Randy
I must have spent too much of my life varnishing.

: 1. Can I varnish again over them at this "smooth sanded" time or should
: I sand down to glass pattern, reepoxy, resand and then varnish?

Any area that's not worn through the resin can be revarnished after a light sanding to get the new varnish to adhere, I like to wet sand with 200-400 paper so a minimum of the old surface is removed. If the old varnish has started to peel or lift you'll have to remove it to the resin surface. Name your poison, sandpaper, scrapers or chemicals. If the glass pattern is showing and the glass has not lifted or been torn from the surface, you should sand it and apply mor resin before varnishing.

: 2. My "Captains" varnish has a 1/8" hard skim on top of it after setting a
: year. Can I use the liquid varnish underneath as is or should it be thinned?
: The first time I usd it right out of the can and it worked fine.

I'd cut it about 10-20% with mineral spirits. I find that decent quality varishes are too viscous from the can. This makes them hold air bubbles that end up in the finish. Your varish will now be thicker than it was when you last used it. A cheaper varnish usually has fewer solids and doesn't need thinning. You're trying for that happy medium where the varnish doesn't run on vertical surfaces, but doesn't hold air. You can't avoid some bubbles, the trick is for the varnish to let'em go before it cures. To cut down on bubbles never dip your bush in the original can, don't return decanted varnish to the original container and never wipe your brush on the container lip to remove excess varnish from the brush. All these practices will mix air into the varnish. Be careful removing the skin so you don't pollute your can. You may want to just slit it so you can pour out the varnish you want to use. To avoid varnish build up in the can's top sealing rim, take a thin finishing nail and punch 3 or 4 evenly spaced holes in the depressed part of the rim to allow the varnish to drain back into the can. You'll find the top will seal a lot better and thus help preserve the contents. Don't light up when opening a can you've preserved with propane unless you want to get rid of your John Lewis like eyebrows!

When using propane I alway mount a small spark plug in my can tops so they can be easily removed with a little electricity. Of course, my shop has a high ceiling )8-0.

: 3. If I want to put another layer of glass over the places that get the most
: abuse, can I do it right after my complete sanding which takes all the
: gloss off the present hull? Any unusual prep different from the initial
: building?

You have to be sure to get all the varnish off and any amine blush that may be left from building. Use 80-100 grit to strip and prep the surface . Try not to cut into the glass. Then wash (the hull, your personal hygiene is none of my business) with soap and water

Geo. C.