Building a surfboard: how to insert the fins plug

Once your surfboard is glassed, it´s time to insert the fins and leash plugs.

1. Fins Plug

The position of the fins is essential if you want that make turns with your surfboard, and I guess that you want…. There is no standard, it all depend on the kind of the surfboard you are building, and what you want to do with this board. You can copy a similar board from a major brand, to avoid making mistakes.

The central rear fin is placed at 90 degrees respect to the surfboard. However the side fins are placed with an angle between 3 and 7 degrees respect to the surfboard:

To get this angle, you can make a cardboard template, that you will use to support the fins when inserting the plug.

Fins are not parallel to the longitudinal axis of the surfboard, but they are looking toward the nose. If you extend the base of the fins, both line should cross on the nose area.

The more angle you put, the tighter your surfboard will turn, ideal for small waves, and the less angle you put, the longer will be your bottom turns, which is perfect for fast and medium/big waves.

After marking the position of the plug on your surfboard, open two holes with a spin and a crown of a diameter slightly larger than the diameter of your plugs. Open the outer diameter with a small screwdriver so that the polyester resin will grip on the other side of your surfboard.

Fill the hole with a mixture of polyester resin with glass microsphere, and introduce the two plugs screwed to the fin, and use your cardboard template to regulate the angle of the fin.

Once the resin have hardened, remove the fins, the plug´s screw, and sand the part of the plug protruding from the surfboard.

Take care to put the plug on the right way! For side’s plugs, screw on the inside, for rear plugs, one plug with the screw on one side, the other one with the screw on the other side.

2. Leash Plug

It´s pretty much the same process. We will place the leash plug at 5cm from the tail, to avoid damage caused by the leash, and in the middle of the stringer.

Make a hole, fill it with a mixture of resin polyester and glass spheres, insert the plug, and sand once the resin is cured.

Since it´s a very important part of the building process of a surfboard, we have make for you a video to show you the whole process step by step. Hit “like” on YouTube, and share this tutorial on social networks, you have the buttons below to share on Facebook twitter and google +. We will really appreciate it, it would be of great help!