What are Surfboard Fins Made of?
Here’s a quick list of some of the common materials surfboard fins are made of:
- Fiberglass/plastic/resin composites.
- Fiberglass panels.
- Resin composite over a core material.
How are Surfboard Fins Made?
Some of the main methods for making fins include:
- RTM – Resin Transfer Molding
- CNC Cut
- Hand foiling
What a surfboard fin is made out of has a huge influence over how it will flex, twist, and recoil – properties that are important when you begin to think about how your board will respond in turns and how much speed you’ll be able to generate.
Materials used in surfboard fins will also have a big difference on the weight of each fin.
Opinions on weight vary, but when you begin to think of where all the added weight it on your surfboard (it’s all near the tail in the form of your fin boxes, your fins, your leash, your traction pad, your back foot), slight weight savings could have a noticeable effect on your surfing depending on your board and the type of surfing you’re doing.
Here are some of the materials you’ll find in your surfboards fins.
Composite & Plastic Surfboard Fins
Composite and plastic surfboard fins are probably the most common fins you’ll see. These are the cheaply produced fins that most new boards will come with, and these are the types of fins you’ll find on novelty foamies.
Composite/plastic fins are typically pretty light-weight, but do not offer much in terms of performance.
With poor flex properties, composite fins are not going to make a difference in your surfing.
Unfortunately, many surfers don’t think to swap these out for fins made out of a better material.
Fiberglass, G10, and Carbon Fiber Fins
Fiberglass, G10, and carbon fiber fins are some more common materials that offer a variety of flex properties depending on the exact blend of materials chosen and the weaves/orientation of each one.
Fiberglass fins are stiff and over good recoil and flex, but come with some added weight, which is why you’ll often see notches or grooves cut out of the base of fiberglass fins.
You’ll certainly notice a performance difference with a fiberglass fin if you’ve only been surfing plastic or composite fins.
Performance Core Fins
You’ll also find a variety of performance core fins from many of the major manufacturers.
These fins feature different types of core materials and construction patterns aimed to save weight while retaining stiffness and flex recoil.
Properties of these fins vary depending on the exact materials and design patterns used.
Recycled Surfboard Fins
Recycled surfboard fins are becoming more common too. Construction varies from recycled plastic, old fishing nets, and even old skateboard decks.
Performance of a recycled fin will vary depending on the materials used, but are certainly a worthy addition to any fin collection.
Marine-Plywood Surfboard Fins
Marine-grade plywood fins are a favorite of home-builders and custom shapers. You’ll often find fins like this glassed onto custom boards.
Plywood fins have a distinctive look as the fin’s foil follows the layers of the plywood. Fins are then typically finished with a layer or two of fiberglass.
Plywood fins are lightweight and buoyant, which means you’ll experience some weight-savings and you’ll be able to find your fin floating it if snaps off.
Bamboo is a material that is extremely lightweight, strong, flexible, responsive, and sustainable.
In our opinion, bamboo surfboard fins offer some of the best qualities in terms of performance, style, and environmentally-friendliness.
Bamboo fins are made out of strips of bamboo that have been laminated together in a way that promotes twist rather than side-to-side bending.
This makes for a fin that’s fast to recoil, responsive, and speed generating.
Surfboard Fin Production Methods
Along with all the materials that fins are made out of, here are some of the ways that fins are built.
- Hand-Laid & Foiled
- The classic method of fin construction is by hand. Shapers cut out the template from the fin material and foil the fin in a few passes with a sanding tool.
- CNC Cut
- CNC cut fins offer precision, accuracy, and consistency. 3D models of the fin are sent to the CNC machines which using a router to cut out the shape and the foil.
- Another form of CNC, 3D-Printers use a filament to create the entire fin from the ground up based on a 3D-model that was loaded into a computer.
- Resin Transfer Molding (RTM)
- Resin Transfer Molding involves injecting a blend of materials (typically resin, fiberglass, and plastic) into a precision mold in the shape of the fin.