Yeah I like the dual box AA , that's the way to go . The fight is still on for Tuttle or track mount. I'm vote one for Tuttle but for my new prone board I'm going track just because of board thickness. The Tuttle/track convert mounts are still heavy, cumbersome & expensive. Personally, I'd like to see the mast mounts on the foils to screw off & on Tuttle or Track mount. It's early days in the VHS v Beta battle. The back of my car is like a Bunnings store but the dual box Sunovas are the way to go. Well done to Bert & Tino.

Getting plenty of enquiries on this board from all over Oz. Being a 2in1 SUP Surf Foilboard with both mounting options appears to be a pretty unique combo right now. Certainly down our way. Casso just took the 7'4 away with him on a 4 week road trip so we should see plenty more action on the board as a SUP as well as a Foil board.
Just heard there is the addition of 7' - 95L board to the range available in June
7'0 x 28" 95L
7'4x 29" 110L
7'8 x 30" 125L
8'0 x 32" 145L

Jimmy Lewis Boards said..
If you need to adjust anything then adjust your feet & body positioning... You can always get the Manta adaptor...

+1

More options around than you think

Francone said..
I'd like to experiment hydro foiling on my 11 ft Bic windSUP.
[...] I'd appreciate comments and suggestions on the above.

Don't do it !!!
It wont work on such a large and heavy board.

Foiling is quite technical. Trying to learn on ill designed gear will not be worth it.

colas said..

Francone said..
I'd like to experiment hydro foiling on my 11 ft Bic windSUP.
[...] I'd appreciate comments and suggestions on the above.

Don't do it !!!
It wont work on such a large and heavy board.

Foiling is quite technical. Trying to learn on ill designed gear will not be worth it.

Yes, It may not work, but I don't believe the weight and size of the board are an issue, because , as the attached pic shows, people foil on Konas and/or Exocet longboards boards, too , like the 2018 EXOCET WINDSUP 10' & 11'8", which are practically the same weight , length and width as my Bic WindSup. The problem might be rather the material, fiberglas-reinforced wood, which could break and perhaps some oversimplified physics.

I have already built the main wing and the stabilizer wing with fiberglas reinforced wood .( I can't afford carbon )
The main wing has a size of 85 cm x 30 cm. This is the size, which according to the Bernoulli formula, yields the power necessary to to lift board, rig and myself ( 120 kg total) at about 10 knts speed. I know the drag will somehow erode the lift force, but I figured out according to technical charts that the drag is minimal by keeping the angle of attack between 10 -12 degrees.

The most delicate and painstaking part has been shaping the wing as close as possible to a real wing. This is the most technical and crucial part. i.e. shaping the wing with the upper ( low pressure) face slightly convex at the leading edge (and tapering down towards the trailing edge ), while the down( high pressure) face is slightly convex( hollow) to maximize the pressure differential. It had to be done all by hand, with plane and sandpaper, inch by inch. The fuselage linking the the two wings is also out of wood.

If it works as well as it looks, it will be great. I hope for the best and I am prepared for the worst ( losing or breaking the foil, but it is only worth few $$ in material, resin and hardware.)

Take a look at the Kona pic , with the foil
( www.iwindsurf.com/forums/viewtopic.php?t=33132&sid=6e48e3378b7afb15cb69eaf208412021 )


I'll try it out as weather warms up a bit more. I'll post the results.

Thanks for the input

Francone

colas said..
Mmm... are you speaking of Windfoiling? This is totally different, with the power of the sail, a big board is not a problem: you just fly it totally straight, the power is in the sail.

For SUP foiling however, the power is the wave, and you need to subtly move the board to tap its energy. A big board can work, look Robert video(*) on his 14', but the range of usable conditions becomes much smaller (you will need more perfect waves), and notice how he moves his 14' in the air... a 16 kg board (after reinforcements) will be much harder. I guess it is doable if you already know how to foil, but the learning curve will be harder.

I always advocated centering the foil to have it closer to the board center of gravity in my posts, but let's just say it seems to ruffle some feathers :-)

In a nutshell, just aim to windfoil it at first, to learn as much foiling as possible before attempting without a sail.

(*)

PS: A flat bottom for the wing works, you do not need to go to the hassle of a concave bottom.

PS2: if you do not use carbon, try to make the foil as rigid as possible. Any wobble in the board/mast/wing assembly translates into insane handling problems.

Sorry, I was not clear. I always meant windfoiling. I wouldn't go SUP foiling at least for the moment because there are no waves to surf on here, just a flat lake..

For the mast I have used a 0.50 " wood plate,i.e. thick enough for good rigidity.It is only 50 cm long, though.
In order to have a better handling I didn't go full length, also because the water is rather shallow here and too long a mast would be in the way, possibly break.

I don't know if it is long enough to provide lift. To be honest, I don't even know if there is a relationship between mast length and lift force. From what I can see, there may be none. A longer mast may just allow to ride higher up on the water.

May be you can comment on this.

The crucial point is how to attach a plate to the hull without using bolts, but I think there is a solution.

The Foilmount company ( foilmount.com/products/foilmount-standard ) sells a ready-made glue-on mast plate for surfboards.
They use a special 3M double side tape which apparently is so strong that one can hang full weight on the mast and the mast doesn't come off. ( There is a demo video on their site)

I went to the 3M site and I believe that this tape is their model 4941 VHB ( double sided acrylic foam tape,) available on Amazon, too.

3M claims it is so strong that it can replace rivets, bolts and even welding.

Some warn that the glue strength can be a liability, because if the glue is too strong for the plate to come off, then the hull will bear the brunt and possibly delaminate.

Perhaps the risk of delamination can be reduced by using a plywood plate . Plywood itself is laminated and hopefully, if the glue doesn't yield , the plywood will delaminate first, instead of the hull. I may lose the wing assembly, but no big deal, just a few $$ worth of wood, resin and hardware.
I believe though that if this glue works on the Foilmount demo SUP without delamination, it is even safer on regular windsurfing boards, like my Bic WindSUP, Konas and Exocet, which are built differently and probably stronger.


Francone

colas said..
Ah OK. I never windfoiled, but I know Gong plans to make a thicker mast for windfoiling: The shaper says that masts used in SUP foiling are not rigid enough for windfoiling. So you may want to reinforce it quite a lot.

A shorter mast is a good idea to learn on: less mechanical stress, safer falls.

On the foilmount, if you read this forum and the Zone, you will see that any solution that only anchors on the hull will break in the long term. The glue is not the issue, the hull just delaminates (and one foilmount itself broke at the bolts holes)
I would just reinforce the hull with carbon layers before glueing the foilmount.

Or you can just use Piros solution: screw the foil on a plate, and duct-tape it under the board :-)

I have a board where the tuttle box pushed a bit sideways the hull which folded. I just glassed 6 layers of 12oz carbon on a 1' area over the hull around the box, it is now super solid, it makes a small buldge on the hull but nothing dramatic.

Duct tape? Never thought about it! It is an interestiing solution , certainly a cheap one, well worth trying, but I am a bit perplexed: how can duct tape hold, if, going by what most "experts" say, the hydrodynamic forces on the foil are so strong that carbon must be used?
Along this line, then, one may also use the double-sided carpet tape, perhaps in conjunction with duct tape. I'll try it on a sample at home.

By the way, I searched this Forum, at least the thread "SUP Foiling, my first steps" but none of Piros' s numerous and extremely well informed posts mentions this solution. I couldn't find any post ( Piros?) suggesting this solution. Perhaps I should PM Piros.

Regarding the foilmount delamination issue, I contacted Foilmount. They say that pretty big names in the industry such as John John Florence, Kai Lenny, Damien LeRoy, Chuck Patterson, and many others use their mounts with great success, assumedly without any delamination problem. They acknowledge it, though, but this is what they say in their last e-mail( Phillip Midler) :

Quote
Franco,I looked up that board's construction ( i.e the Bic WindSup) and it should be just fine.Generally speaking windsurf boards are great. The outside of the board is Acrylic-Styrene-acrylonitrile, which is not listed by 3M but is very similar to ABS plastic which our acrylic adhesive tape sticks to wonderfully... The construction is also important as laminate boards like bamboo and others that are Chinese made are not good it is best to have a foam core with poly or epoxy resin bonded directly to the foam. On laminate boards they will use a very cheap EPX foam that is hidden behind the opaque laminate.no good for anything other than paddling around the lake. Long story short I don't think you will have any issues.
Unquote

Regarding your suggestion of glassing layers of carbon on the hull where the plate will be glued, I believe the idea is to strengthen the surface so that the carbon will bear the brunt of the stress, without peeling off or delaminating the hull. I
It might be a good idea, because material always breaks at the weakest point. Even if plywood is used, if one of the the two joined surfaces ( the hull) won't yield, the other weaker face (plywood ) may well come off, because the plies are glued to one another.
If the plywood face yields, this may be a good safe valve, preventing the hull from being damaged by delamination, but in the end I may have the collateral damage of losing the foil!!. I'll see if I can get some other homogeneous material for the plate , like ABS or other) instead of plywood and then using the carbon layers you suggested.

Thanks for the hints.

Francone

colas said..
Duck tape... Here it is!

For delamination, I think small surf foil boards exert less effort than big SUP boards, but since you are doing it on a lake, you should be OK. The main danger is having the gear tumbling in whitewater.

For the carbon layers, yes, using smaller and smaller patches on tp of each other you avoid making a hard point on the hull. Plus carbon sands aways easily if you wantto get rid of it.

I'll use duct tape wrapped around the hull for added safety measure, but only on the front and rear sides of the mount. No need to attach an additional shaft on the deck length-wise and tape both in the back and the front., because my mast is relatively short.

Incidentally, I have made a test with double face carpet tape ( yes, carpet tape!) on an ABS smooth surface ( garbage bin!). So strong that I couldn't pull it out by using 80% of my strength!!
I'm confident it won't come off when foiling because I believe the forces on the foil assembly are not nearly as strong, at least at slow speed and in calm waters, as using muscle.
Also, when foiling the forces on the fuselage don't pull the mast down, but more sideways.

Somebody has also suggested to to tie the assembly to the board with a twine, so that I wont lose the assembly if the plate comes off.

I'll post the result as soon as the weather permits, probably in June .

Thanks for your help

Francone

Further to my previous posts, I have now completed the windfoil prototype for my Bic WindSup, which I'll test as soon as weather permits.

Unlike most conventional boards, though, my foil cannot be mounted at the very end of the board, because I can't use the fin box..

To insert the 60 cm plywood mast, I had to build instead an 18" wood rail between the end of the fin box and the center board slot.
I have 18" to play with and can always try various settings at the beach, but in the meantime I wonder if anybody has suggestions on the the optimal position of the foil, given the length of the board: towards the back or the front? What would be the difference in handling?

Also, I read that the rear stabilizer wing can increase the lift in light winds, by tilting it downward. I didn't know it, so, as it is now, I cannot adjust it, but I can always modify the fuselage to allow adjustment of the rear wing angle .

By the way, I followed Colas advice to use duct tape. It is fine, but for added strength I have also glued the railing to the hull with double face 3M carpet tape. It feels very strong. It doesn't come off even by twisting, pushing and pulling the mast with reasonable force . To top it all, I have also fastened the mounting plate to the hull with straps. It should be O.K. in the water , at least in light winds conditions. Any comments/suggestions?

Thanks

Francone

Two points:

1.The duct tape suggestion sounds good, but it is perhaps a bit unsightly. Maybe regular carpet tape is just as good (and less obtrusive ) to hold the plate in place. I tried it and the plate it is hard to pull off by hand, at least with moderate strength.

For more secure fastening, I can always use a few retaining brackets glued to the hull with a U.S. made super-glue : J-B Marine Weld epoxy.
The manufacturer claims it has a 3900 lbs/psi strength A lot!

In fact, I joined two small ( .50") metal angle brackets back to back with this glue and tried to pull them apart by hand with all my strength , clamped in a vise. . The metal starts bending, but the glue holds! I am positive they won't come off when sailing.

The downside may be that the glue is so strong that the hull will crack or delaminate first, unless, as somebody suggested in this Forum, I reinforce the hull with a layer of carbon at the precise spots where the brackets are to be glued. Perhaps a couple of narrow carbon strips will do.

2. Stabilizer rear wing: I have angled the main wing at 10-12 ?( the L.E. is pointing slightly up for better lift).
Is it better that the rear wing , too, has a L.E. tilted upward, like the main wing, or does it have to be tilted the opposite way, i.e. slightly downward, perhaps for better stability? . Or does it matter at all? Can it be left on a horizontal ( neuter)plane?

Thanks

Francone