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On Thu, 23 Jun 2005 11:35:03 GMT, (~Roy~) wrote:

I had been in the prop repair business with my dad up until a few
years back, and if done properly they willl work as good as a new prop
or better. It is not something that can be done without the proper
pitch blocks. Other than flat filing any raised burrs off do not grind
or file on the outer edges of the blade or attempt to thin an edge
out. Its just as important to have equal surface area on each blade as
it is to have them all the same pitch. You grind off the edge to
remove nicks you'll only have to pay to have it built back up again if
yu go the repair route.

NIcks etc on the leading edges of the prop will cause or induce
cavitation, which may or may not affect performance but over time it
will cause erosion of the blades at the root/hub section.

Rebuild should run between $25-50 bucks depending on type prop and
amount of damage........hubs generally run $20 to 60 depending on the
prop.....if your payaing more than that your getting shafted.....

A lot of repair stations use the zinc filler rod and the O/A to fill
in nicks and missing pieces........This may last for some time but you
will find it is very prone to breaking out, and a shop that TIG welds
it up is the best route and it does not cost anymore overall.......

While shops maya play the balance deal on props it is highly unlikely
that any shops balance most props other than the solid bore props and
even then its unlikely...............Foks assume its out of balance
due to vibrations but its usually always because it has one or more
blades out of pitch that causes the vibrations. You can take a new
wheel and check it for balance, and you would be surprised just how
far out they are. Even in prop repair school, taught by Merc and back
them OMC and Rundquist Prop Tools, they told us straight up, don;t
waste time balancing these props......A prop run in water is different
than a prop run in air, and variation in weight and balance will not
have any effect on it, however its a marketing source for an extra
buck for doing nothing to earn it. Only props I ever balanced were the
typical bronzes found on ski natiques etc, again a non hubbed, ridgid
bore prop.......never a rubber hubbed prop.

If blade shapes, surface area and pitch are the same and if its
ground to carry the overall blade thickness on the repair to follow
what ws original, it will be fine.

A prop actually only uses the outer 10% of its blade to do the
work......the inner portion of the blade is needed to hold on the
outer portion and does come into play at low or intermediate speeds,
but most work is done by the outer 10% of the blade itself. This is
why nicks and dings on the blades tips are important to have repaired.
Your one blade tip looks pretty chewed up to me and I would be
surprised if that blade itself was not also bent out of original pitch
shape......so it really needs to be put on a pitch block and checked,
repaired, and not merely file off the nicks etc......

Every once in a while, a real gem comes along.

Great information - thanks. I always thought balancing was a part of
the repair process - now I know.

Appreciate it.