Left: Paipo rider, Sunset Beach, 1965. Right: Val Valentine and Paipo board, 1965.

I watched Val Valentine as he made a Paipo for me in Hawaii, and could see that there would be a better way of doing it. 
He used a moulding surface to shape the bottom of the board. 
This was formed in earth outside his house, and lined with cement mortar. 
He laid vaneers of timber in this with glue between, then pressed the whole thing with sandbags on top.    When the glue had set, he trimmed and finished the board.

Concave tails to boards were all the rage that season, and Val was spending much of his time trying to build a concave Paipo that would work. 
I could see that this was not working out at all, and returned to Australia with one of his regular (non concave) Paipo boards.

Back in Australia, I built a press that had a concrete base mould at table height, and was loaded with a hydraulic powered airbag. 
This makeshift thing ran off mains water pressure and put over 20 ton pressure on the boards while the glue set.
Looking back on it, I was lucky that the thing never exploded.

I started using timber vaneer, but was unable to get suitable quality of material. 
I then tried using layers of eighth inch thick hoop pine plywood, and found that with the extreme pressure that I could form the two way curve (shallow dome) at the nose of the board. 
By putting plastic sheet between, I was able to form 3 boards in the press at a time.

With the stresses in the plywood, the curvature at the nose was less than with the timber vaneer. 
By chance, this turned out to be just right. 
The boards were a lot faster than those made by Val, but the nose never went under on takeoff. 
Because the shape of the board is set by the concrete base mould, trying out new shapes is a lot more difficult than when shaping from a foam blank; so I counted myself lucky to have done so well.

I was never an obsessed body boarder, and used all types of boards. 
Even so, the finless flat bottomed Paipo is still my favorite. 
You can get out through the wildest surf by swimming with the board under waves (the Paipo only just floats), and once you lever yourself onto a huge wave, the rigid flat finless bottom will give unbelievable speed. 
Turns are made by moving to one side and tilting the board onto that side rail.        Turning is an art, and if you lose your grip on the water, you will spin out.

Skid Board by Farfor Products, 1968. Images updated in April 2019  thanks to Ant: after all the old wax was removed and a few new coats of bees wax applied.