Here is my process. Just finished doing this for my Meister P-47.

I mix the amount I need right on the scale, adding a couple ounces for what sticks to the container. This time, I used 20min epoxy, because i was mixing over a pound of ballast. This gives you plenty of time to mix it well. Then simply pour it in and work it around where you want it. It is very heavy, very easy, adds strength to whatever you put it on, will never come loose, and is completely safe.