the paint is your main problem id say on zook steel as in panels about 15-20 psi but as i said im no pro! but the best way to learn is to jump right in (i think) sand a small area back to bare metal and put your earth clamp on that then sand where you want to cut. if your cutting a piece that isnt the best ive learnt to use a small hand smooth half round file to keep the tip nice and clean and use the edge to clean out the cross grooves.also if you are cutting out car panels ive learned the hard way not to cut through the braized joins with thongs on
