Albert,
We have done quite a bit of research on this topic
and it seems most agree that a rougher surface is better.
I use a cretex wheel between 24 and 60 grit on mine.
I think on our set ups you will find that pitch,cup,and
diameter have a lot more to do with the performance of
our propellers. I can tell you there is no perfect finish on
our propellers that we have ran across yet. I can tell you that
we are looking at several finishes like the big propeller guys use.
Mercury Racing CNC finish, Hering Propellers, Lab finishes are
a challenge because our blades are a little smaller. Once you rough
up the face of the propeller surface with a cretex wheel or abrasive disc
you will not see much difference on the speed of the boat. The cavitation
with a smooth finish will be more pronounced with a polished face that is for sure.
We have tested many different finishes with my Stalker Pro and have found no
speed changes with identical propellers. I would encourage others to go to the
pond and test your best finishes and let us know what you found? FYI, You are going
to need a Stalker or better to see a little change in different surface preparations.
Have Fun Testing And Racing Fellas,
Mark Sholund
231.590.3023