How do I balance the rudder?

[Scott Alexander]

I am having the rudder repainted on my ASW-15B.

There is nothing in my manual about balancing the rudder.  Does anyone know any details or information on how much to balance the rudder?

Thanks,
Soctt

[Johan van Ravenzwaaij]

By my knowledge it's not necessary to balance your rudder.  Tip: don't forget to do a weight check after any paintjob.

[Chris Norman]

If you removed the paint on the rudder there would be no issue. If you are increasing the weight by adding paint then there may be. Obviously if every owner added paint then at some stage the mass balance would have insufficient mass to damp out flutter. If you check out mass balance of ailerons or elevators the principle and maths are exactly the same.

[Chris Norman]

I should have added "for a rudder".

[Chris Norman]

I case anyone reading this does not know what "flutter" is, it is when a control surface in response to some upsetting force starts to move about its hinge point in a divergent fashion. That is, normally a control surface fairs itself with the airflow. as the airflow speed over the surface increases it can reach a point when the control surface moves in the airflow and this in turn bends the wing it is attached to. and the condition increases until it stabalises or the wing comes off. Mass balance is a heavy weight that stops the control surface from fluttering, moving up and down quickly.
Go to utube and select "how to break a gliders wing" for a demonstration of flutter.
The reason that there is calculation required is so that the least weight possible is used to damp out the effect.