks in the vacuum bag
    • Flatten any potential bubbles on top of your cellphone case
  • Let the vacuum run until the epoxy is dry (this takes several hours) and then remove case

Step 7: Additional Features

Before Beginning

Make sure you have a clean workstation!

Lay a fresh layer of plastic wrap down and get your safety equipement on!

Removing the Plaster

  • Put on a dusk mask
  • Crack the plaster with a hammer and use a screwdriver to remove remnants of the plaster
    • Continue until the core of the case is completely free of plaster

Dremel

  • Use a Dremel to cut holes in the case
    • Examples: camera hole, charging port, volume buttons, etcetera.
    • Note: choose desired heads and speeds to achieve desired look/features

Step 8: Top Coat

Note: This step isn't necessary, but it enhances the overall look of the phone case.

Finish

  • Prepare epoxy using the same formulation as before
    • 3 parts epoxy/1 part hardener
  • Coat your finished cellphone case to achieve a shiny and slick look
  • Let the epoxy cure for 24 hours

Voila! You have created your very own carbon fiber cellphone case!