DIY Carbon Fiber Onewheel Fender

In this project, we'll show you how we made a carbon fiber fender for our Onewheel.

The steps will cover how to make a fiberglass mold from an existing fender that is later used to lay carbon fiber mat sealed with an epoxy resin infusion process.

It's a lengthy process, but the end result is super satisfying, so stick around :)

You can also watch the whole build video in the link above.

Supplies

The items we used are:

(Please note these are affiliate links where we earn a commission at no extra cost to you. It helps us make more projects like this, so thank you for your support!)

Carbon Fiber Fabric: https://amzn.to/3kiHiSD

Chopped Fiberglass Mat: https://amzn.to/33AltrU

Total Boat 5:1 Epoxy: https://amzn.to/33ynx3x

Modeling Clay: https://amzn.to/33ynx3x

Clay shaping tools: https://amzn.to/33ynx3x

Water Based PVA film: https://amzn.to/33ynx3x

Nylon Vacuum bagging film: https://amzn.to/33ynx3x

Silicone Flow media: https://amzn.to/33ynx3x

½” Vacuum T Fitting: https://amzn.to/33ynx3x

½” Spiral Wrap: https://amzn.to/33ynx3x

½” Vacuum Tube: https://amzn.to/33ynx3x

Vacuum Pump Kit: https://amzn.to/33ynx3x

Chip brushes: https://amzn.to/33ynx3x

Tacky Tape: https://amzn.to/33ynx3x

Plastic Pry Tools: https://amzn.to/33ynx3x

Epoxy pigment: https://amzn.to/33ynx3x

Foam Core Board: https://amzn.to/33ynx3x

Seaming Tape: https://amzn.to/33ynx3x

Step 1: Clean and Prep the Original Fender

First, we needed to create a mold of the fender. We wiped down the original fender using an all purpose cleaner and microfiber cloth. Then we doubled back with denatured alcohol.

We applied a few thin layers of PVA, allowing about 30 minutes to dry between each coat. This forms a protective barrier to prevent epoxy from sticking to the fender later.

Step 2: Mold Prep

Setting the fender aside to dry, we covered one side of some foam core with seaming tape. You can also use packaging tape or anything that has a glossy surface. We cut and hot glued the foam core around the edges of the fender to create a lip for the mold.

We chose to make a single piece mold, mainly due to lack of experience. It would have been much better to make a 2 part mold split along the length of the fender for easier de-molding later on.

You can check out this video to see how to make a proper 2 part mold: https://youtu.be/z6gbHq8MGNE

Step 3: Seal the Seams

This will serve as the base for the first epoxy layer, so it’s important to close up any gaps and holes so the epoxy doesn't seep through. We used modeling clay and scraper tools to maneuver clay into the crevices and smooth out the transitions.

You can also use wax, but we found that modeling clay was easier to source locally for some reason.

Step 4: Seal and Epoxy the Mold

We applied a few thin layers of PVA again, with time to dry between each layer. Next, we mixed 2:1 epoxy resin with a splash of blue pigment for contrast and gave the fender a glaze.

Dye would have been better than pigment for uniform coverage because the pigment pooled around the low spots. Alternatively, you can use Gel coat instead of epoxy resin.

Step 5: Laying Fiberglass

When the epoxy became tacky to the touch, we laid shreds of mat fiberglass around the surface of the fender and foam core. The hand torn fiberglass was much easier to overlap and mold than whole pieces.

Each layer of fiberglass was also soaked in a coat of epoxy. We found that dabbing our paintbrushes worked better than stroking to get the air bubbles out

Step 6: Demolding the Fender

We laid 3 layers of fiberglass and let it dry overnight. Once set, we trimmed the excess edges of the fiberglass with a scissor and dremel tool. Epoxy had leaked around the edges of some areas causing it to "lock" the fender to the mold, so we gave it a quick sanding with 80grit to reveal the seam. Then we removed the foam core and after some light hammering and prying, we separated the original fender from the mold.

Now that the mold was ready, it was time to make a new fender!

Step 7: Clean the Mold

We started with a clean slate by wiping down the mold with denatured alcohol. Next, we lined the edge of the mold with masking tape so the tacky tape can have a good place to stick to later on.

Step 8: Epoxy the Mold

Then we brushed on a few thin layers of PVA waiting 30 mins between each coat as we did before. After mixing some more epoxy, we painted on a thick layer into the mold.

In hindsight, we should have used 5:1 epoxy with a slower cure time to give us time to fiddle around with the vacuum bagging process.

Step 9: Laying Carbon Fiber

As this dried, we lined the edge of the mold with tacky tape and cut the carbon fiber pieces to size. About this time, our epoxy became tacky so we carefully laid down the first carbon fiber layer. We covered the first layer with adhesive spray before laying down the second and third layers of carbon fiber, making sure to interlock the weaves between each layer.

We really should have laid the carbon fiber without the first layer of epoxy and let the resin infusion process take care of the coverage because the time it took us to lay all the carbon fiber material and set up the vacuum bag cured the epoxy unevenly against the first carbon layer.

We think the best order of operations is: to apply PVA - then lay the carbon mat with a spritz of spray adhesive between each layer - then set up the vacuum bagging process allowing resin to saturate all of the carbon fiber at once.

Step 10: Peel Ply and Flow Media

Just above the carbon fiber went in a layer of peel ply and flow media. These create a barrier between the carbon and vacuum bagging film, so the epoxy can flow through the carbon weaves without bonding to the film.

Step 11: Vacuum Bagging

This next part was a bit tricky. We placed a vacuum T in plastic spiral hose wrap and taped it along the short ends of the mold on top of the breather material on both sides. Then we place a big sheet of vacuum bagging film over the mold, making sure to seal all the edges with tacky tape.

We made large pleats with extra tacky tape to help crease the film and get into all the nooks. After that, we cut a hole for the vacuum Tees to pop through and sealed the edges with some more tacky tape.

Step 12: Vacuum Setup

We attached vacuum hose to the Tees. One end goes to the vacuum pump while the other end dips into a bucket full of epoxy. We used an empty coke bottle inline of the pump and mold to catch excess resin as it sucked through the mold. We recommend using a small steel catch can, so it doesn’t crinkle like the coke bottle.

When you first turn on the vacuum, gently form the vacuum bag with your hands around the mold to help it get into the crevices.

Pro tip- make sure you have all the correct vacuum fittings before hand, so you don’t have to run to the store, causing the epoxy to pool at the bottom and cure awkwardly like it did for us….

Step 13: Release the Fender!

After we let the fender cure overnight, we were eager to take everything apart. This process took a while because epoxy had pooled to one side and cured since we lost time maneuvering the correct contraption for the vacuum fitting. Despite that, we primarily used plastic pry bars to get the carbon copy out of the mold.

Step 14: Clean Up the Edges

Then we did some final shaping and sanding with our Dremel tool to get a snug fit to the Onewheel and called it complete.

Step 15: Final Product

Now we have a carbon copy of the fender!

This project was very challenging since it was our first time working with carbon fiber and resin infusion, so there are a lot of imperfections. A wise person once said “Every defect gets respect” #laurakampf. Since the fender is meant to sustain some bumps and scrapes, we’re going to embrace the defects on this one and perfect the process on our next fender.

Thank you for checking out this project. We hope this write up helps you tackle this project yourself!

Happy Making!