Hi,

I'm a teacher and work with teenagers and am considering building a kayak with one particular class group. I already have a mould from which one successful polyester/glass boat was pulled about two years ago. The mould is also polyester/glass with a polyester gelcoat. The mould needs some minor modifications to change aspects of the kayak design that have become apparent in the meantime. Basically, I'll need to cut six slots, remove some material and then re-glass up the mould to make it rigid again. The total area of the modifications will be 6 slots each about 1 inch by 3inches. I intend to make the new boat from resin infused epoxy with a mixture of reinforcements including carbon, diolen, glass and kevlar with soric as a core material.

I understand that a polyester mould is risky to be using with epoxy, so my first question is whether the epoxy compatible gelcoat will lessen the chances of the new component sticking to the old mould?

The second question is whether I should use other materials to modify the mould to prevent there being any fresh polyester in contact with the new component? (if so, which materials?)

Third question, what release agent should I use? (the mould has a good finish and was well prepared with release wax previously),

Thanks,

Donnacha.

Thanks Matt,

One final question, is there a limit to the number of layers that you can safely infuse and be sure of a thorough wet out?

The boat must be light and stiff and I intend to use some fabrics that I already have. On the hull (which is extremely flat from side to side and minimal curvature from bow to stern) I was thinking of Alufibre (primarily cosmetic as light colours don't show scratches as much), then diolen, glass, soric, kevlar, kevlar,

so, Hull...    inside layer- kevlar,

                                     kevlar,

                                     soric,

                                     glass,

                                     diolen,

                outside layer- Alufibre

and, Deck...  inside layer- kevlar,

                                      kevlar,

                                      soric,

                                      diolen,

                 outside layer- carbon fibre

The deck is a very simple compound curved shape, so naturally strong and not as subject to abrasion/impact, but more visible,

Any thoughts or concerns?

Donnacha.