DIY Kork Tail Pad

When I finished my first wooden surfboard and started looking for a tail pad, I quickly found that the colorful EVA versions did not match my wooden board. At this point there were no commercial cork tailpads, so I started testing materials for a custom one.

I tried to imitate the sole of Birkenstock shoes (latex vulcanization with cork) but in the end I didn't find a promising option, at least none that consists only of natural materials.

During this material research, I built some prototypes and one of them is still on my wooden board. I like them so much that i put one to every new build. The tail pad is light, has a lot of grip, and feels great. That's why I want to show you how I made this.

silicone, wood for the frame, plaster, Mold release agent, Bostik Spritzkork 3070,

The first version of the positve mold was CNC milled, here I will use a 3d printed one. An existing tailpad can also be used.

Here you can find my 3d model:

https://www.thingiverse.com/thing:4943559

The mold should be treated thoroughly with a mold release agent, as silicone adheres very well.

Silicone from the hardware store can be diluted with various paint thinners, please test beforehand.

Nitro thinner and acetone worked best for me. I took about 2 parts of silicone and 1 part of thinner.

The Silicone thickness should be less than 10mm.

A Silikon and soap combination or 2k cast silicone can also be used.

To reinforce the silicone mold, fill the rest with plaster.

The silicone mold should be prepared with a release agent as well. Because the typical ones would stick to the cork in the end I recommend using oil. If somebody finds a better solution, let me know.
Now it's time for the magical cork component "Bostik Spritzkork 3070". I tried other variants and other brands, but they didn't work. So I hope Bostik is available outside of Germany.

To spread the cork in the mold some plastic foil helps, it can be pulled off in a steep angle afterwards.

To spred the cork evenly the printed Mold is used (see picture 3). Some clamping is recommended.

Leave the cork to cure overnight and then carefully unmold it and let the other side cure. The surface cures faster so there might be some deformations during the process but don't worry it will flatten out again.

I used PU glue to get it on to my boards.

That's pretty much it.