Hacking a CHEAP INFLATABLE SUP into a Wing Sup! sUp Wind DIY Daggerboard and Tail Edge Release.

[@stratos2]

Neat creation! I would be interested to see a performance comparison of the board with and without the rear step on it, measuring the drag. This may be quite a neat addition for normal paddle-driven SUPs too.

[@LostWax2]

Yeah, I'd be interested in that too. My gut feeling is that you wouldn't notice a difference when paddling the board, as you are going quite slow anyways, but as you get faster, the drag effect becomes more noticeable. But, yes it'd be cool to see an actual experiment!

[@kevinknelsen221]

Hearing your voices made me miss you guys today...love the videos!

[@LostWax2]

Awww, good to hear from you!!

[@rolandblais]

Looks like so much fun!

[@tundeszabo7595]

enjoyed watching, awesome video

[@ruthbryant3929]

Enjoyed watching you have fun!

[@LostWax2]

Glad you enjoyed it!

[@pantone95330]

Nice tutorial, thanks. For those who don't have the tools or the knowledge to do this, you can buy a SUP convertible for windsup, meaning it already has a center fin plug. I did it, it works, the rest is about spending time in the water to master it, it took me many sessions just to be able to go back from where I started.

[@LostWax2]

Definitely!!

[@renaudp5390]

Awesome 😊

[@LostWax2]

Thank you! Cheers!

[@Z0MB13Redfield]

This makes me miss living closer to water

[@PavelBarbanegra]

Very very cool! A semi-rigid hard chine edge, like on a performance Inflatable power boat, or a Starboard inflatable windsurfer/windsup! A question, if I may: the daggerboard is in front of the planing surface you have created. Although it undoubtedly works, as evidenced by you being able to go upwind with it, a daggerboard or a pivoting centerboard is usually a feature of a "trainer"/beginner windsurfer boards. I mean, all performance windsurfer boards tend to only have a big (like, really long and sleek) fin at the back, so as to do away with any forward-placed obstacles that might get in the way of getting tge board on the plane. And when planing, only the very short back section of the board would be in the water, so the daggerboard in the front would then become a source of drag, throwing you off the plane. Also, for upwind performance, a long, short chord fin/daggerboard will always outperform a short, wide chord one allowing for higher upwind angles. So, in your opinion, would it be feasible to print a finbox that would take a TuttleBox performance windsurfer fin? Or print a prototype finbox, take a mould off'f it, and cast a usable one out of 2-part polyurethane? And mount it in the back, in place of the original sup fin (that is nowhere near the needed surface area)to allow for better upwind performance and easier planing? That would also make it possible to use a plethora of readily avaliable performance windsurfer fins.

[@LostWax2]

This is a fantastic comment, and includes a lot of things I have been thinking about as well. First off it would be amazing if I could get this board up on a plane with a wing, but I wonder if that is really an accessible idea- for one, it is a big board, so there would be a lot of surface area drag, and second, I feel like wings aren't the most efficient sails out there. Lastly, as you mentioned there is the drag from fins and fin boxes. There's two main issues I see with inflatables, and that is 1: you need to mount the fin box on the exterior of the board, inducing drag from the box, and 2: because you are mounting the box to an inflated surface, it is a bit flexible, so your fin will have a certain amount of tilt either way, depending on the pressure. Some board companies fix this by having an insert for the fin box that goes through the board, but that's beyond my board hacking ability:) The reason I went with a shorter wider daggerboard is that I wanted to reduce the sideways push on the fin box by spreading it over a longer length. This does sacrifice the some speed that a longer, thinner daggerboard would achieve. After this experiment, I decided I would like to try convert a cheap sup into a windsurf board, so I have bought a 8ft kids board that is almost the same dimensions as the starboard airplane. I want to make a removable centre daggerboard fin box so it can be there for learning and remove it to try get the board planing. The problem I haven't solved yet though is how to get enough fin area at the tail without too much drag or pressure on the box itself.......Maybe twin fins? That'd spread it out, but add drag. Anyways, that was a bit of a ramble, but just kinda thinking out loud:)

[@PavelBarbanegra]

Nice ideas! Also, I guess a wooden/plywood "ducktail" with a fin box inside it, can be made. Decathlon has an inflatable sailing dinghy, Tribord 5s (basically 2 SUP boards glued together, with a slot for a daggerbox), that has a plastic, nicely shaped rudder plate that attaches to the transom of the board. So if we glue a piece of keder to the bottom and to the top of the transom of the SUP board - to act as live hinges for attaching the "ducktail" to the SUP while it (SUP) is not inflated, we can utilise the internal pressure of the SUP as the clamping force needed to secure the "ducktail" firmly in place. The fin will go into the "ducktail", and all finboxes can be removed from the SUP altogether, reducing drag and flattening the bottom nicely to promote planing. The chines will only need to be on the sides, 'cause the bottom keder, pulled tight between "ducktail" and SUP bottom, will provide a smooth, flat transition from one to the other. Will try to cobble up s basic proof-of-concept 3d model and provide a link later today

[@PavelBarbanegra]

Also, Starboard has a couple of "touring" inflatable windsurfs with volu​mes of up to 230 liters, I beleive, and those can and will plane (there obviously is a learning curve to that). @@LostWax2

[@PavelBarbanegra]

A side note. I've been thinking that it might actually be possible to "freehand form" the chines 'in situ' out of 2-part pvc/silicone caulk, almost like "open mould casting" them. Or sculpt them in place out of car maker's prototyping clay, take a negative mould, clear the clay off the SUP, fill the mould up with thick caulk, butter the SUP up with more caulk, slap the mould back onto the SUP, wait to dry, demould. Would be finicky, no doubt, but still doable. The commercially avaliable glue-on chines for inflatables are pvc or silicone rubber compound (but quite a bit bigger/thicker than needed for our cause - otherwise I would have already glued a strip of that to my cheap SUP).

[@LostWax]

@@PavelBarbanegra Interesting, though I can't quite visualize the concept you are going for here. I get the idea of adding an extra bit of tail so to speak, but I don't understand your attachment idea. Another thought I had was use twin fins at the back, but kind of like your above idea, instead of attaching them individually, have the fin boxes part of a large flat sheet glued to the bottom of the board- so any lateral forces would have a strong base acting against them, and the two fins would, in a sense work to stabilize each other, as the inside edge of one fin box would be pressing down while the inside edge of the other fin box is pulling up when lateral forces are applied. I notice STX makes a board with twin fin boxes that are pretty much what I made for the board in this video.

[@JonMadsen70]

:)