Fletching tape works great over gasket laquer.
I have used gasket laquer on lots off arrows, some of which are three years old now, and have never had any cracking or water resistance problems. Have never had any feathers come loose either and that includes pasthru's on haybales, grouse, deer, etc.
I keep my dipping tube indoors at normal room temperature. Now that I have a house with a garage I have kept it outside but have not yet used it since doing so. After reading dhaversticks post I think I will bring it back inside before building anymore arrows.
My two cents