Hmmm, you're a fair way from me I'm afraid.  Best of luck with the fix though. 

Thats super i love learning about this stuff , im in kent but dont worry the chances of me getting in the garage are nil with a 1 yr old so just collecting info for time being 

No worries.  Polyester is often tinted blue.  Some resins have an indicator in them.... blue - good to go, green - times getting on, brown - get on with it gel time is approaching!  Obviously if you tint it you wont get this.

Epoxy does have a stronger bond but is harder to use with CSM.  I've done one or two crash box repairs and always used polyester.  It works just fine.

Whereabouts are you?  I'm happy to help if you're local to me.

Wow , thank you for that .  Did find a picture of a guy using a blue tinted resin which i assumed to be polyester but reading the net everybody seems to say epoxy is far better but think I'm getting muddled up between carbon and GRP now  , still thanks again for the advice

The elise crashbox can be repaired with polyester (pigment it black so it looks right).  As you say its ok as long as its just the lip.  You shouldn't really need to cut part out of a second one to repair the lip though, it'll be easier without.

The OEM moulding is a closed mould process with high tensile nylon down the crush tubes, CSM all over and a woven infusion mesh covering the whole lot.  I've seen some horrible bubbles down the crush tubes where its not moulded correctly.

Hi all , new to all this but since i've got a plastic car that needs repairing thought i would join up to tap into the knowledge on here .

 My question is what resin to use to join the front edge of the crash box , it looks like carbon but googling shows its GRP, i have the part cut out of another one just wondering what resin would be best to join them and then would a carbon tape help to strengthen the join .

 if it was huge damage i would replace the whole thing but the tech manual says repairs to the lip is ok

Cheers