During a class i took on composite aircraft repair (full size planes) I was told to always let resins sit for a few minutes to let the bubbles come to the top. We always used slow curing resins so you had the time to do so, you dont have enough time with 6 or really even 15 minute epoxy. For me, if anything is important enough to worry about bubbles, i am going to be using 30 minute or slower epoxy anyway, so i just let it un-bubble itself.