Making it Smooth and Shiny
Next you cover it up with Saran (or other) plastic wrap and use some tape to stretch it smooth.  Kind of like stretching a high-tec beaver hide.  Squeeze out the air bubbles under the plastic with your now ungloved thumb.  Work the air bubbles to the edge of the resin under the plastic.  Try not to squeeze the black goo down the sides of the canoe.  After you are done with the air bubbles, flip the and rightside up and not on the new resin and allow it to cure for about 5 hours.  After 5 hours, flip it back over and peel off the plastic.  Take a sharp knife and you can carefully slice off the excess resin which may have run. 
 

Skid plate is done - on to varnish

Appling Varnish
You can now sand down the canoe with 120 grit sand paper to somewhat smooth out the scratches. An orbital sander works best. You should wear a dust mask for this because it gets dusty.  Then wipe down the canoe with a brushing thinner and follow it immediately with a good quality UV blocking,  marine varnish by either wiping it on with a rag or with a foam roller.   The rag will initially do a nicer job.  Wear disposable rubber gloves and  clean up will be a snap.  Allow it to dry two or more days then sand down with 200 grit sand paper, wipe down with thinner and recoat the canoe either with a foam roller or rag.  I prefer the foam roller here because it's a bit easier to control a uniform coat.  If you do use a foam roller, once the canoe is coated in varnish, grab the roll to prevent it's rolling and drag it uniformly over the canoe (called tipping) to knock out the little air bubbles that the roller leaves.  Allow canoe to cure for two days and then paddle with abandon or even a friend or family member!