Any interest in a build thread?

[Surfdad]

Measure the center point, mark it and then adjust the blank, upside down, until it's level on that mark.

[Surfdad]

My rocker stick is a piece of aluminum angle. I've previously measured and marked at the center, but I like to be certain it's all level before measuring.

[Surfdad]

Then measure the gap between the rocker stick and the blank. Here I'm measuring the tail rocker. This blank, before any shaping, has a tail rocker meaurement around 1 and 1/8"

[Surfdad]

So those measurements are helpful in establishing a baseline. If you have a favorite board, you can now grab the rocker measurements off of it and transfer it to your blank. Also, over time you'll develop a taste for rockers. Currently no one really swaps out boards when they change wakes. A super steep wake should really dictate a more rockered board, or things like just cruising would dictate a less rockered board. Also, you'll see rocker measurements on blanks and you'll be able to tell if you can hack out your wakesurf board from one of the blanks you're considering.

[Surfdad]

Now let's talk about an alternative. Most surfboards have a continuous rocker, so we know that we can always establish a tangent off the curve and copy that to a similar curve. BUT that isn;t always true with wakesurf boards. We've probably all ridden an Inland Surfer Blue Lake and those boards don't have a continuous rocker. Also, skimmers often don't have a tail rocker. Measuring off the center point can give odd measurements. BUT an alternative is to measure off the apex. Virtually all wakesurf boards have a apex in the rocker and while it won't give you a comparable measurement for ocean surfboards it can make developing rockers from other wakesurf boards much easier. Something to tuck into the back your head as you're thinking about rocker lines.

[Surfdad]

Ok, the next part of the shaping requires that we introduce a rather controversial concept. That is that our wakes or really any wave formation does not have "push" in the sense that wake is actually moveing towards the boat or the shore.

The actual movement of the water in the wave formation is up and down, in a circular motion.

The best example is when folks at a large sporting event make a wave, each in turn, standing and then sitting. That's the conceptualization of how water acts in making wakes or actually waves in the ocean.

When we wakesurf, our boards capture that upward flow up the wake and redirect it out the back of the board. Wakesurf boards that do this more efficently can normally carry a larger rider. One of the observations we all have had that can help folks grasp that concept is a LARGER board tends to help folks ride weaker wakes. That larger board is creating more wetted surface area and thereby grabbing more of the flow fromthe wake.

A good reference about this concept, where waves don't actually move towards shore and doesn't move matter, can be found:

http://myplace.frontier.com/~gpresby75/id1.html

No the "breaking" part of the wake/wave is different, but we typically don't surf the mush ball.

So what I'd like to impart for today is that the bottom shape of your board will be critical in it's performance. You'll want to consider how to best capture the flow of water and move it out the back of your wakesurfer.

[Guma]

^^^ WOW, this is an amazing explanation of what is going on back there.

[Surfdad]

Thanks Guma, that concept normally catches folks by surprize, but we'll need to think about waterflow as we create our shapes.

Ok so back to the shaping. This blank is a little limiting for the designated purpose, so I want to give it some help with capturing the waterflow up the wake. Normally you might want to keep the bottom flat on a cruiser, but since we will be "outline challenged" on this board and I know that Sheldon has good riding skills, I am going to put a generous concave in the bottom of this board. This will do a few things. One is effectively flatten out the rocker. You saw in the previous posts that the tail rocker measured up an inch or so. I'd like to reduce that somewhat, without reshaping the entire bottom, so by shaping in a concave, I will reduce the "height" of the blank forward at the mid point and thereby reduce the overall tail rocker.

Also, thinking about how water flows UP the wake and it doesn't PUSH from behind, the concave will be an aid in capturing that water flow and channeling it out the back. Providing some lift increase also.

So, with the design in mind I will roughly mark out the outline of the area I want to scoop out for the concave. I just use a number 2 pencil to roughly mark the shape. If you decided on a more intricate bottom shape, such as say channels, you'd want to measure, mark and double check before making the first cut.

If anyone has questions on bottom contours we can take some time to address the theoretical concept behind them.

So marked entry of the concave.

[Surfdad]

As I discussed earlier, the concave will have it's deep point down the middle, so I will start the first cut down the middle and then work each successive cut radiating outward, in that way the middle will have the deepest cut and working outward towards the rails, it will get less deep.

In the first picture you can see the fresh white cut and in the second picture, there are now three paths, the center which has two passes with the planer and then two on either side of the center cut.

[Surfdad]

This next picture gives you a visual of the shape of the rough cut concave and the stairstep idea that I talked about earlier. The electric planer allows us to mow a BUNCH of foam quickly, but it is rather imprecise. We'll use hand tools to do all the final bits of shaping and smoothing.

The level also makes a great tool for measuring depth like this. We'll place it across the bottom and then measure the depth from the bottom of the level to the board. We can't get 100% accurate or matched, but if we can get within 1/32" on each side, to the design we'll be golden and probably never feel any deviation beyond that.

[Fiveflat]

This is getting awesome!

[TigeTrojan]

I was doing some fiberglass repairs on my boat last week and I was told that the board builders are the best fiberglass guys out there. I'm excited that we are getting close to that point here. Are you going to be putting graphics on this board? I assume so, but just in case, can you add a quick explanation when and how the color and/or graphics go down?
Thanks.

[IDBoating]

Since people stick with their native "normal" or "goofy" most of the time (rather than switch), I wonder if anyone has experimented with an asymmetrical board optimized for their preferred side. Seems like since the wave under you is asymmetrical, there would be ways of optimizing for that. If you always knew the wave would be toward the right edge of the board (normal), for example, you might offset the fin(s) toward that side.

[Surfdad]

Thanks for following along guys.

@ TigeTrojan. I will be doing some graphic elements. I've been trying to figure out how to do several different things, just so folks have an idea of what can be done, but not make it look hideous. I may wind up doing a geometric on the foam itself (demonstrating that) and then a resin swirl OVER it partially to demonstrate that. I'm sure it will come out looking like something only a mother could love!

@ WAboating, Carl Ekstrom is generally regarded as the godfather of asymmterical surfboard shapes. I got to see one of his designs in hydroflex at sacred craft a couple of years back. It's definately interesting! They look weird and that is probably why they aren't around much, but conceptually it makes sense that you'd have different shapes to optimize your frontside and backside riding. I've never been able to fully grasp what I would change to optimize the two different sides. I mean I never feel like OH! I wish my backside fin was 2 inches forward. I tried one several years ago, but I really had no idea what I was trying to achieve, so it rode like crap If someone really had a grasp of what differences they wanted front and back, that would be the ticket.

[IDBoating]

I've never been able to fully grasp what I would change to optimize the two different sides.

Me either, but giving it some thought I can imagine having my "wave side" edge be sharper for better edging in the wave face, while my "non-wave side" edge might be softer to be less likely to catch or pearl unintentionally. Those two edges definitely see different water - one is basically horizontal while the other is varying degrees off horizontal - so I would guess different edges would be optimal for the different conditions.

Just some rambling thoughts.