The wood of choice is glued together or one piece of massive lumber and afterwards shaped with a router on different jigs from top and bottom. It's quite a mess, but works pretty well.
Laminated plywood & veneer the fake vacuum method
Several layers of thin plywood are laminated together with a top layer of american walnut veneer. While the glue drys, the handplane will be strapped to a negative form in order to get the concave right. Once dryed, it will be finished with several coatings of marine varnish.
Steam bent hardwoodthe "hottest" method
This method was what I initially wanted to build the handplanes from. I soon realized that steam bending wood is not as easy as it first looked, so this is the future...
The objective is to get a deep concave for maximun lift and holding power on the wave face. This will be accomplished by one of the three solutions above.