daspi, I know, you think there is much more work if you use ABS or pured epoxy rails, I thought that's true too, and did my first 4 boards with overleaping the edge.
But like lawless mentioned it is almost imposible, to do this perfect and by overleaping like in surfboard production, you will make the edges much more stiffer and that you don't want.
So there's another variant I did. I laminated the top first and overleaped just the edge and not the bottom (and it would be imposible too, because the board was on the rocker table). So, as you can see from the picture there is from perfect bond to the edge to no bond at all, so you have to fill the gap with epoxy and wrap the board with tape, forcing the coured laminate to the edge and after couring and removing the tape there are still some gaps, you have to fill with epoxy. After this long proces you just laminate the bottom straight.
The look of the edge from the upper side:
You could probably do this better, if you laminate w/o vacum bagging and no rocker table, but that way it is harder to do the surface good, so I don't realy think about hand laminating. And there is a big probability, that sooner or later you will hit a rock or drop the board on the edge and damage the laminate and the core will be exposed to the water.So this is how I do it now!!!:
- pured epoxy rails
I cut a pattern with finished board shape and seal the edge with a tape, so the epoxy won't bond to it, I cut the bottom core layer smaller (1 cm arround), than mark the core outline to a stiff board and tape the line with two-sided tape (why? later!)
I position the pattern and the core to get the same gap all around and than use a tape (main reason: epoxy won't force out) to get them together.
Than you position this on the stiff board you prepared earlyer, tape facing down.
Explanation of the two sided tape:
Because the tape, you used to get the pattern and core together is wrinkled, you straighten it out by sticking it to the two sided tape.
Than screw or weight down the pattern and the core.
I fill the rail gap with choped strands, mix the epoxy with microbaloons and some cotton flakes (for epoxy to harden faster) and pure it in with injection, because it is easyer to dose, or there will be a lot of mess (and later sanding too). It is god if the pattern is a litle bit thicker than the core.
I hope you understand my discription of this process.