So i spent all this time shaping, concaving, channeling and reinforcing my shaped blank…but it’s got no rocker!?
cutting it and adding a stringer will not doubt screw it up
Vacuuming down to a table will crush the concave
I pre-cut the 1/8" d-cell so that it would conform easily to the channels and not crush them
I filled the swiss cheese 0.75lb foam with a slurry of micro-balloon and epoxy. You see a messy blank I see a fantastic surface area for bonding.
laminated the core in 4.5oz carbon with 6oz unit @ 90 degree under the impact zones
placed the corecell on top.
Then put the assembly in a vacuum bag. with some release ply oround the rails and some recycled breather.
I put it in at 15-18 inches HG over 20 I get serious core crush using a vacuum controller
PAY ATTENTION here is the trick.
I used long narrow custom made sand bags to conform rails of the the board to the rocker table. The vacuum forces the assembly into concave and channel shape you made while the weighted rails force the rocker into the board.
For anyone who says “that’ll never work”…close your eyes…
As mentioned I have vacuum control. I forget what I used. but it’s a cheaply purchased adjustable vacuum relay that just shuts off power to the pump. It has an 8 In HG window where it will keep the pump off. I set it to turn off just below 20 inHG and it seems to work well.
To make this effective without a perfect seal I have connected my vacuum pump (robinair) to an air reservoir (from a broken compressor) and added a check valve.
The pump likes to smoke and mist oil all over the shop so I exhaust it out the bottom of the garage.
You might also have noticed my heat box.
it’s got CPU fans to circulate the heat and is temperature controlled to allow post curing, building in winter, or speeding up jobs and ensuring complete cure between sanding coats.
I’ve got 2 temp controllers on the box + the heater has it’s own internal over temp protection.
in addition if the heater falls over it switches off.
The foam is poly-iso which is the least flammable foam available. and is foil coated…
still sketchy as hell but a lot systems have to fail simultaneously for it to all go to shit.
I’d make the box out of drywall and roxul insulation but I need to store it in my rafters when I’m not building stuff.
5 mil poly, a hair straightener and some parchment paper, can make a sweet custom bag.
Make the bag as BIG as possible. it allows you more freedom removing wrinkles and makes it last longer, most times I have to cut off the end I seal.
Thanks for posting this ! May I ask a few questions? You obviously have a rocker table in your hot box, is it adjustable or do you build one for every project? How do you actually heat the box? Could you explain the custombag trick in detail? Many thanks again, I am looking forward to the next episode!
I’ll do a separate post about bagging with a hair straightener. My bag is nearing end of life. and will need to be replaced soon. So I can do it up proper with pictures and some small tips to make it work well.
Back to the build. cutting spectra is not easy. scissors don’t work and if you do happen to have an ultra sharp pair around they usually still make a frayed mess of the edges.
So I used my hot wire cutter.
This has the beautiful effect of cotterizing the edge so that it will not fray no matter how abusive you are in the lamination phase… I wish I could do this with all fabrics.
I don’t take photo’s of laminating as I’m on the clock trying to get it bagged before the resin kicks.
I often laminate in the cold and then throw it in my hotbox and ramp up the temperature with extra breather and perf ply to suck out excess resin. This gives me a long working time. to get the fabric laid down perfectly I’ve always been able to lay down all layers and 1 shot the board having it come out of the bag complete saving time and consumables.
I made two critical mistakes…
I used a different resin. Resin research as opposed to system 3 medium cure.
I’m using a different material spectra instead of fiberglass or carbon.
This led to a bunch of problems
The tight weave to of the spectra was impossible to wet out due to the cold. All the trials I had run were in the warm. it took me a long time to get a translucent fiber.
The spectra would not hold to the rails. it kept pulling up as I tried to wrap it.
The resin kicked way faster than in the cold than the stuff I normally use. this solved my rail sticking problem but I used so much resin to just wet the fabric out that I was going to have to pull a ton out in the bag.
Exhausted at how long the bagging took I was overcome by my ADHD and I forgot to put my thermocouples in the box so the heater thought the temperature was -5 while the box temperature climbed to around 70C where the heater shuts itself off.
As a result of the high temp and rapid cure, none of the resin had time to be drawn out into breather…
Furthermore EPS doesn’t like temps >50 and I melted the foam in the nose of the board closed to the heater that left a blister.
The “ultralight” board weighed 3400 grams (expected weight was 2100g)
and needed a full pour foam core repair prior to even getting on the water.
Complete and total fail of core purpose…
When I realized this I sat on the floor head in my hands and was about to scream out the world’s biggest FUC%!!!
Then the door from the house to the garage (which is NEVER allowed to be opened) opened and my 5 year old daughter stood there confused at me sitting on the floor of the garage looking visibly disgusted
“What are you doing daddy?”
“Trying to make a surfboard”
“I want a surfboard, When are you going to make me a surfboard?”
“How about right now…”
The tight weave to of the spectra was impossible to wet out due to the cold. All the trials I had run were in the warm. it took me a long time to get a translucent fiber.
To laminate tight fibers, you need a wet out table.
I call it the “taco” method.
Lay out the cloth on the plastic covered table.
Cut the cloth to size and template.
Fold the cloth in half, nose to tail.
Pour 1/3 of your mixed epoxy onto the plastic, not on the cloth. Unfold the cloth to cover the poured epoxy. So the epoxy will start to soak into the cloth from the bottom.
Pour 1/3 of your epoxy onto 1/2 of the cloth. The side that already has epoxy soaking in through the bottom. Now fold the dry end of the cloth over the already wetting out half. so you now have a cloth taco, with wet epoxy under it, and also between the layers.
Pour the remaining 1/3 onto the cloth.
nothing should have been squeegeed yet.
lay a layer of plastic over the wetting cloth. Now start using the squeegee to spread force and spread the epoxy around to saturate. Two reasons for the top plastic. a) it keeps the cloth from being dragged around and distorted. b) it keeps the epoxy from frothing as you move it around. No air means no froth.
squeegee any extra epoxy out to the edges, and out of the cloth. Not with too much force, but enough to remove ant wasted extra.
throw out the top plastic, and unfold.
Pick up the cloth, and lay it onto the Board. You can to this by having a helper lift the cloth, or get some 4" plastic drain pipe, and roll it up onto the pipe. Then unroll it nose to tail onto the board.
Bag it.
I know this all sounds really complicated, but once you do it, it is really easy. Do a dry walk through first, to make sure you get your process down.
I can’t draw anything for crap so I wanted to make some stencils
found some images online she would like.
Converted to SVG using the following website http://image.online-convert.com/convert-to-svg
Imported into freeCad program of choice (Autodesk 123d tinkercad etc) , Extruded it up to make a stencil and converted to STL so I could print on a 3d printer.
To understand if this exercise was worth repeating without the screw ups. I waxed up this wall hanger and took it out in 10ft windswell with my kite…
Turning:
Turns incredibly easy even when going scary fast down a bomb of a wave.
Speed: very fast board And early planing could shoot down the wave face and get crazy speed, kite upwind at high angles or just hold my place on the wave and slowly ride it at speeds lower than I’m able to stay on plane on my other boards.
Stiffness: this was the part I was worried about , but with all the concave the board is not rough to ride. Better than my current board which is very flexible There was 1 or 2 times I hit the wrong piece of chop and it felt like neither the board or the wave wanted to give in the collision and so I nearly got tossed over the nose this only showed up in the chop between waves and not on the faces and maybe 1-2 time in 6 hours of riding
Pearling: never dug the nose in.
Ovearall:
Rode as good as the Vader or better after my first test drive I grabbed my old board to ride…so as not to break my daughters birthday present. After getting off the pink flowered unicorn board and onto a more respectable ride…I realized it made all my boards feel like a bag of shit wrapped in Fiberglass…these are good boards…they’ve out performed all boards I’ve compared then to and .I’ve sold many copies to customers who absoulutely love them …however they lack the unicorns and flowers of this mythical ride
The wind was good the swell was good, after being unable to adjust (downgrade)to my old board after a few waves I went back in for the unicorn…and finished an epic 6 hour day of riding on it. Lots of airs tumbles punts and beach washups Nothing more than microscopic surface scratches in the clear coat from my feet grinding dirt into the deck.
