Rikki-tikki-tavi... Vacuum Bag

The vacuum bag clamps the panel by pumping the air out of the sealed bag with a vacuum pump. We had a bit of trouble obtaining a seal for the first few panels and frantically raced around with clumps of putty and tape to close any gaps or pinholes along the edges or in the polyfilm we were using. Fortunately we did not lose any panels. We tried several manufacturers and weights of polyfilm. Finally, we realized that air was infiltrating right through the plastic itself! We had a custom vinyl top seal layer made. Getting a positive vacuum was from then on was a cinch.
Here you can see the stack of plywood strips in the foreground, our work table, and the mold with a large panel under the vinyl bag. The white line on top is the perforated PVC pipe that allows air to be pumped out and a vacuum obtained.

It usually took about 3-4 hours for the epoxy to cure. We started in the morning, the largest panels took the two of us only an hour and a half to lay up, then we set the vacuum quickly and waited. We'd pull the panel off the mold at the end of the day and fill the staple holes, ready for the next layup. It was quite easy for two people to accomplish.
The CC40 has 20 panels, 3 for each side of each hull, and 2 for the bow flares. The panels are aligned and assembled correctly with constant reference to a Prime Meridian- a line which is on the mold and is transferred onto each layer of the panels as they are layed up. The plans do not come with full size patterns. There is a set of offsets using this Prime Meridian which the builder uses as the basis for creating for each panel and trimming it properly. The panel's position on the mold determines its curve.

The mold has an airfoil shape athwartships and a curve lengthwise that, if one were able to extend it, would come together into a complete circle. This particular mold makes only the CC40, but some other Constant Camber® molds may be used to make more than one of John Marples' designs.

a Raw Panel Just Off the Mold...

It usually took about 3-4 hours for the epoxy to cure. We started in the morning, the largest panels took the two of us only an hour and a half to lay up, then we set the vacuum quickly and waited. We'd pull the panel off the mold at the end of the day and fill the staple holes, ready for the next layup. It was quite easy for two people to accomplish.

The CC40 has 20 panels, 3 for each side of each hull, and 2 for the bow flares. The panels are aligned and assembled correctly with constant reference to a Prime Meridian- a line which is on the mold and is transferred onto each layer of the panels as they are layed up. The plans do not come with full size patterns. There is a set of offsets using this Prime Meridian which the builder uses as the basis for creating for each panel and trimming it properly. The panel's position on the mold determines its curve.

The mold has an airfoil shape athwartships and a curve lengthwise that, if one were able to extend it, would come together into a complete circle. This particular mold makes only the CC40, but some other Constant Camber® molds may be used to make more than one of John Marples' designs.