Hi everyone, first post on here.

This first thing I will say is that you will need a much bigger mould making kit. To make a mould of something like what you have got there, I'd estimate you will need around 1-2kg of tooling gelcoat (I always do 2 coats, but you can get away with 1 if you want to save a bit), 2kg of skin coat resin, and somewhere between 15-20kg of tooling resin. 

First off I would recommend you watch our video series on making a Carbon Fibre Bonnet as the principles work fine for all body panels. 

Especially relevant is the mould making side, including how you use the filleting wax and the flash tape to fill any unwanted holes and seal any edges from resin.  Also flange making is quite important.

Hanaldo is right on the mould making kit size. The kits are based on surface area, so once you have measured the full bumper moulding up (including the flanges you will make), that will give you a total surface area.  The large kit is 3.3sqm coverage and i suspect this is the ball park area you will end up in.

You need to view the bumper and aero add ons as one pattern if you are making it one piece.  How much preparation you do is up to you.  You could trim it and neaten it with filleting wax then mould directly off the sign board you have there.

However you need to bear in mind that the mould always is a reflection of the pattern, (and likewise the part a reflection of the mould) so any imperfections will be on the mould.

This isnt a problem if you use a thick layer of gelcoat, as you can sand the gelcoat smooth then polish it up again.

However, in most cases it can make sense to do all the preparation on the pattern first to get it to the highest standard ready for moulding.  You could use the signboard then filler it and use our Pattern Coat Primer and Gloss to get a final finish, or you could hand or CNC carve a foam pattern to go on the bumper and coat the foam with PCP and Gloss to get a good finish too.

The choice is yours really.

Be careful with rattle can spray paints as it can take a few weeks or longer for all the solvents to outgas and the solvents can break down release agents.  Proper spray gun 2 part paints are fine, or use dedicated pattern coatings.

Until you have finished the pattern, you won't know how much materials you need for the part. Once finished you can measure up to work out how much carbon you need per layer then come up with a layup schedule.  Something like 2 layers of material either side of the soric core should be plenty stiff enough. You might be able to get away with 1 layer either side of the core due to the curved shape adding stiffness.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant