I am just getting into electric, and am having clearance problems with the recomended APC 12x6e. My thought is to get a 4 bladed prop for better ground clearance. I know that twice the blades does not equate to half the diameter. My question is; does it equate to half the swept area?

I take the sqaure of the radius of the 12" prop (36''), divide by two to get 18'' and take the square root which gives me about 4 1/4''. Rounding up to acount for the loss of efficiency, I get 9'' diameter.

There is enough thread on my drive shaft to ''gang up'' a couple of 9" APC's. Is this a valid method for aproximating the 4-blade equivalent for a recomended 2-blade? Does APC make 4-blade e-props? (If so, my LHS does not carry them)