I am getting my C4x4 bumper soon (shipped yesterday!) and I ordered it raw steel so I could paint it how I wanted. Originally, I was going to rattle can it for easy touch ups later, but ultimately decided on Monsta. I have used Raptor in the past (and liked it), but I chose to go with Monsta this round because of all the great things Ive heard here.
Anyway, since I am spraying it, I presume you thin it with MEK (as seen being done on YouTube by Eric) at a 1:16 ratio (I have a quart, so 2oz). Do I need to prime the bumper since it's raw steel to get Monsta to stick? When I did raptor, I just took off the clear coat, but the jeep was not raw metal.