I do 3 cc mix at a time. The more you make the more room for error. But try to be rt on the mark.
I have been using a rotor motor for years now and they work great. I epoxy in the basement with a heater on and go for about 4 to 5 hours. I have enclosed a section of the basement in platsic you no like the boy in the bubble

. But if reel cold I do it on the kitchen table ( my wife love this

)
Macojoe