In the last post we talked about all of the wakesurfs that are currently doing additional rail reinforcement or stiffening and we forgot one of the major players, Airbaze. Now they have Burt Burger manfucaturing for them out of Thailand, under the Sunnova label. Burt Burger and Josh Dowling pioneered the parabolic stringer arrangement, where the rail material acts as the stringer using wood built up on the rails. They have both been doing this for years now. For students of the Flyboy you’ll remember that the Gen 2 Flyboy Wakesurfs used built up rails with basswood and balsa, it was defintely a way to stiffen up the rail line.
If we think about that, the vast majority of surf style wakesurfs that are being manufactured, or have been and that are successful in the podium chases, have been using some form of rail stiffening in the design, even if that wasn’t one of the specifical attributes sought, the net effect has been there. We have a great deal of respect for folks that are in the shaping business for wakesurfers, even if we prefer our own shape and promote the benefits of those designs, it doesn’t mean we think less of those folks skill set. That said, we would have to think that each of those shapers/designers are cognizant of the rail twist-off issue and are tackling it in their own way. It could be that one design comes out as the best in the end, but there really is more than one way to skin-a-cat and each of those wake surf board manufacturers that we mentioned are implementing their own design.
That by itself feels amazing to us here. Let’s count them carbon fiber, parabloic rails, inset perimeter stringers, concave deck, step deck curves. So that’s five unique variations on a theme! That’s probably the most variety in contest level boards of any attribute!
Now we’ll expose one of the design elements that we use on the Flyboy Wakesurf boards that we’ve not really mentioned before, but it feels like high time!
You may remember back in the beginning several years ago, the Flyboy Wakesurf boards all had a perimeter frame of high density closed cell foam. It offered a few things, one was perimeter weighting as the high density foam is about 5 times the weight of the core. It’s also closed cell, unlike balsa wood, or EPS, and so if there is a ding you won;t take on any water. In fact if you’ve followed us you saw us wakesurfing the unlaminated core with just the external skin. Tht is a testament not only to the stiffness and ruggedness of the core of a Flyboy, but also to the fact that it’s water tight!
Well all of the Flyboy Wakesurf boards have had that perimeter framework, but in the past we’ve used a single piece of 1/2″ H-80 divinycell or the built up rails using balsa and basswood. For the wood veneer boards that you’ve seen James riding in 2011 and 2012, the rail is built up divinycell. That is there are layers of 1/4″ divinycell glued up and together to form the rail before shaping. This is similar to the single piece of 1/2″ divinycell but not quite. First is that we are making the rail material a tad wider, out to 3/4″ rather than 1/2″. The jury is still out on that change, but what we want to convey is that bending the divinycell around the curves of the board is pretty hard at 1/2″ and almost impossible at 3/4″ without damaging the divinycell or the interior foam. Thermoforming would make that possible, but we’ll avoid that for the time being.
The other benefit that the three pieces of rail material bring over a single piece is a glue line. This has proven to be very interesting for us in our experimentation. The glue up creates a much stronger and stiffer rail that a single piece of material. In composites, this is a comon practice, that is layering a bunch of materials rather than a single sheet to develop the added stiffness and no doubt you’ve experienced it with plywood. Cheaper, easier and actually a stiffer and stronger arrangement. This is very similar to the way that Burt Burger is building up the rail material on the Airbaze Next composite sandwich wakesurf board.
What that requires, when we go to build this wake surf board is that we trim the core down to reflect this narrower profile. That didn’t sound clear did it? Lets try that again. We want the final board to have the same outline as all of the other boards. However, the first 3/4″ of that outline will be this new layered divinycell, so we have to measure INWARD from the outline 3/4″ and cut the core to that new dimension. We hope that was clearer!
Here is a picture to show the process, we use our template to mark inside the outline by 3/4″.
After the core is marked we use the jigsaw to cut the excess and then finally sanding blocks and a surfform to true up the vertical side of the core where we will attach the rail material.
So that’s the process we go through to prepare the core of the wakesurfs for the later addition of the rail material. Now by changing to this layering method that also allows us to swap in various components. If we find that we want it a little stiffer we could swap one layer of the divinycell with say basswood, or possibly intermix a layer of carbon fiber between each layer of divinycell. The potential here for various combinations is pretty significant.
Thanks so much for following along, we really appreciate it. The next week or so is going to be a little busy as we are preparing for the NWWSA wakesurf contest next weekend and James Walker will be up that way early to do a little instructional, thanks to the kind folks at NWWSA. We hope to see you back here soon and appreciate your patience as we get ready for that event!