Namaste Arborial Aquaphiles, and welcome to this installment of building a Nine-One Mal called.....well I don't actually have a name for it yet but I'm open to suggestions. It's a bit of a dilemma naming a board. Well is it for me. A bit like deciding on a name for your kid but not really. I mean there have been some shockers in the kid naming space. Arthur Brain, Dwayne Pipe, Gaye Males, Jack Goff. I mean what were their parents thinking? Kids names are a little more critical than surfboard names though. Stuff up a kid's name and poor old Jack Goff will never hear the end of it from his mates in the school playground but go with a lame board name and probably no one will even raise an eyebrow.
Anyway, there's a prequel to this epic. I still get a little emotional telling it so bare with me. This wooden board was originally my second, and it started its life as a hollow wooden version. It all went terribly wrong the moment I attempted to use my vacuum pump and bag to put the deck and hull skins on. I had spent and inordinate amount of effort and time measuring and scribing out the plans on butcher's paper, and meticulously building the frame. Then came the day to glue the skins to the frame. Being the cautious bloke that I am I decided to do a dry (glueless) run first. I taped the skins to the frame, slipped it all in the vacuum bag, sealed it up, connected it to the pump and sucked the bejesus out of it. Now my pump pulls a vacuum close to one atmosphere of pressure, about 27" of Hg (mercury) which is a lot for a hollow wooden board. It was all going gang busters when I started to hear the sound of the board creaking and groaning under the pressure of the bag, kind of like a U-Boat that's been hit by a depth charge. As the skins started to bow inwards between the frame ribs, I thought to myself, "Wood Buddha, this can't be good". At that moment and as I dove vertically through the air to do an emergency disconnection of the vacuum hose, kind of like a Wallaby scoring a try (which is rare these days), I heard a loud "CRACK!" and what I ended up with is a crushed board.
I sulked for month!
The following pictures tell the story.
Now we gotta make the best of it, improvise, soldier on, adapt, modify, overcome, Darwin, I ching, whatever man, we gotta roll with it. Acceptance of the impermanence of life and all that other Buddhist shit. Whatever! Mrs. Wood Buddha gave me a few upper cuts and I crawled into a corner and took a dog with me to lick my wounds.
Back to the story. So what I was left with was a frame with numerous crushed ribs, and deck/hull skins with several fine cracks about 500 mm long. The frame was pretty much a write off so I hung up on my ashram wall to remind me of past failure and keep my ego in check. I decided the skins were worth saving. I could build another frame but I was keen to try another technique developed by Grant Newby of the Gold Coast and currently adapted by Firewire Surfboards for their Timber Tek range. A Paulownia skinned EPS core surfboard.
The first part of the process was to design the full board with final dimensions in AKU Shaper. Once I was happy with the outline, profile/rocker, rail profiles and volume I saved the board file. In this case I named the board "mymal91.brd". Maybe that's what I should call the board, "My Mal"? Pretty lame really. I then opened the exact same board file in AKU Shaper and renamed it something different like "mymal91EPSCore.brd". This is the EPS core that I'd get shaped on an APS3000 machine. I then loaded the original mymal91.brd file as a ghost board and used this as a guide for adjusting the outline, profile and rails of the EPS core. I allowed for the 6 mm paulownia deck and hull skins, and 24 mm (6 x 4 mm) all around the outline for the rails. I also squared off the rails. Now this all sounds a little complicated, but once I got a bit of practice with AKU Shaper it wasn't that difficult.
Some screen shots.
The outline in AKU Shaper.
The board profile/rocker.
A view of the centre slice with a fairly full rail. The bottom contour rail to rail is fairly flat. It transitions from a concave in the first half of the board to a slight roll in back half of the board.
The slice 300 mm from the board tail. There is a slight roll on the bottom contour of about 4 - 5 mm.
The slice 300 mm from the nose. Note the bottom concave.
This is the EPS core file. The original board file is imported as a ghost board and has a white outline. The EPS core board is reduced by 24 mm all around to allow for the paulownia rail bands (6 x 4 mm).
The view of the profile/rocker with 6 mm taken off to allow for the paulownia deck and hull skins.
The centre slice with squared off rails.
The slice 300 mm from the tail with squared of rails.
And the same for the slice 300 mm from the nose.
The next stage was to email the file to the guys at South Coast Foam at Burleigh Heads to cut the blank. They cleaned up the file in their machine version of Shaper3D, removing any lumps and bumps, and cut the board on their shaping machine using an EPS (Expanded PolyStyrene) blank. The blank is rated at VH (Very High/Hard) density and has a stringer pre-glued into it.
The view from the tail. Already finished.
The rails have a bit of a lip but are easily cleaned up with 80 grit sand paper.
Home made sanding block with right angle guide and 80 grit paper hot glued to the block.
Using the sanding block to get a nice square edge.
The nose neatly finished with some light sanding.
The EPS blank weighs in at 2.2 kg. The original timber frame was 2.25 kg but I could have made it a bit lighter by using a 6 mm paulownia stringer and not using solid nose and tail blocks.
The blank tail was neatly finished and didn't need any additional sanding. The rail edge is square after some light sanding. No need to sand the deck and hull. These will be covered by paulownia.
The panels thicknessed to 4 mm measured with my Dad's set of vernier calipers.
After 20 minutes in the pot of boiling water the rail bends easily around the nose. I taped it in place for an hour.
be planed down to the top and bottom contours of the board.
I just cleaned off the old glue with sand paper, re-glued in it and taped it into place.
Marking around the nose.
The tie down strap.
The bag pulls a nice concave.
Trimming the sides of the skins. I take my time with this part of the process and use a nice sharp plane and a sanding block.
Ready for the rail bands, centre fin block, side fin plugs, leash plug, rail shaping, final sanding and epoxy hot coat or lanolin. I'll cover this off in Part 2.