Brilliant thanks.

I get my 3000 from my local paint supply place in Swindon

LOL, Might be fun to watch though.

I had a look on interweb for finer grades but best I could find was 800. Where do you get yours from?

The finer grades have to be wet. Not sure id try it with an electric one but air ones are fine 

wet or dry?

They work fine on anything, I have 3000 grit I go up to before polishing

Can you use an air DA sander for fine sanding and wet sanding? I already have an electric DA sander but I thought it was only useful for grits of 120 or 240.

If you're getting a spray gun, I guess you already have a compressor, in which case I'd seriously recommend getting a DA sander and a few tubs of different grade discs, the amount of time and effort they save is worth the £50-60 outlay

Thanks guys
I will give the sponge a try while waiting for the spray gun.

I have successfully used fine-pored household sponges to apply PVA. These sponges are white and a little harder than the kind of sponges you use in your kitchen sink. Put some PVA solution onto the sponge and wipe it onto the mold. Just once, don't play around with it while the PVA dries. The PVA self levels and produces a uniform film thickness. Beginners usually overestimate the amount of PVA required, only a very thin layer is required.