Blog Brief: Sanding out a run

When spraying a car, especially the clear coat, runs--formally known as 'flow indicators,'--are inevitable.  Because I was hosing my clear on and also had some inadequate lighting on one side of the car, I had my share of runs to work out...some that ran along the entire length of the body lines on the door and fender!

There are a number of ways one can sand out a run: scraping with a utility knife blade, putting tape over the run and sanding the tape, taking a tiny block and trying to sand the run and only the run, or--my preferred way (and the way I'll describe here)--skimming the run with glazing putty and wet sanding.

The goal in sanding down a run is to protect the surrounding clear so the run and only the run is being sanded.  Skimming the run with glazing putty protects the surrounding area so only the run is being sanded.

Here on the passenger side I have skimmed a coat of glazing putty, such as Evercoat Easy Sand.   The thinner the coat the better as it will be less sanding effort to sand it off.

Start WET sanding with 320 on a HARD block.  I cut about an inch length of paint stick and this was a tiny block I used.  I also used a short piece of 1/2" PVC pipe or a wooden dowel for round blocks.  You can see exactly where the run is and how the high parts of the run only are getting sanded down.

Continued sanding and the run is 90% removed.  After a little more of the putty is removed, then switch to 1000 grit wet and finish sanding the run and remaining putty.