Is anyone using corn starch or other powder to track flow separation?

Combatpigg, your comment is well taken. By spraying a water based paint on the spinner and prop we discovered the gap problem right away and filled it. The prop was able to draw more current through the motor with these changes.

The problem with this testing is that none of us have a lot of spare time to devote to all this. I would like to figure out a way to scratch build composite wings and fuselages. The ARF kits are really expensive especially if you're going to hack it up anyhow. The best thing we have is that we want a fun plane not a strict by the rules plan like an F5B pylon racer. I just want to lean how to fly better and have some fun and experiment along the way.