Since converting a longboard or skateboard to electric will add significant weight, it is necessary to keep all of the components as light as possible to begin with. Carbon-fiber is an ultra-strong, ultra-lightweight composite building material, and it can be used to significantly increase the strength, and decrease the weight of a skateboard deck.
While it might sound daunting to work with carbon-fiber, it is actually very easy with some prior research (it is very similar to fiber-glassing). This deck has plywood supports for the trucks, and an integrated compartment for the electronics, which adds structural support and increases the clearance under the deck.
Additionally, by making your own carbon-fiber deck, you will be saving yourself a lot of money! An already-made carbon-fiber deck for electric skateboard will set you back about $500! If you buy in bulk, this deck costs only about $75, not including labor.
Step 1: Watch the Video Tutorial!
Watch this quick video to learn more about the carbon-fiber deck, and the electric skateboard that it was used for!
Step 2: Build the Foam Core
The first and most important step to making a carbon-fiber skateboard deck is to make your entire deck out of some cross-linked PVC foam. This stuff is far more durable than regular foam, and it going to be necessary to create a light-weight deck (an all carbon-fiber board is possible, but it is not as light).
The foam I used was scrap from my dad's catamaran project; it was 3/8" thick, and it was sold under the brand name "H100 Divinycell Plain, 6lb./cu.ft.". Thanks to fiberglass supplies for providing the materials for this project; those guys are awesome!
In order to make the deck shape, you will need to glue, sand, and carve this foam into the shape you want. The two most important features are the plywood supports around the trucks, and the two long foam pieces of foam that span the length of the deck. The plywood supports are crucial for holding the trucks (if you used just foam, the screws would rip out). The two long supporting pieces of foam (3/8" thick) make up the electronics compartment, but they also add a lot of support!
I assembled the pieces with silicone-based glue and screws at first, and then I took the screws out when the glue dried. The type of glue is not critical to the strength of your deck, since the carbon-fiber is going to hold everything in place, and provide the actual structural support (although the foam helps out a lot!).
I have attached a ton of reference pictures with this step (33). Check them out, words can't explain it as well.
Step 3: Stick the Carbon-Fiber Onto the Foam Core
Use some spray on adhesive to stick the carbon-fiber onto the foam core. I used two layers on top, and two and a half layers on the bottom of the deck (an extra little bit around the electronics compartment). The carbon fiber was this "Carbon/Basalt Dual Twill 12k 20oz 11.5'' WIDE / board building material +". It used to be sold on fiberglass supplies, but now there are only similar fabrics available. I used about 16 feet of this carbon fiber (including excess).
When you use the spray adhesive (I used some 3M drywall adhesive), make sure to get the carbon-fiber into all of the nooks and crannies. It will stretch a lot, but if you do it carefully (wear gloves) it will retain the weave. Again, there's lots of reference pictures in this step.
Step 4: Apply Epoxy
Use a stirring rod to mix up some generic two-part epoxy. The more you mix, the faster the epoxy tends to cure. You are going to need to use about the same weight of epoxy as you have carbon fiber, in order to cover the top and bottom of your deck using a squeegee. Make sure to use plenty of plastic to keep your work-area clean. Do not soak the carbon-fiber, as the vacuum bag will help dissipate the epoxy evenly throughout the deck.
Step 5: Vacuum Bag Until the Resin Cures
After you have distributed epoxy over the surface of the deck as evenly as possible, place the deck in a strong vacuum bag for at least 24 hours. We used a converted air-compressor to make our vacuum, but people have had good results with a manual vacuum pump as well.
Make sure you spread the bag around the deck as evenly as possible. You need to make sure there is good contact on all surfaces and bends, and you don't want too many "epoxy lines" forming after the resin cures. If you want to reuse your vacuum bag, a good tip is to place some paper towel near the suction line/adapter. It will stop any epoxy from being sucked into your pump/opening.
After the resin cures, take the deck out, use a jigsaw to trim the excess, then sand down the entire deck. Don't worry if it doesn't look shiny, you will need a clear coat and polish to make it shiny.
Step 6: Make the Lid
Now that your deck is in it's rough shape, I suggest you make the lid for the electronics compartment before applying a layer of clear coat to the deck (if you are making an electric skateboard, not if it's a regular deck).
In order to make the lid, you must fill the compartment with foam. This doesn't have to be the high-strength foam used for the foam core, it can be regular squishy foam as well. Once you have filled the compartment with foam, sand it down until it is flush, or slightly above the sides of the deck.
Then comes the carbon-fiber again; put a layer of thin plastic on top of the electronics compartment and foam, place 2-4 layers of carbon-fiber and/or fiberglass on top of the plastic, then apply more epoxy (1:1 ratio of weight of carbon-fiber to epoxy), and vacuum bag until cured. This method works with many different composite cloths, and it is similar to vacuum forming plastics.
After the lid is cured, carefully cut it to size using a jig-saw and sandpaper.
Step 7: Drill the Holes/Apply Griptape
The last step are the finishing touches. In order to make your deck and lid shiny, you will need to use fine-grit sandpaper to sand everything down, and then apply several layers of clear coat (I got mine from Home Depot, any generic spay-on clearcoat will do).
Additionally, if your deck does not come out as smooth as you would like it to, you can always sand the imperfections and evenly spread epoxy onto them. This will level out your deck.
In order to hold the lid down, you will need to drill holes through the lid and into the deck. I used metal threaded inserts, and used epoxy to hold them inside the deck. Then it was a matter of attaching a rubber/foam gasket made out of sticky foam to the lid, then securing the lid to the deck with bolts.
You will also need to drill holes for the trucks with a drill, and apply your choice of griptape!
Step 8: V6.0 Fiberglass Deck
As you might have noticed, there were pictures of two decks throughout this Instructable! That's because one deck was covered in carbon-fiber, and the other was covered in fiberglass! The steps to working with carbon-fiber are really similar to the ones for working with fiberglass!
While the carbon-fiber deck is cooler, stronger, and lighter, the fiberglass deck is much cheaper, and I will be using the fiberglass one for my v6.0 electric skateboard! You can see from the images that the fiberglass board has plenty of flex, while the carbon-fiber board has next to none!
You can also use different types/style of fabrics for your build. The cloth above is a type of fiberglass and can be used for decorative purposes!