Like a good shaper shaping the channels, a good glasser can do it in one batch like a normal glass job.
However…the big however…if you aren’t experienced then you might want to try something I did when I first started.
Mix a very small batch of resin and just laminate along the shaped channel areas, so that when you are ready to fully laminate, the channels are already stuck down and won’t give you problems.
I found this a really good way to learn how the glass and resin reacted around sharp corners, and how to keep it in place without too much drama. And it gave me time to make sure the fabric was stuck down while the resin gelled enough to hold it.
Another spanner in the works is dependant on the softness or stiffness of the fabric you are using. There are some fabrics I would never use if glassing channels.
If in doubt, do a small test on offcuts. Quick, cheap and easy.
Someone asked me some questions in a PM that reminded me of a few things I forgot to mention. It is pretty easy to test out channels by filling them with wax. The wax won’t effect the flex but will alter the water flow so you can feel if it is the water flow or the flex that is effecting the feel of the board. Or a little of both. You can lighten it up if need be by adding some micro balloons or Qcell.
Also, be cautious of the outer channel’s depth and location as creating a big claw on the rail can have some unusual effects on performance.
One of my worst wipeouts ever was the first time I rode one af Alan's big wave deep six. An amazing, sleek beautiful 9'0" gun with his cutout fins. Made the drop, hesitated and then attempted a powerful backside bottom turn. Board kept going straight and I was drilled by the lip and hit bottom. Down there for too long, I still remember and it was over twenty years ago. Pilot error no doubt.
Lesson learned, they ride different and take some getting used to. Bill's stiffness theory makes sense. Aloha
Cort Gion! ---------- One of Ten. But IMHO channels were nothing more than attempt to get single fins and twins to function more effeciently. They went obsolete with Simon Andersons "Thruster" and while aesthetic are now nothing more than an artistic novelty. Lowel