Carbon paddle blade build

[Vawtec]

I broke my paddle and cant replace just the blade. Like the shaft and adjustable handle so I'm building a blade.
Making a spine core out of 3/4 polyurethane foam. It will have the blade angle and slight scoop at the tip.

[Vawtec]

Two core halves tack glued together with 5 min epoxy. Starting to shape the foam.

[Vawtec]

Foam easily sands down to fiberglass web. Rounded nose to fit in shaft.

[Vawtec]

Split apart the two core halves. Each will get a carbon braid. Heavier braid will go over entire assembly

[Vawtec]

All the material and bagging material laid out.
Wetted out core and slid on braid. Braid tightens up on contour as you pull it.
Wrapped 2 core halves together with carbon tow

[Vawtec]

I put some uni carbon on the cores top and bottom, not seen.
Whole assembly wetted with epoxy and slid into outer braid.
Braid wrapped with carbon again to hold contour

[PonoBill]

Nice work.  If it doesn't turn out the way you want it you could use a Ke Nalu blade. It would be pretty easy for a guy with your skills  to adapt it. The blade is the most difficult part by far to make. Generally you need  high pressure molds to make repeatable patterns that are light.

[Vawtec]

Cured spine, out of bag. 4 oz

[spookini]

Kinda reminds of the time I decided to replace my damaged workvan's hood w/ a custom replacement hood fashioned out of bean-and-cove atlantic white cedar strips. 

In the end, $80 bought me a new used hood at the salvage yard.   

[Vawtec]

Blade cores cut a bit oversized and 5 min epoxied to spine.
Core is almost flush with power face of blade.
On backside, spine is recessed in unshaped cores.
This gives me a flat reference on the back side so I can shape the power face.

[Vawtec]

Shape of power face done.
Slight dihedral and scooped tip.

[Vawtec]

I layup the 5.7 oz biax carbon on thick mylar. The mylar comes off after the vacuum bagging and leaves a glossy surface
The carbon/mylar layup is aligned with the core, then bagged.

[Vawtec]

Blade with power face laminate in vacuum bag
Backside of core is unshaped and still flat. I use this surface to weigh down the blade until the epoxy is cured.
2 days work so far.
 

[blackeye]

When you form the foam into a plug for the shaft insert, how do you ensure the shaft and spine will align?

Do you hand-shape that part?

[Vawtec]

It's all hand shaped. Eye balled from the broken paddle. The plug end will be a bit small so I'll have some wiggle room to align the blade and shaft