I have a table top I wish to varnish over and have bought some Ronseal
Diamond Hard Clear Satin (water based) Varnish.

I would like to get it on as *smoothly* as possible and not being too
brilliant wielding a paint brush wonder if, since it is a water based paint,
i could *dilute* it right down with boiled water and then more or less
'smear' it on using a rag, then turn up the central heating and hope that it
would all dry very smooth?

Another thought I had was to use a small roller. Our local store sells two
types of rollar surface, a sponge for gloss paint and a hairy one for
emulsion. If using a roller was a possibilty to get a very smooth surface,
which type of roller surface should I buy please?

Thanks for any advice with this.