New build

[da.bell]

Okay, here is a quesiton and my understanding of stress when it comes to performance. Not sayin much but here it is.

Wouldn't the board respond better in your situation? Like a rubber band. All the force when you shoot it comes from the stress around the finger if you fire it from the finger. I know that the board is not as flexible as a rubber band but I would think that the stress on the point of contact on the "foreign" matter would be beneficial. Does this make sense?

[Surfdad]

The theory behind surfboards deals with the tensile strength of fiberglass. Fiberglass is twice as strong in tension as it is in compression. The DECK of a surfbaord, with the rider's weight pushing down on it, is in compression, while the bottom, which much flex and accordingly stretch with that increase arc, is in tension. To balance this build characteristic, most boards will have twice as much glass on the deck as on the bottom.

On this particular board, another concept gets introduced. In a sandwich the stiffness increases exponetially with the distance between the layers of glass. So on my deck, I have one layer of glass under and one over the 3mm T400 Corecell. What I've created is a huge imbalance on the deck in comparison to the bottom. The deck of this board is super stiff and so the bottom of the board is absorbing all of the load, rather than it being absorbed by both the deck and bottom.

However, when this board lands from an aerial, the compression will be on the bottom and I have almost 4 times the tensile strength on the deck as I do on the bottom. That imbalance allows my 250 pound buddy to ride it without a heel dent, but my guess is that after a few aerial landings, the bottom will crease.

If I skin the bottom, then I'm back in balance. Both top and bottom of the board can share the load equally both while riding and landing from aerials.

[Surfdad]

On to the next build. This is a duplicate of the Surftech Tuflite construction. There is a raging argument that goes on in surfing communities that doesn't particularly impact us folks behind the boat. In the surfing community, molded or pop-out construction is taboo! For us, no one would ever consider a hand-shaped wakeboard or think for a minute that a molded wakeboard was somehow inferior to one shaped by hand. No so, along the coast.

Surftech took advances in saildboard construction and applied them to surfboard manufacture. The two most common complaints about surftech's are that they are too stiff and corky. Shapers, I do believe, mostly concur that the construction methodology is robust but also that the molded construction limits buyers. There are no custom shapes available.

The construction isn't all that hard. It's a lightweight EPS core that is shaped and then a high density foam skin is laminated to the exterior. The last thing that Surftech does is load a ton of paint on the outside. The finish is absolutely gorgeous!

Surtech's are built in the Cobra factory in Thailand, the same factory where Inland Surfers are made. The construction methodology is similar, but not exact, between Surftech and IS.

I don't have access to a mold or the ability to thermoform the high density skins. However, I did want to put to briefly demonstrate that custom boards can be made using this construction. The only real difference between my build and a Surftech, is that I laminated up Divinycell h80 rails, whereas Surftech/Cobra wraps the deck skin over the EPS to form the rails.

Garage built "Tuflite"/Surtech/Cobra blank on the left (waiting for final lamination and paint). That blank as 1/8" d-cell H80 skins top and bottom and 1/2" d-cell H80 rails. The core is 1# EPS, with 4 pound pour foam reinforcement for the fins.

[harv]

Surfdad, reading your posts makes me more and more curious about building one for myself. I know absolutely nothing about it and even less about materials. Are there any good books or dvd's about building boards that you would recommend?

The local board shop has been carrying liquid force molded and customs, but the owner is looking at IS for next summer. We're starting a learn to wakesurf program next summer and IS would allow us to buy 2 demos (a good price i think). I'm having the shop owner talk with TWP also, I really like the looks over the IS boards and after reading more of your posts, it seems like TWP has things more dialed in.

What are your thoughts?

[Surfdad]

Hey Harv,

The "bible" of shaping Polyurethane blanks is John Carper's Shaping 101, Glassing 101 and if you want to paint them, Airbrushing 101. Amazon has them in DVD and VHS, I do believe here.

The current blank of choice is EPS using epoxy to laminate. It's a bit tougher than usig PolyU. Greg Loehr is a shaping from years back and currently operates Resin Research Epoxy. He has a shaping and glassing epoxy series you can find here.

Before I plunked down any money, I'd go look at the Steve Pirsch's aka "Surfer Steve" great website How to build your first surfboard. Here is that link.

IS and TWP both make great boards, either of them would be far superior to the LF modified wakeboard wakesurfers.

Pro's and con's of each. The IS boards are a bit heavy. They are resin/paint rich on the outside and have a tendency to crack on the surface when whacked - it's an indication of more resin than fiber or NO fiber. IS knows the begginer market though. They make boards that just about anyone can get up on and ride. Good traction, good, if not great fins and the guys from IS are great to work with. Tough to beat for newbs and entry level folks.

TWP are responsive boards. It would be tough to outgrow even the stock entry level boards. Futures fin boxes allow you to swap in/out hundreds of different fin combinations and Mike places the fin pods with surfing in mind, not ease of manufacture or just for newbs. Mikes external laminations are pretty thick, so you won't get the "spider cracks" or chips like on the IS, but dings and heel dents still appear.

Honestly, I think either manufacturer would provide a solid board for an instructional environment. I'd negotiate with both folks and see who gave the better deal on the broadest range of stock boards that could be used in an instructonal setting.

[ragboy]

I think surfdad just like's heading to his workshop and catching fumes.

[harv]

Thanks surfdad.

i actually found the surfersteve site the other day. good info but left the no brainers like me puzzled in a few areas. i need visual along with the tutorial. i'll take a look at the links you posted.

funny. just after my previous post the board shop owner e-mailed me with info on TWP board orders. They'll work with us on orders and price. it's a bigger commitment level for the shop owner but he said that if i'll work my butt off helping him promote the boards, he'll do whatever i want. cool. the great thing about TWP is the custom graphics... we'll order the boards with the shop name and logo as part of the graphics. good publicity, great way to generate new custom orders.

[Surfdad]

I think surfdad just like's heading to his workshop and catching fumes.

You can't KNOW how true that is. It's a great diversion for me. In my practice, fully 60% of time is babysitting either clients or staff. This week I came in from lunch and found one of my employees, who SHOULD have been working asleep at her desk!!!! So to refrain from STABBING my eyes out, OR stabbing an employee in their sleep, I shape LOTS and LOTS.

Hey Harv, I know that Dennis and Mike have been doing the custom graphic shop names for about a year now. I know that folks will typically buy what they learn on, sounds like a great setup for you.

[ragboy]

I feel you. I sometimes get on my motorcycle, put on my helmet and head up the mountain and back to clear the old noggin.

[LovinPowell]

I go surfing.

[Surfdad]

Go LP!

Two updates on this latest build - how to lap rails with a bag - gather all the excess bag on the side OPPOSITE the lamination and pull it tight as the vacuum is being pulled.

This morning out of the bag and the board weighs exactly 30 oz. My goal is to have a finished weight of 3.5 pounds. Still on target.

[da.bell]

SD, the last picture is hard to see what you are trying to tell us. Can you explain what it is?

[Surfdad]

That I take CRAPPY pictures!

In the construction of a board, resin is what comprises the greatest propotion of weight. Further, a high resin content (vs. fabric) gives the lamination a higher attribute of the resin - that is, the board becomes stiff and brittle. In the industry, a REALLY good laminator can get resin to fabric ratios down to 1:1, although with fabric weights in the 2 oz range, it would take minimally probably 4 oz of resin to laminate by hand, or 2 to 1 in this instance. In aerospace and composite industries that utilize vacuum assit, that ratio is below 1:1, typically 60% fabric and 40% resin.

It's a common misconception that you can't lap the rails using a bag. It's not as easy as doing it by hand, but it can be done without a mold or rocker bed. This misconception is what tends to turn professional builders away from using this sort of technology...as most WANT the lower weight and tighter lamination.

The picture was an attempt to show a smooth, relatively balance lamination. Folks that build boards for a living, hopefully can appreciate the savings in resin usage (less cost and less weight) and also see that the rails can be lapped using just a bag - no mold or rocker table.

[Surfdad]

Flip and lam the deck!

[Surfdad]

And my next tool, in the process of being built.