When to Switch Grits

When body working a whole car, it’s important to use the correct grits, and know when to switch to the next grit.
♦️40 grit should be used to barely rough the general shape into the filler. The panel does not need to be straight in 40 grit. Typically, 40 grit is used before the filler is completely dry so that it’s easier to shape.
♦️80 grit is used to finish getting the filler straight. Once the panel is straight, you do not want any left over 40 grit scratches, which is why it’s important to not over sand with 40. The bulk of the block sanding will be done with 80 grit.
♦️Once the body work is straight, switch to 120 or 150 grit. This will fine tune the filler a little more, and more importantly, is a far better grit to spray polyester primer over.

♦️♦️A big thing to remember is that the body work doesn’t have to be straight to stop with 40 grit, just barely rough the shape in with it.