How to Shape a Foam Mold for Building Skateboards

Picture of How to Shape a Foam Mold for Building Skateboards
Designing your own mold is a fun and effective way to create your own custom skateboard! With Roarockit's Thin Air Press vacuum bag technology, a builder only needs to design/shape one side of the mold. This makes the process a lot easier and more affordable than having to perfectly match a male and female side of a standard concrete or wood mold.

Here are the tools you need:

- Utility knife with a sharp long blade

- Some sort of a saw. I used a Japanese saw, but a regular saw will do.

- Rasp or a surform

- Foam sanding block - cut this from a block of foam. Make it wider than the width of the deck, and glue 100 grit sandpaper or stick grip tape to one side

- pencil or black marker

- A straight edge like a combination square or 12" ruler
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Step 1:

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Once you have laid out the features on your mold (concave, kick/nose tails, drops), you are ready to shape the foam to your design.

The mold can be made out of foam, mdf or other stable and shapeable materials. The denser the material, the more it will hold up over multiple pressings, but the harder it will be to shape.

Let's get started:

Set the blade of the utility knife just above the depth of the side profile line and make a series of cuts across the foam, about 1" apart.

You can see the cuts I made on the tail of the deck in this photo. Make sure you do not cut below the profile line. Using a saw cut above the profile line as shown. If you don’t have a saw, the utility knife blade will work as well, turned on it’s edge.

Remove the excess pieces of foam.

A little messy looking but don’t worry, you will be smoothing this out with the sanding block.
kawriver5 months ago
Great Job! Quick Question: How many layers of plywood and what was the thickness?
From the pictures it looks like you might have used a Polyurethane foam sheet sandwiched into the middle.
sle59 months ago
Nice'! Do you have a link on how to do step 4? Let me know please :) thanks!
Rockitalk (author)  sle59 months ago
I will add one on how to use the Thin Air Press soon hopefully! We do have videos and tutorials on YouTube -

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