This instructable is a step-by-step guide to create a carbon fiber phone case for the Samsung Galaxy S6 modeled on the OtterBox commuter case. Creating a carbon fiber case requires 3 basic steps: creating a plaster mold, laying up the carbon fiber, and finishing the fine details on the case using a Dremel tool. Each of these basic steps is broken into numerous substeps to fully explain how to create the case.
1) OtterBox Commuter Case for Samsung Galaxy S6
2) DAP Plaster of Paris Dry Mix
3) Fibre Glast Develpments Corporation 2120 2 Hour Epoxy Cure
4) Fibre Glast Develpments Corporation 2000 Epoxy Resin
5) Carbon Fiber
6) DREMEL 200 Series Rotary Tool
7) Nitrile Gloves
8) Graduated Paper Cups
9) Plastic Mixing Cups
10) Popsicle Sticks
11) Plastic Wrap
12) Wax Paper
13) Masking Tape
14) 2-inch Foam Paint Brush
15) Firm Credit Card
16) Kevlar Scissors
17) Dust Mask
18) Measuring Tape/Ruler
19) Vacuum Sealing Bag
20) Vacuum for Sealing
22) Screwdriver (any type)
23) Safety Glasses
1) Epoxy cure and resin are hazardous materials. Nitrile gloves and safety glasses must be worn while handling epoxy. Any object that comes into contact with epoxy (aside from the phone case) must be disposed of properly. If epoxy is ingested seek medical attention immediately.
2) Carbon fiber particles will cause skin irritation. Wear gloves and safety googles while handling carbon fiber. Carbon fiber also causes throat and lung irritation. Wear a dust mask and safety glasses while using DREMEL.
3) The DREMEL tool has the ability to cut through skin and even bone if on a high speed. Use caution during use.
Step 1: Plastic Mold Preparation
The first step is to create the plaster mold which the carbon fiber layup will be done on. First, the OtterBox phone case must be covered with a layer of wax paper so that the plaster does not stick to the phone case. Place a sheet of wax paper inside the phone case and use the credit card to smooth it down. Make sure there are no creases because they will cause defects in the mold. Then use the credit card to push the wax paper through the charger and headphone jack holes as well as the indentations for the volume buttons and lock button. Once this is completed, tape down the wax paper to the back of the phone case so it cannot move.
Step 2: Mix the Plaster
Create a cup of plaster to pour into the phone case to make the mold. Follow the directions on the plaster container for appropriate plaster mix to water ratio. Use a Popsicle stick to mix the plaster until all of the dry mix has been dissolved and there are no chunks remaining. The resulting plaster should be thick but not chunky. Be sure to make enough plaster to fill your entire phone case.
Step 3: Creating the Phone Mold
Pour the plaster into the phone mold until the plaster reaches the top edges of the phone case. Once poured, pick up the phone case using both hands and lightly drop it evenly back onto the table. Repeat this process several times to ensure the plaster makes its way into the button holes. Let the plaster dry overnight. Once the plaster has dried, remove the mold from the phone case carefully. Be sure not to fracture the mold.
Step 4: Preparing for Carbon Fiber Layup
This step initiates the carbon fiber layup process. Before the carbon fiber can be added, the phone mold must be sanded down using the Popsicle stick. Take the Popsicle stick and rub it back and forth against the edges of the mold to make the edges smooth. This will create a significant amount of plaster dust so either be over a trashcan or perform the work over a piece of plastic wrap. Also smooth down the back of the phone case briefly to ensure that it is level. The final phone mold after sanding down the edges should look similar to the images above.
Step 5: Cutting the Carbon Fiber Sheet
Prior to cutting the carbon fiber,some measurements must be made. Using a tape measure or ruler, measure the back width of the phone mold and the thickness of the mold. The width of your carbon fiber sheet should be equal to the back width of the mold plus two times the thickness of the mold plus an additional 3-cm which provides a 1.5-cm overlap on each side. Then measure the back length of the phone mold (from top to bottom). The length of your carbon fiber sheet should be equal to the back length of the mold plus two times the thickness plus an additional 3-cm as well. On the carbon fiber, measure out a rectangle with these length and width dimensions. Then, add masking tape around the perimeter of this rectangle. Then, cut the carbon fiber on the outer half of the masking tape using the Kevlar scissors. Cutting the carbon fiber on the masking tape ensures that carbon fibers will not become loose. Your final carbon fiber sheet and phone mold should look like the picture above.
Step 6: Preparing for Carbon Fiber Layup Continued
First, coat the phone mold with a sheet of wax paper and tape the wax paper to the front of the phone mold. Then wrap the phone mold in the carbon fiber. To wrap the phone mold, first tape down the longer sides of the cut-out carbon fiber onto the mold. Make sure the overlap on the front of the phone mold is even on both sides as seen in the above image. Make sure the newly applied tape is not touching the carbon fiber - it should only touch the preexisting tape. The next step is taping down the top and bottom of the carbon fiber to the phone mold. This should be done in a manner similar to wrapping a gift box. First, fold in the corners towards the phone mold. Then, fold down the top of the carbon fiber and fold the bottom the fiber on top of the phone mold. Then, tape this down to the phone mold making sure to only apply the tape to the preexisting tape. Once the carbon fiber is taped down snugly to the phone mold as seen in the above image, you are ready to add epoxy.
Step 7: Applying Epoxy
First you must prepare yourself and your workstation for working with epoxy. Put on nitrile gloves and tape down a large section of plastic wrap to your workstation to avoid epoxy contamination. Then begin mixing your epoxy. The epoxy mixture is 3-parts resin to 1-part cure by volume. Use the graduated plastic cup to measure out approximately 45-ml of resin. Using the Popsicle stick, pour the resin into a larger plastic cup. Then, pour out 15-ml of epoxy cure into another graduated plastic cup and slowly add this cure to the larger plastic cup while mixing it in slowly with a Popsicle stick. If bubbles begin to appear in your epoxy, you are stirring too quickly with the Popsicle stick. Once the epoxy is mixed, begin applying it to the entirety of the phone mold using the 2-in foam brush seen above.The entire back and sides of the mold should be coated in epoxy and the front portion of the mold up to the tape should be coated as well. One way to accurately coat the sides of the phone mold is to place it on top of a plastic cup as shown above. Once the phone is adequately coated in epoxy, it is time to vacuum the phone mold. Be sure to dispose of all materials that touched uncured epoxy properly.
Step 8: Vacuuming the Phone Mold
First, open up your vacuum seal-able bag and place your epoxy-coated phone mold inside of it. Place next to one of the edges of the bag for best results. Then, seal the bag and attach the vacuum to the bag. Turn the vacuum on. While the vacuum is running, smooth down the bag around your phone mold to make the vacuum as tight as possible. Allow the vacuum to run for at least 2.5 hours. When done, turn off the vacuum and remove it. Then open the bag and remove your phone mold. This ends the carbon-fiber layup process.
Step 9: Removing the Plastic Mold
This begins the process of finalizing the carbon fiber phone case. The first step is to remove the plaster from the case. First, put on safety glasses. Then, remove the tape that is holding the carbon fiber to the phone mold. If tape will not come off, skip this step. It can be removed later. Hit the plaster with the hammer until it begins to crack. Once it cracks, use the screwdriver to wedge chunks of the plaster out of the phone mold. Repeat this process until all plaster is removed from the case. Be careful - applying too much force can fracture the phone mold. Your phone case should look like the above image once all plastic is removed. Once the plaster is gone, scrape off the wax paper and any existing tape within the phone case. Leave the tape on the top of the case alone - it will be removed later. If all wax paper cannot be removed (as seen in above image), do not panic - it only affects the aesthetic look of the inside of the mold and will not affect usability or strength of the phone case.
Step 10: Using DREMEL to Finalize Phone Case
The DREMEL tool is used to cut through the carbon fiber in order to create the holes for the headphone jack, charging port, and speakers. It is also used to cut off the tape on the top of the phone case. Please consult the DREMEL user manual if you are unsure how to operate the tool. Attach the cutting fixture (first fixture in the second image) to the DREMEL. Make sure you have gloves and safety glasses on as well as your dust mask. Put a layer of plastic wrap down on your workstation to avoid carbon fiber contamination. Turn the tool to a medium speed and cut around the edges of the tape on the top of the phone case as seen in the third image. Once the tape is removed, it is time to create all of the holes in the case using the second tool in image two. Use the DREMEL to create the holes for the headphone jack, charging port, and speaker on the bottom of the case (fourth image). Then create the hole for the volume buttons on the left side of the case (fifth image), the hole for the speaker on top of the case (sixth image), the hole for the lock button on the right side of the case (seventh image), and finally the large square hole for the camera on the back of the case (eight image). Once all cuts have been made, use the side of the same tool used to create holes at a low speed to buff the portions of the case where cuts and holes were created. This will smooth the cuts and ensure that no parts of the case are sharp to touch.
Step 11: Final Coat of Epoxy
The final step is to add a final thin coat of epoxy to the phone case to provide a glossy finish. Consult step 7 for instructions on mixing the epoxy. Apply a thin coat of epoxy to the entire outside of the phone case and let it dry on a piece of wax paper. Make sure you are wearing nitrile gloves. Once the final coat of epoxy dries, your phone case is finished! Be sure to dispose of all materials that touched uncured epoxy properly.