I have found when you get bubbles, it's because you dipped your arrows before all the oxygen bubbles have disipated from the canister.
How many times have you filled up a glass with water to quickly and it was cloudy, then in a few minutes, it's clear again? That's all the oxygen bubbles in the water making it cloudy.
Next time, fill your cannister slower, and find something to do for a few minutes while the air bubbles disappear.
Best advice I ever received about arrow building, was to not rush building arrows.