A milkshake is a mixture of body filler
. I try to make up about 10oz at a time. Usually about 7-8oz of body filler and 2-3oz of resin. Mixing
this can be a hassle! I use a drill with a whip on it in a small container. After I've done the preliminary mixing is when I add both the hardeners... Then whip again, and apply. This sets up very fast, so you have to work quite quickly! In the useful links, look up MilkShakes, and look in that thread for further discussion on other views on how to make these!
I like to apply my milkshake to the entire project, and cover ALL of the exposed fiberglass.