I've never had to bother with vibration with my electric systems but I'm getting a lot of air bubbles in the fuel line in one of my nitro birds. I'm hoping that I don't need to use the foam clunk that I've just bought because I've also bought a prop balancer and can see that one blade on the APC prop is definitely heaver than the other. I've read that you can sand some prop away, paint on some varnish, or even stick a little bit of tape to the prop. Surely sanding can only weaken the prop or change the geometry. I'd prefer the latter. Would this be ok ? Also, is it true that the prop is balanced if it stays settled in any position apart from when the blade is resting on the bench ?