Yeah, guilty of number 2.  I used a 200g layer for a pretty finish then 2x600g layers to make it nice and rigid.  Other than that I've been good.  All carbon, EL2 resin, under vac for 24h etc etc.  Luckily it wasn't too much movement and I've recovered it.  I'll get some final pics in the gallery at some point but here it is.  This is trimmed and cleaned.  Its a side scoop for a VX220 air intake.

Hi,

• Dissimilar materials - e.g. backing carbon with glass, this often creates a very noticable distortion especially when cured above ambient. it creates internal stresses in the part that in turn 'pull' it around.
  
• Imbalanced laminate - e.g. 1 ply 200g, 1ply 650, 2plys 200g , every weight and style of fibre performs differently even when it's all the same fibre type (e.g. carbon) this will have a similar effect to using dissimilar materials but less pronounced.
  
• Not using epoxy resin - resins such as polyester shrink alot more than epoxies and will 'pull' the part poor quality epoxies can do the same thing.
  
• Uneven curing - if the part is not cured evenly (commonly caused by uneven heating) this too will tend to distort the part
  
• Fibre orientation - rarely causes distortion but aim to keep a balance where possible

Guilty of any of the above? if so address that, if not we'll keep hunting until we find the problem!

Paul Statham
Easy Composites / Carbon Mods - Technical

I've made some parts that were under vacuum and cured for 24h.  They were then post cured in the moulds for 8 hours at 60 deg C.  I've pulled them, trimmed them and lacquered them and I've found a slight movement in the moulding.  Its a scoop and its 'opened out on its edges.  Any ideas whats caused it and how I can stop it?  I can flex the moulding back to how it should be to bond the grilles in (about 4-5mm out)  but I'd like to be able to stop it in the future.