Well, for many years I have been "candling" my sanding by using the shop lights. Today for some reason I went outside into the very bright fall sun and candled a stab. WOW, do I need to do much more sanding. Looked great under the shop lights, but under the sun, not so much. Yesterday it was a cold, miserable, windy, heavy rain, day, Today, calm, warm and sunny, so I took advantage of the sun. Good thing. There was a long narrow groove in the bottom of the stab (this is for an Evolution 40), so I made many tiny pin holes, filled them with water and let it sit. Two hours later no groove. The balsa swelled right up and up lifted the groove. Be careful what your lay parts on.
It now sits with a third coat of non shrinking dope.