Cheers for the advice Warren
My  Uni-Mould kit just arrived no problem.
One small difficulty is that the resin has arrived in one 25Kg tub, and I will only be mixing 1 kg at a time.
Any advice on how I can get small quantities into small pots easily - I can't really pour from the 25kg tub to a pint glass without spilling it all.
Also, could you offer the option of one big tub, or (5?) smaller tubs in the ordering process perhaps. It would help us DiYers a lot
Dom

The quantities in the kits have been sized to ensure the coverage is that figure, however 0.2sqm is not a lot extra.  Due to pack sizes, you have enough gelcoat and coupling coat to do it no problem, but you would need some more Tooling resin and CSM to be on the safe side.

If you are using extra wood formers after the main mould making to add stiffness, then no need for extra thickness. You can add the extra support using the wood.

I don't see why a silicone former wouldn't work.  You would get resin flash all around it as its unlikely to be perfectly sealed, but it would do the job of preventing the resin filling the voids.  Just take care to ensure its presence doesn't lead to any bridging of the fabric or bagging stack.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Carbon punt update - June 2019
Well, I have finally got some time and space to put together the mould for the hull.
I am constructing the plug in plywood, which will then be coated in perspex.
Some questions for you all:
1. I am going to use the Uni-Mould kit to cast the mould off the plug. Is the 3.3sqm a maximum area this will cope with, or might it be streched to 3.5sqm?
2. What thickness should I make the mould (considering that the plug is 4m x 0.6m x 0.25m)?
3. Can I use wooden slats in the mould to strengthen it, and bind these in with resin?
4. I will be infusing the hull, and need to put some intricate parts in at the same time. I was thinking of placing a silicone former over these to stop the voids from being filled with resin - has anyone had any experience of this?
My website should be updated soon as well
Thanks in advance