: I am sanding the hull on my Gilly after several fill coats and
: still have a fair amount of shinny spots that look to deep to
: sand out. I so far have been sanding with 120 paper and
: wondering if this needs to be sanded to 220 or more to get the
: best clearity. I than think i may put a final coat of thinned
: out resin to help fill the shinners but just like the varnish
: the stuff does not stick well to the shinny spots. Should i use
: a different type of sander for this maybe a Scotch brite pad or
: something. Nick said he uses a little bit of cabosil in the last
: resin coat to help with the fish eyes. I will try this because
: they have allways giving me problems in the final varnishing
: stage. Any thought on this pro or con. Thanks Joe
A few thoughts:
If you want a glassy smooth final finish, you need to sand (or sand/fill/sand/fill/sand...) until the surface is uniformly 'dull', before varnishing.
I like to use fairly coarse wet paper (120?) for this, and then perhaps move up a few grits finer before varnishing. If you are power sanding, be careful about small 'lumps' sticking to the paper and causing deep swirls/scratches which will show through the varnish.

Try to find a not-very-visible spot to 'test sand' to see how far you can go before you are cutting into the glass.

Actually, I'm not all that fond of the very glassy look ('inch of plastic' look) on wood boats, so the very minimum finish thickness that will do the job is my goal. (Weight and $$.....)
Be careful thinning epoxy, as too much solvent will result in a 'rubbery' result.
Warming the epoxy (before mixing and application) will make it less viscous- just get it on the boat quickly, as warmed epoxy will cure faster than usual in the mixing container.
If you are having adhesion problems with epoxy (or varnish on epoxy), my first guess would be amine blush.
Give your boat a good wash with water and a scotchbrite pad. If you use a bit of detergent (I do) be sure to rinse well. (Wash before sanding, usually. Dry sanding can just spread that greasy blush film around.)

As I recall, Nick's use of cabosil was to help in filling the weave of the cloth, not fish eyes. Fish eyes are usually from a contamination problem, I think.

John