Block Sanding a Porsche 911

Looking down the side of a car, and not seeing a ripple in the paint, is such a great reward after countless hours of body work.  There are a lot of different factors to getting there, but some block sanding techniques are towards the top of the list.  

The video below is a clip of block sanding with 220 grit.  There are several things to note while watching:

  • The Sanding block. It’s not excessively big, but it’s long enough to span a good portion of the panels at a time. It’s a 22”  block from all of the True Blox sets, and it’s pretty rigid. 
  • The pressure.  The block is doing to work, and not being forced to sand anything. I’m using just enough pressure to hold the block against the panel. 
  • The angle. For the most part, the block is parallel with the shape of the panel up and down. But, it is almost always at just a slight angle.  This helps keep the panel be ‘straight’ up and down. If it’s totally parallel, it can more easily just follow the highs and lows vertically in the panel. 
  • The direction. You’ll notice I’m not blocking in each direction a completely equal amount of times.  This is on purpose. This is because you need to be paying close attention to how the panel is blocking, and how the panel feels through the block.  Since True Blox are hard blocks, you will feel feedback from the panel of if it’s smooth or choppy. Pay attention to this and always try to block against the way it needs to be sanded in order to flatten everything out.   The key to this is paying very close attention to what’s going on, and not just going through the motions. 
  • Yes, there are some slight low areas that show up in 220 grit.  This entire side appeared perfect in 100 grit.  This is the importance of 220 grit; to get it really dialed in.  In the case of this, keep working on the door until it’s blended into the fender, and don’t force it or cheat with another block. 
  • The sandpaper is blue 3m stick-it paper, 220 grit. 

To see the True Blox sets, click on the menu (top right), click on Products, and then True Blox.

This car was restored by the incredibly talented team at Road Scholars.