I'm using the porter to apply Sonus Paintwork Cleanser...what should I set the porter after I start out at 1 or 2. Should I go up to 6 or stay around 4. Sorry, I tried a search, but I'm in the process and need a quick answer.

 

You won't need a ton of friction to break down the abrasives in Sonus PWC, since they're so fine. I'd work it in at speed 3, and as soon as it's worked in kick it to 5 or 6 with almost no pressure until it dusts or goes clear, then wipe off. Remember, a little goes a long way.

 

I agree w/ Picus on this... I usually stay between 4-5 I rarely ever go over 5 unless I am stripping or preping to re-paint on area.