Need to fill gap between fibreglass arches and body

[ems]

I've just got a car that has fibreglass arches bonded to the body. There's a gap between the arches and body that's large enough to fit my hand into, what's the best way to fill the gap? It will also need to be waterproof.

Any suggestions?

 

[norsa]

Can't picture what needs filling if they are bonded already. Got any pics?

 

[shed or dead]

If it's as I'm imagining, filling will add unnecessary weight. Perhaps best to bridge the gap using wire mesh, then fibreglass over that. If you needed to wax-oyl inside, remember to make a hole in the mesh before glassing over. You can always seal the hole after injecting the wax.

 

[ems]

Thanks for the reply, bridging with mesh and fibreglass looks like the way to go.