"Gogarty" wrote in message

Put a donut zinc between the strut and the prop.

Uhhh, We HAVE had a zinc on the shaft and the MaxProp's hub as well.
Both get half eaten each year. Before the MaxProp & its zinc, we lost
the same half of the shaft zinc.

In article ,
"Boots" wrote:

why don't you treat the problem and not the cause???

We have no AC connection to dock power. There is no electrical
connection to the shaft or strut; the shaft is isolated by a plastic
drive-saver; electrical resistance between boat ground and shaft is
essentially infinite, so it's not from the battery.

It happened while we were in the mooring field.

Thus, I believe we solved what you believe is the problem already.

The *only* thing it can be is the difference in potential between bronze
and stainless steel.

OR... the potential difference between both steel & bronze and zinc, and
that's what I've been thinking for the past few years.

Truth be told, I *have* thought about switching out the shaft for
bronze. If the zinc still disappears, it's the zinc's problem as there's
nothing left. My only problem with this solution is that bronze bends
quite a bit easier than SS, and I'm more concerned about proper shaft
straightness and alignment than the loss of relatively cheap zincs.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/