There are certain personal safety precautions that ought to be taken during the course of this project. Vinyl gloves and goggles should be worn at all times. Jeans and closed toed shoes are also recommended. Long hair should be pulled back and away from the face. For all steps including carbon fiber, it is highly recommended that long sleeves be worn to prevent carbon fiber from getting into your skin. Also be careful to clean everything that comes in contact with the epoxy. Remember, epoxy is forever. Enjoy making your cell phone case!
1:1 Fibre Glast brand with 2000 Epoxy Resin and 2120 2 Hour Epoxy Cure
- 1:1 General Purpose Epoxy Hardener and Epoxy Resin
- Disposable epoxy brushes (sponge brush)
- Disposable mixing tools (popsicle sticks)
- Disposable mixing cups (red solo)
- Plastic wrap
- Exacto knife
- Masking tape
- Sharp scissors
- Vacuum bag, vacuum seal, and vacuum
- 1:1 Ratio Plaster of Paris
- Woven carbon fiber
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Preparation
In order to control the mess and ensure a safe and easy clean up, there are simple tips to keep in mind.
Lay your work area down with a flat, disposable material. We used plastic wrap and tape.
After mixing and using the epoxy, keep all of the disposable materials that came in contact with the epoxy out on the covered work space to dry completely before disposing.
All materials used are non-toxic and may be thrown out as landfill trash.
Step 2: Choose Your Cell Phone Case
To start, you will need another cell phone case to use as your mold. A stiffer case will be better to hold your plaster with as opposed to a flimsy case. A simple case is shown in the picture. With two piece cases, it is best to use the stiffer piece instead of the rubbery piece.
Step 3: Lay Out for Mold
Lay out the Press N Seal Cling Wrap over your empty cell phone case. Press the wrap down and be sure it is secure along the edges, sides, and corners. Try to make sure the paper is flat and sticks out of all adapter holes on the case to preserve this indentation for your mold. Also try and get rid of all of the wrinkles as big wrinkles will affect your carbon mold.
Step 4: Making the Plaster
Next you will create the plaster to create a mold of your cell phone case. Mix your plaster using a ratio of 1:1 plaster and water. Stir for a minute. The ideal consistency is similar to that of pancake batter.
Step 5: Making Your Mold
Pour plaster into your cling-wrapped cell phone case. Be sure not to wait too long between mixing and pouring or your plaster will harden too much to be used for your mold! The example in the picture is not the best. You can clearly see some lumps in the plaster. However, this does not matter as long as it is smooth on the back of the plaster.
Step 6: Curing the Plaster
Let your mold cure, or dry, for the required time. For the plaster I used, this was approximately 30 minutes. The length of this time will vary depending on the type of plaster you use. If your plaster does not dry, something has gone wrong with your ratios. To ensure you have a good mold, it might be best to scrap that plaster and try again by remixing your plaster and using less water.
Step 7: Separating Plaster
Pry the cling wrapped mold out of the cell phone case. Discard the cling wrap. This should leave you with a good mold of the cell phone case. If the holes and bumps for the adapters and buttons did not come out, you can outline their approximate location on your mold with a Sharpie so you know where to cut once the carbon fiber is laid. Use sandpaper to smooth out the wrinkles and jagged edges on the sides and back of the mold. The smoother the plaster, the more uniform the carbon fiber will lay.
Step 8: Carbon Fiber Cut Out
Cut a swath of carbon fiber that is ample enough to cover the back and sides of your mold. In this instance, there is such a thing as too much. An excess amount of carbon fiber will only hurt you in this process.
Step 9: Creating Carbon Fiber Mold
Cover the back and sides of the mold with epoxy so you can attach the carbon fiber to the phone mold. The ratio used here was 1:1 parts epoxy resin to hardner, stirring for a minute in a folding motion to fully incorporate both parts and eliminate bubbles. I used the Fibre Glast brand with 2000 Epoxy Resin and 2120 2 Hour Epoxy Cure as shown in the picture. Fold the excess carbon fiber over the phone case sides to the front of the mold. You can either fold the corners like the way you would make a bed or cut out the corners so there is less of a bulge when you fold over the sides. In my example, I cut out the corners. Wrap the epoxy soaked carbon fiber with a sheet of wax paper to help the material retain the epoxy.
Step 10: Vacuum Bagging
The next step is to vacuum bag the plaster and the carbon fiber. Lay your case inside a vacuum bag. Seal off the bag with a special vacuum sealer, a kind of tacky tape. Insert the vacuum line but make sure to seal as close to the vacuum line as you can to ensure there are no holes. Vacuum for 2 or 3 hours until the epoxy dries. If there is a hole in your bag, you will be able to hear a whistling noise. Find the source of the noise to find and fix the hole by covering it with tacky tape. The picture shows how the cell phone case should look after the vacuum bagging has completed.
Step 11: Removing the Plaster
After the epoxy has dried, the next step is to pry the mold out of the carbon fiber. This can be achieved by using a screwdriver and a hammer. Hit the hammer to the top of the handle of the screwdriver to apply pressure and crack the mold. Be careful not to hammer too hard as this can create holes in your carbon fiber. Chip out all pieces of your mold from the carbon fiber case. To help clean the case afterwards, you can wash it using soap and water.
Step 12: Cutting Your Case
The only remaining steps are to make sure your case will not impede your cell phone functions.
Trim all excess carbon fiber. This can be done using either a dremel tool or shears. Also cut out the holes the case needs for charging adapters, buttons, headphones, etc. I was able to cut mine out using a cheap exacto knife. I also used a dremel with a sanding bit to tame the jagged edges left from all of the trimming. The attached pictures show the fine detailing process.
Step 13: Finishing Your Case
Your cell phone case is nearly complete!
Make sure your cell phone case is clean from any plaster fragments or dirt that you wouldn’t want to be seen in the finished project. Thoroughly dry the case from cleaning. Next mix the same 1:1 epoxy resin to hardner ratio as used before. I used the General Purpose Epoxy Hardener and Epoxy Resin. Not much epoxy is needed. Using a sponge brush, coat your cell phone case with the last layer of epoxy to ensure a protective, shiny enamel like finish. After drying, your cell phone case will be ready for you to use!