Ive managed to crack one of my rear wings - the edge has had to be glued back on however i am left with a nasty crack line and a couple of chips that require filling. I have some P40 filler which hopefully should do the job however am not sure what grade wet n dry to use? I couple of searches on here have suggested 600 grit however somebody has mentioned 2000 grit. Is it just a case of working my way up in 'grit' levels to get a smooth finish?

Also how easy is it to blend the new paintwork into the old paintwork? or will it just be the case of sanding the whole wing down and respraying the lot? They are currently black.

All tips welcome!

[Edited on 24/6/11 by joemotion]

I use 80 t0 rough the filler down then 120, 240, 400 if you want to go finer. That's plenty if you are priming over it then 600 and paint over the primer. Make sure it is well feathered into the old paint to avoid a line round it.

If its David P40 thats no good as a filler David p40 is a fiber glass mix
you need proper body filler
Jacko

cheers guys

any tips on blending the paint together?

IIRC the correct way of dealing with cracks in fibreglass is to drill each end of the crack to stop the crack spreading followed by scoring a groove into the crack to allow filler to be inserted. If the crack has gone through the panel it's probably worth reinforcing from behind with a bit of matting