Making a prepreg carbon front clip for my Lotus Elan. So far so good.



Mould with the reinforcement that caused the problem. I bagged the whole thing. This resulted in a differential pressure between the inner surface and the outer skin under the reinforcement which resulted in the mould sinking under the pressure!

Correct resin, gel and fibreglass.

The central part is black as I ran out of fibreglass :-)

Agreed, the ribs were not necessary, hindsight is a wonderful thing :-)

Total of 8 layers  with 6 under the reinforcement and two on top.

Drawing below shows the construction and deformation cause, which was a combination of pressure differential and lack of post cure IMO. Without the reinforcement the lack of post cure wouldn't have been an issue. If I had post cured I might have gotten away with it.

If I had just bagged the underside the pressure would have been constant on the other side and the deformation wouldn't have happened. Oh, well, hopefully I can rescue the bonnet.