8. No matter which welder is used, you will need to grind the area smooth. This is where you need to take your time; if you get too aggressive with the grinder and remove too much of the bumper material it'll take more time to fix it-and we all know time equals money. When you're done, you should see something like this. The weld and the factory chrome are grinded down to the base metal, but that is it. Anymore grinding and we'd start removing the base metal, and once chromed it would look wavy.