From Scrap Foam to Flying: Oliver’s Custom Carbon Pump Foil Board
Four days of pump foiling on a kiteboard was enough to identify the exact problem: too long, and the bow kept slamming into the water on every pump stroke. The commercial fix would have cost around €900. Oliver’s fix cost a pile of scrap foam already sitting around from the Paikea refit, and about a week of genuine composite work.
Starting with the shape, before touching resin
The build started with blocks of scrap foam, glued together into a rough billet with the same fairing bog used on Paikea’s interior — with one deliberate material change. Where structural bog on the boat cures to a fully hard, non-tacky finish, this batch needed to cure the same way for a different reason: since the board would be laminated in epoxy and carbon over the top, having a completely cured, non-sticky bond between foam blocks mattered more than raw strength. The joint only needs to be as strong as the foam itself, not stronger — over-engineering a foam-to-foam bond that’s about to be wrapped in structural carbon anyway would be wasted effort.
Shaping came next — pure hand-eye judgment, marking lines directly onto the foam block and cutting to them freehand. Not every cut landed perfectly; some sections came in a little wide of the line, others cut close enough that there was almost no room left to sand back to a clean, smooth edge. Real mistakes, made and worked around rather than hidden — exactly what a first composite build genuinely looks like.
Follow the first part of Oliver’s Build here: Boat Scraps to Foil Board: A 14-Year-Old’s First Carbon Fibre Build
A 3D-printed tool with a purpose that wasn’t obvious until it was needed
A small 3D-printed radius tool, made weeks earlier with no clear application at the time, turned out to be exactly what this board needed — used to mark a consistent radius along the front and side edges. That radius isn’t decorative. It’s there so the board can release cleanly from the water surface if it touches down mid-pump, rather than catching and dragging. The back edge deliberately skips the radius entirely, based on direct experience with inflatable boards where a radiused tail edge does the opposite of what’s wanted — lifting water and sticking the board to the surface rather than letting it release.
Mounting hardware: holes and tubes, not a plate
Rather than a single mounting plate, the board uses fibreglass tubes set into drilled holes to carry the mounting bolts — a simpler approach than machining a full base plate, and one that avoided rail-track hardware considered too complex to fit with the tools actually on hand. The tubes went in rough-cut, visibly scorched from the cutting process, bonded in place with bog and left to cure before being sanded flush and smooth — proof that a slightly ugly intermediate step doesn’t need to compromise the finished result, as long as the fundamentals underneath are sound.
Laminating: getting the resin ratio right, by weight
Before any resin got mixed, the carbon cloth itself was weighed — a simple, direct way to calculate how much resin the layup actually needs, rather than guessing. Under vacuum, roughly half the resin content by weight of the cloth gets squeezed out during bagging — not wasted, but deliberately redirected into filling the foam’s surface cells and soaking into the peel ply and breather layers, leaving the cured carbon laminate itself closer to 45% resin content rather than the 50% it started with. Weighing the cloth first, and working the resin mix backward from that number, is a simple, repeatable way to get a laminate that’s neither resin-starved nor unnecessarily heavy.
Two hardener speeds — fast and slow — got blended roughly 60/40 to land on a working time long enough to complete the layup properly in a warm 25-degree cabin, without the resin gelling before the job was finished. Getting that timing right matters more than it sounds: too fast, and there’s not enough working time to get a clean, bubble-free layup; too slow, and warm ambient temperature stretches the cure out further than intended.
Areas destined for the vacuum bag’s tacky tape seal had to stay completely free of stray resin — get resin on the surface where the tape needs to seal, and the tape simply won’t stick, risking the whole vacuum bag’s integrity partway through a layup that can’t easily be paused once it’s underway.
What We Used
Materials for this build came from Easy Composites EU (@easycompositestv):
- PVC Closed Cell Foam
- EL2 Epoxy Laminating Resin
- Carbon Fibre Cloth (200g twill)
- Breather Fabric
- Vacuum Bagging Film
- Peel Ply
- Tacky Tape
- Perforated Release Film
A note on the cloth weight: we’re still refining this build — there’s some flex in the finished board, and a heavier cloth may be the fix on the next one.
From the workshop to a canyon
Finished, weighed, and mounted with a foil, the board went straight to genuine use — including a trip to the source of the Turia River, where Oliver pump-foiled the length of a canyon on the board he’d built himself. Link to the canyon pump-foiling video here: Canyon Foiling with SABFOIL Blackbird
Why this matters beyond one teenager’s hobby project
A 14-year-old building a genuinely structural carbon composite part — correct resin ratios calculated by weight, vacuum bagging technique, real material decisions made and explained along the way — isn’t a novelty. It’s the same fundamental process used throughout Paikea’s refit, just scaled to a much smaller, faster project with an immediate, visible payoff: paddle out, pump, and go.
Follow Olly’s obsession with everything foiling here on Oliver’s YouTube Channel