HI :
I'M BALANCING A CARBON FIBER PROP. WHEN IT IS ON THE BALANCER THE TOP BLADE GOES ALL THE WAY TO THE BOTTOM. I SANDED THE BOTTOM BLADE OVER AND OVER, AND OVER, FINALLY GOT IT TO GO 1/4 TURN FROM THE BOTTOM.
WHEN DO I STOP SANDING ????
DOES THE BOTTOM BLADE HAVE TO GO ALL THE WAY TO THE TOP AND THEN IT WILL BALANCE IN ANY POSITION ( NOT MOVE ).
THANKS------------BILL

I have been told that sanding a prop is a bad idea, so I always add CA to the light side and smear it with my finger (only on the back side). I have never had a CF prop, but I imagine that sanding too much could damage it. Is there any rason you could not add some CA varnish to the light side?

I will wait and see what some of the more experienced guys say. I would like to know too.

BTW Bill, please unlock the caps on your keyboard.

Good Luck,

Mark

I am FAR from experienced, however, I paint the tip of the blade with some fuel proof dope. I add additional coats as needed until it balances. It will not only balance the prop, but it provides a visual indicator so you "Don't feed the engine"

In my opinion, sanding the blade will weaken it.

Sanding a carbon fiber prop is not a good idea because....Carbon fiber is a composite material with specific properties that make it stronger. Sanding this type of material does 2 things:

1. It produces tiny scratches on the surface. These scratches create areas of stress concentration. This may cause the prop to fail unexpectedly and catastrophically.

2. If you sand too much, you will cut through the surface binder/resin that holds the carbon fibers together. This may cause the same results as #1. The exposed carbon fibers are microscopic and very sharp, like fiberglass except smaller. The fiber dust or splinters could easily become lodged in your skin, eyes or mucous membranes. You may need to see a doctor to have it removed.

In my opinion, to properly balance any prop, you should spray a light coat of poly-u on the front side of the light blade. This does not compromise the integrity of the prop or alter the basic airfoil shape.

Dr.1

Hi!
Of course you can sand any prop!!!! Just go ahead!
I sand my APC props ...even modify them by cutting filing and ofcourse ...sanding. I make my own carbonfiber props for pylon racing and scale ...which I naturally sand!
Always sand on the front side of the prop..the curved side pointing at you when you sit in front of the engine /airplane
So just go for it!

Regards!
Jan K

Don't bet on it, lillbill11

Dr.1