Homemade fins
Making fins is easier than making surfboards.
It is also a fun process if you work at a leisurely pace.
There are two main methods.
- wooden
- FRP laminate
Both have their advantages and disadvantages, and there is also the option of buying commercial fins.
How to install fins on a surfboard
If you make your own fins, glassing them on is less expensive because you don’t have to buy a fin box.
If you are installing commercial fins, you will need a fin box that is compatible with each manufacturer, and you will also need special tools.
Depending on the number of fins to be installed, this can cost as much as the purchase of the blanks themselves.
Wooden fins
Balsa, plywood, natural wood, or whatever you like, it is convenient to make a template based on the outline of a fin you like so that you can use it in different ways.
As for easy-to-make foils, center fins and single fins are two-sided foils. Side fins, twin fins, and quad fins are single-sided foils (straight foils on the inside).
Side fins have a single-sided foil, so it is best to shape the two pieces together to get an even foil.
FRP laminate
The process begins with the formation of the laminate from which the fins are cut, which is time-consuming, costly, and labor-intensive.
Glass cloth is easier to glass the laminate, but it takes more sheets to make the required thickness.
Glass mats are thicker and require less glassing, but they are difficult to process during glassing and are prone to air bubbles.
Once the desired thickness is obtained for both, rough shaping can be made less labor intensive by using power tools.
Lamination and shaping of fins
Laminating the cut-out wooden fins based on the thickness of the finished product.
Any slight thickness differences can be corrected later in the process, so do not be too nervous about it.
The laminate will be sanded several times, but it can be shaped and hot coated each time, or it can be finished at the end of the process, whichever is your preference.
Either way, it will need time to cure before it can be sanded, so it is more efficient and less tiring to do it in parallel with the production of the surfboard itself.
Using a cookie sheet is convenient because the resin will not stick to other components.
If you use a commercially available fin box, you can make a special jig to keep the fins standing.
Setting up fins
There are many videos on the Internet for installing commercial fin boxes, so please refer to them.
For glass-on, there are roving cloths on the market that are made by unraveling glass cloth into a rope. Unraveling it does not cost much.
The angle and tilt for installation should be based on a surfboard of similar shape.
The values can be databased and will be an asset later on.
The actual setup should be done before hot coating the bottom of the surfboard.
This is because the fins and the surfboard can be hot coated at the same time.
Don’t make fins, drink beer with the extra money!
After the setup is done, it is time for the finish sanding process with the board itself.
At this point, completion is just around the corner, so let’s sand the board to our desired finish.
To be honest, if you consider the hassle as a cost, it’s faster to buy one.
Don’t make fins, drink beer with the extra money!
I saw an article on the web where a famous shaper commented on this, but I couldn’t find the link, so I’ll leave it out.
Either way, the beer you drink when the fins are done is delicious.