Following on from making mats in various forms, I found mats are fast but essentially uncontrollable in the way other surf craft are.
Some of the mats I’ve made had a hard deck with a fabric hull and they kept the mat speed but I could turn when and where I wanted and this needs to be followed further.
The plan is to make the deck like a Spoon kneeboard with layers of glass over a foam form making a hard yet flexible deck. The planes and angles of the deck will control how it flexes. The template is a rounded rectangle with added nose length. There’s a domed deck, bevel rails down to a flat perimeter track that’s needed for the fabric to be attached.
Then add the inflatable hull skin.
Shaping the foam core is interesting as it’s going to be a male mold that I’ll vacbag glass over and then pop the shell off so it could be used several times if I’m careful.
Oh yeah, I’m interested in hearing how this project turns out. How will you connect/secure the mat fabric to the board? And aren’t most mats turned using a combo of lean as well as squeeze/release of the mat material? How will yours be turned? Since most mat riders use an under inflated mat, what amount of inflation do you expect your mat will be?
Jrandy, I initially thought of thermoforming a plastic sheet over the mold but the size is beyond my current capabilities so I thought I’d do a few prototypes over a foam mold, vaccing maybe 2 layers of glass at a time.in the end having a glass only shell to attach the fabric to.
Monkstar1 the fabric is easily glued to the flat perimeter area in the pic below. I made a lot of mats here under the name Ultimats and even a strip 1 inch wide is sufficiently strong to hold in the surf.
i did a lot of experiments with inflation values and it’s interesting that even a 1/2 filled mat that looks floppy will increase its internal pressure very high once you lay on it.
Turning seems to be all about the rail, you’re weight is focussed on the inside rail and that’s where the hard but flexible rail comes into play. I’ve made a dozen variations of this before, with and without fins on the rail and it’s amazing how significant the flexible hull is for speed but also how controlled turning is with even a 1 inch wide rail.
With the outline done, its time to profile the thickness.
Because the nose has less width, if I also thin it out too much it won’t have enough buoyancy and will lose the incremental fore/aft balance that boards have .
So there’s a basic nose rocker of 1 inch that’s more for aesthetics and I’ll taper the deck so it’s 2 inches thick at the front and 3” in the middle and 2.5 inches at the tail.
Puts a slight dome on the deck that places more lift under your torso and slightly less at the nose, tail and rails for easier turning.
Hi surffoila it’s great to see someone implement this idea . We were discussing it back in the day . It’s still in the back of my mind I think the mat should inflate into the board to secure it . So the rails would have to curve over . Also to implement a fin system would be a good idea . Could be very simple as simple as a plywood box
Paul, with mats being fairly static in design, materials, construction or innovation it seemed like a ripe field to run through.
im sure I’ve thought of the mat in a box idea too, mats are so fast yet uncontrollable that any form of control is going to be a Good thing.
Accelerating forward with the ply box idea , I’d probably think of joining the box and mat at some level.
I made glassed foam deck lids that has positive buoyancy and I glued fabric onto them but this is a further step forward with just a flexible shell as the deck. Without inflation it will have negative buoyancy so it’s going to be different. Unless anyone else has seem this sort of thing before ??
It’s designed to have room in the perimeter channel for FCS plugs or maybe a Universal Fin Box , if that’s been invented lately ?
I found that fatter rails don’t hold especially on steep waves because the volume is too high. So if I take a calculated amount of rail volume away it should hold better and allow me to sink a rail into a turn without popping or skidding.
So it’s almost shaped. This carapace or shell will control the distribution of the air and how the craft turns , it also creates a curved shape that should prevent buckling but allow torsion so I can twist the craft from rail to rail to fit the curve of the wave.
If I can get if to flex about 10 degrees difference from nose to tail it should allow the nose to be angled into each Turn but keep the tail section flatter for driving.
It’s based more around the flexibility of the deck so I’ll change the Thread title to Flexible Deck Inflatables.
On the deck an even curve to distribute the volume. A little less volume in the nose for duck diving and keeping a fair amount in the tail for drive out on the face.
I’m not going to glass it like standard moulds. As the moulds outside surface becomes the inside of the craft, it doesn’t need a class A finish. I’ve got it on a rocker table and I’ll put a polyethylene bag over the mold and then vac glass over that.
Hi Greg, mats are about 3 inches thick and so is this craft too. I didn’t want it to flex too easily or not enough so I’m going to vac 12 layers of glass like on Greenoughs spoon boards to see how rigid or not the shell will be.
When flexing becomes snapping I want to avoid so I’ll try 12 layers and add if necessary.
This is just the mold that I’ll glass over and then pop the shell off and ride that.
