OK. First step done. I managed to hotwire deck and bottom out of a leftover block from the last board.
The bottom is a bit wobbly. Now I'm not sure if I have to sand the wobbles out altering the rocker or if it will be pressed flat when adding the bottom sandwich sheet. I think about the latter. As the bottom will be spackle anyway after the sandwich I can get rid of any remaining wobbles then. Here is a rather bad picture of the hot wired bottom. You can see the HD foam for the rails in the back.
The conventional wisdom here is that you can almost never fix a problem with the next step of your process. Work each step as cleanly as you can. If you haven't done the deck yet then the worst thing that can happen to you with the above is that you'll move your rocker template to give you a little more room to work with. You can clean your wobbles with a long sanding block and long strokes. Those wobbles will clean right up.
Fix the bottom, then when you cut the deck leave yourself a little room so you can sand to your line.
You're right gdaddy!
If it goes well it'll save me 10 minutes with a sanding block. If it does not work it'll be a hassle with spackle and much more sanding.
The deck is already cut. I'll just sand out the wobbles. As I have decided to go with a flat bottom I will press the bottom sandwich against a rocker bed. Still have one from the last board without the wobbles. I don't think sanding of less than a millimeter on the bottom will change the deck noticably.
Next step won't be befor november. I'm wainting for a lasercut outline template.
Has anyone of you ever finalized the outline using a router around a template?
I consider the routers to be the most dangerous tools we use. They're scary enough when we're doing fin system installs; I'm not going to press my luck with using one to cut 20 feet of template line with one. Some veteran shapers use a router, but most don't.
For now, just stick with a saw. Until you get your sawing technique perfected you can cut 1/4" outside your line, and use a planer or sureform and sanding block to clean everything up and get that cut square. It takes a lot longer but you retain more control that way. Besides, you're not on the clock. You don't need to be fast. You only need to be clean.