Foils obviously play a crucial role in the design of a fin and can dramatically impact the performance. Most of our foils are loosely based around the NACA 00 series of wing sections that are ideal for fins.
We pay careful attention to the foils used on all our fins. We try to match the best foil for the characteristics of the fin and wherever possible we try to keep the regular foils nice and thick for maximum efficiency.
HANALEI FINS are unique in that we have perfected the use of inner hollow foils on the inside faces of most of our fins. We use these foils to increase performance and efficiency. In many cases we also couple these foils with twists and turns in the trailing edge of the fin to better manage the ejection of water from the foils. These foils have a dramatic impact on the overall performance of our fins, but in particular to the speed!
There are a lot of different fins systems available in the market, many with their own unique style of base. HANALEI FINS only supports the three primary bases - GEARBOX (our base is also compatible with ProBox), DUAL TAB, and FUTURES.
The GEARBOX base is used in our own fin system GEARBOX, it features a full base for a solid feel and greater strength. The GEARBOX base also features vee notches where the screws land that allow the fin base to be forced down into the box when tightened, creating a compression fit.
The GEARBOX base is also compatible with the ProBox Fin System.
The DUAL TAB base is widely available due to the large number of boards with the twin plugs installed. The DUAL TAB base also fits in the GEARBOX fin box. These bases are designed to break under load and therefore tend not to be very durable, breaking at inopportune times. the other problem with these bases is the tendency to flex in the base instead of the fin, this is due to the narrow interface between the fin base and the box.
The FUTURES fin base is a lot longer than other bases due to the design of their box. Due to the nature of the fin ox design the cant angle is built into the base of the fins instead of into the box. This makes it really complicated making fins for this system, especially if they are custom fins as the can angle has to bee machined into the base of the fin. Fit is critical for these bases as there is no means to tighten them if they are loose.
These bases can also be a lot heaver due to the fact that they are almost double the length of a GEARBOX or DUAL TAB base. This is why you will commonly see these bases heavily machined in order to lighten them up.
RTM molding is one of the most predominant methods for molding fins. It stands for Resin Transfer Molding. The fabrics and core that make up the fin are laid dry into a mold. The mold is then closed and a vacuum is used to draw resin through the mold, wetting out the materials in the process. The use of a vacuum also draws all the air out of the laminate eliminating air bubbles.
RTM molding is a lot more cost effective and less wasteful than the standard method of foiling a fin out of a solid panel of fiberglass. Because a mold is used it also makes it easier to manufacture more complex shapes in a consistent manner.
Fins can be made out of a wide range of materials, but these are some common standard materials, with fiberglass being the most prominent one. RTM molded composite fins use a combination of these materials.
Fiberglass forms the bulk of a fin construction and is applied either side of the core material in our HRD-KORE construction method. The typical fin can have as many as 27 layers of fiberglass to provide strength and some flex.
Custom fins are made out of panels that are built into solid sheets of fiberglass and resin. The number of layers can vary from 30 to 40 layers. This is the standard material for hand foiled fins.
Carbon fiber is very strong and stiff for its weight making it perfect for base stiffening. Employed in the base area of the fin to add stiffness and strength, it is applied to both sides of the fin as an outside layer that is visible in the finished product.
Soric® is a conformable flow media for resin infusion. This product features unique hexagonal flow channels across a carrier sheet that create a steady, even resin front. Forms the core for the fin and reduces weight by reducing the layers of fiberglass needed to construct the fin.
G-10 glass cloth reinforced epoxy natural is typically a yellowish to light green color. The most versatile all-around laminate grades are continuous glass woven fabric impregnated with an epoxy resin binder. These panels are made under high pressure so there is no air in the panel and the resin to fiber ration is very high. This makes for an incredibly strong panel.
Because these panels are manufactured it makes it a lot simpler for a fin manufacturer as one simply purchases the panels and then cuts fins out of it as needed. The panels are a lot more expensive than a standard fiberglass panel, but worth it for the strength.