Has Confer wrote:

I am wondering how you get the metal to stick to composite, perhaps you can
put a conductor in the final coat?  I suppose you could coat the entire prop
too...

Hans Conser

Epoxy bond to most metals is in the range of 2000 to 3000 psi.
If the metal is thin enough the weight is low. If the weight is
low the centrifugal force is low enough so the metal leading edge
stays on. 

For an example 0.016 aluminum  one inch wide and ten inches long 
at an Al density of .1 pound per cubic inch would weigh only  .016
pound. The area is 10 square inches so the bond force at 2000 psi
is 20,000 pounds. IMHO more than enough to hold the metal weighing
only 0.016 pounds. The formula for centrifugal force is mV^2/r

r = 3 feet V = about 1000 feet per second at the tip.
m is 0.016/32 or about .0053 slugs so the load on the metal
worst case is about 2000 pounds if my math is right.
Worst case assumes all the metal is located at the tip
which of course is not the case. It is way better than this.

Yes if you electro formed a metal skin for the prop I am sure it 
would stay bonded on if the thickness was kept low. You might even
be able to electro plate a carbon fiber blade as it is already 
conductive. Actually there is a process for chroming plastics
as one see this all the time in cheap products.

Paul Lamar
 
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