Knowing which brush to use when can be confusing and sometimes controversial. I have five brushes in my wax box. Two that are used for pure 100% fluorocarbon waxes, and three that are used for the rest of the waxes in the Cera System.
The two used for the pure fluorocarbons are the: Black Nylon Brush used to brush out the wax and the Blue Nylon Brush to polish. It very important to have dedicated brushes for these waxes, to ensure they are not contaminated with other waxes.
For all other waxes in the Cera System I use the: Fine Steel Brush for the colder to mid range waxes 4, 6, & 7, the Medium Bronze Brush for warmer waxes 8 & 10, and the Blue Nylon Brush to polish.