News:
Many of our kits are now delivered with CNC cut jigs. The jig is assembled like a puzzle. In most cases, the builder does not even need a tape measure. The jig is self-aligning: it is very difficult to make a mistake.
Rebuilding the Aquasport Classic "flatback"
After measuring diagonals from chine to shear to make sure the hull was square, we made a mold for the new transom. It is basically a dam for the new outside skin. The dam is made from Melanine which is secured to a lip of original fiberglass left around the transom. The Melanine is coated with mold release wax and PVA. The clamps are only temporary until the dam is secured with screws.
Some small fillets of epoxy/woodflour are laid in followed by a layer of 6 oz cloth. This acts more like a skin coat and also makes a smoother surface for the 1708 Biaxial cloth.
A cardboard template of the inside transom is useful for cutting the 1708 to fit. It will later be used to cut the 2" foam core.
The 1708 is cut to fit and laminated into the "mold". Layers overlap 4" progressively. First layer goes 4" up sides and bottom, second goes up 8" and third (not in yet) will go up 12".
Next I have one more layer for the outside skin, then the core is bedded in, then the inside skin.
When the transom is complete, we will rest the hull on a cradle the will support it at the chine and keel – then we will put in the new stringers.
You
mention, in your tutorials, that when using epoxy as laminating resin,
that it is mostly not necessary to use matt when laying up yet in this
situation you are using 1708 which has matt with the biax. Why did you
use 1708 and not just straight 17 oz biax cloth?
When you tab in the stringers will you also use 1708 or will you just use straight biax cloth for that?
Excellent question! We want to build some outside thickness for puncture resistance (foam doesn't have much by itself) so the 24 oz total of mat on the outside is just added "bulk". On the inside skin you will see 17 and 12 oz biax without matt, some 45/45 and 0/90 will be used. If we used 1708 on the inside it would be a huge waste of epoxy for no added stiffness.
Just as a rough estimate, there is probably 5 extra pounds (2.25kg) of resin in that mat now - that's about $25 worth of epoxy.
For a wood core and epoxy, no mat. The lamination would be quite different for a wood transom.