Boards for eFoil


as its my day job If I can be of help in creating a cad file on shape 3d and the g code for people to cut it on there cnc for personal use I have a full licence for shape3d which is a board shaping software I’m happy to do draw up a basic design and file that people can down load.

bellow is just a example of what I normally cut


That is very nice! I have a question. How do you line up the blank when you flip it over to machine the other side?


I have a center line machined down the table and then just a line on each end of the blank.


What are the consequences of using a larger board? I have an old windsurfer I am considering using. I assume greater stability but also greater drag until airborne. Or perhaps there is less drag because of increased buoyancy? Increased weight. Anything else?


I wonder myself. Since foiling is a physical challenge on its own, I want to make it easy to learn.


probably the biggest thing is swing weigh, having a smaller lighter board means it is easier and faster to react, the odious benefits of less to have to lift. Having a bit of width will also hep a lot when you make a unscheduled landing and offer a bit of stability when taking off or going at sub foiling speeds.


Another factor in the volume consideration is if you have to paddle back to shore in the event of no power.


This is such a great place for the DIY. My project started from scratch in August with building my board.My idea was to create a hollow medium sized wooden surfboard. First goal was to float👍.

As you can see, my mast was pretty amateur and the foil the same. I’m currently reworking the mast- I will post when I have it updated.

I was pretty happy with outcome of the board- sealed it with teak oil and then marine spar urethane. I tried the board/ foil in early September as a tow behind the boat before the boat was put away for the summer. I believe the mast was my downfall - I could stand up on the board but no matter how how far back I was on the board, it would nose dive with slight increase in speed. I believe I had too much drag on the mast. I’m also improving the foil now that I’m finding more information out there to go on. I have a video on the water- just can’t upload.


@Dave, Hopeing this will help, if it does, see more videos on youtube from Delta Hydrofoil Pro Tip. :smile:

Good work tho…


So the guy in the video confirms my theory in the „lets make the optimum wing first” thread. In the first 2min he explains how the kite creates a large moment. We don’t have that moment with the motor pushing close to the wing. So we probably all should modify our back wing for less downforce.


Oh definitely helps - thanks for the response and video link.


Hi just thought i would start to post after following this site for a while. Below is a pic of a board and foil , the board is am old SUP with high density foam layed in for the mount and it’s my second wing the first failed in the fuselage, we live and learn.


today i‘ve planned an cut out a prototyp in the size of 30% from the original. the final one has a size of 160cm65cm13cm, so i think i have enough volume.


I completed the first of at least 4 lamination cycles. The bottom is far from smooth, but should be very strong. My vacuum bag ripped, so I couldn’t apply enough pressure to keep it flat. It will probably remain uneven. Hopefully the top will be smoother!


Progress on the board so far. Now ready for glassing. Going to use 2 layers 6oz glass top and bottom with an extra 6oz patch where the foil goes. Didn’t have a hot wire cutter so I had to block sand the entire bank.


Looks very nice. Sanding it by hand must have been messy. Here is what I learned from the glassing job:

  • I probably mixed 20 batches of epoxy in total. A coat hanger wire can be bend into an L-Shape to use it as a mixer in a cordless drill. Well worth it.
  • I used 35 pairs of gloves.
  • Put your scale in a plastic bag.
  • Taking your time to cover all surfaces with plastic is worth it.
  • Any air bubbles underneath the glass will become holes during sanding.
  • Bags filled with water help pressing the glass into the electronics cavity.


thanks for sharing @maxmaker. @goldy nice job!


Thanks Max. Yea it was really messy, not the best way to do it. Great, thanks for the tips, I will use the plastic bag filled with water for the electronics cavity, was thinking about what to do to press the sides in. Cheers


I vacuum the compartment by itself and then the board


Not the best way to mix epoxy with a drill (high speed) unless you use a degass chamber on the epoxy, it creates load of bubbles. Slow with a “paddle” will give lot less bubbles.

Vacuumnagging is not that hard, and will give really good results compared to hand layup, especially in corners and other complex geometries. Your fiberglass/epoxy will be lighter and “stronger”(higher tensile strength) as well, due to a better ratio of resin and cloth, the fact that almost all air is removed and the cloth sticking well to the foam below.