Simple and cheap vacuum chamber. I used a thick glas jar and a thick sheet of plastic as a lid. I applied some rubber from a car tire to the plastic using tacky tape.
This time using the bag (with a simple diy vacuumconnector)
Result:
No air bubbles can be seen with the naked eye. I am not able to get a nice flat finish, the bag pulls in between the fiber yarns showing dents and revealing the treads connecting the fiber yarns. I need a rough surface since I will be doing the glassing in multiple stages. Sanding is not an option since I will damage the fiberglas yarns. Peelply will be the solution here.
I ordered some peelply, bleeder and breather fabric which I will use for the third test sample. It seems that I am able to pull a pretty even vacuum on the test samples. But I feel that the board will need a breather fabric to acchieve an even vacuum distribution since it has a much larger surface area.
The air pressure will most certainly be enough to from the rocker Zob; surface area is around 0.5 m^2. Assuming a 90% vacuum gives an air pressure of 90000 N/m^2. This gives a force of 45000 Newton on the board which is equivalent to a mass of 4500 kg. But, I am using a bag! So I need to get creative with some clamps.
I don't really understand the thing about the waterline and the need for a strong topsheet downunder. Could you please explain?

Do you guys have any tips/recommendations for the edges? I feel like the fiberglass+epoxy layer will be exposed to the water since it is laying on top of the sidewall...
