I have a part from which I want to take a mould - it's around 50cm long by 46cm wide at the widest point.  I'm unsure as to whether the ready mixed epoxy fibre kit would be best or the uni mould kit, and which size to use if the former.  Guidance on this would be great.

It's a small motorcycle fairing and is curved so part of it touches the board and the top is about 6 inches of the board.  I've watched the video and saw that when making a small part, modelling clay is used to created flanges. I could do that with the part it would just need a fair amount of it (46cm across by about 15cm high) to bring the moulding cloth/putty down to the board. Is that the best thing to do? Or better to cut out sign board and make flanges that way? 

Hi Mikew,

Epoxy gelcoat and its putty is fine, I used it with with sucess in the past for small parts.

But if it was for me, i would use UniMold method. It's more like regular mold making method, gelcoat then layers of csm. Resins are filled to keep mold from retracting too much. Thickness of the mold will be more uniform (compared to the epoxy+putty), leading to less uneven distortion during cure. Plus you can even post cure it to a higher degree than the epoxy one (90°C for the Unimold and about 60°C for the epoxy if I remember well). Maybe not necessary, but you can if you ever want to try.

For the flanges i would use signboard. Signboard will conform better to your part and then u'll need less fileting wax, as opposed to laying your part on a flat sheet and fill enormous gaps. Do NOT hesitate to make flanges bigger than what you think you will need. Better cut flanges afterwards rather than having the joy to discover than you made them too "thin". I usually make 'em about 5 inches wide. It may appear as a waste of material, but I'm always comfortable with laying cloth and consumables. In some occasions, it leaves the stress out of the room

Hope it helps, good luck in your project.

 



 


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