The second step of block sanding polyester primer is using 220 grit. This follows the ever important step one of 100 grit. Step one was to of course get the panel straight, but also to cut the texture out of the polyester primer.
220 grit is equally as important, and a lot of attention needs to be paid to everything that is happening. All the finer details will show up in this step. It is crucial to watch exactly how the blocks are sanding, and that they are sanding evenly. This step is still aggressive enough to fix some slight low areas. Don’t force the blocks, let them flex naturally and do their job and work their magic. This might mean picking a more flexible block.
Whats the point? Treat this step with very high importance, take your time, and pay very close attention. This is the step where you can really get your work dialed in, and take it to the next level.