|
Zinc problem Volvo Sail Drive
No - nothing else is corroding. The bronze sea-cocks are all healthy - they
are painted over and the diver checks them every 2 months - whenever the 3 small prop zincs are replaced. After reading all the very helpful responses to my initial post I am now leaning towards the theory that the prop is somehow electrically isolated from the engine block (and the large zinc)- as unlikely as that seems. However, I won't know until the next haul-out when it can be checked with a meter. BTW the large zinc had some sea growth on the surface at the last dive inspection - so it is not protecting anything... "Ernest Scribbler" wrote in message ... "claus" wrote The (folding) prop on our boat is made of Bronze. Are you trying to protect the prop or are you trying to protect something else from being corroded by the prop? Bronze is way up on the cathodic end of the galvanic scale, meaning it *should* corrode zinc fairly rapidly. And of course it will also corrode other anodic metals like aluminum or iron if there's no zinc handy. What other metals are involved? Is there a problem other than the prop zincs eroding? |
Zinc problem Volvo Sail Drive
"claus" wrote in
: After reading all the very helpful responses to my initial post I am now leaning towards the theory that the prop is somehow electrically isolated from the engine block (and the large zinc)- as unlikely as that seems. However, I won't know until the next haul-out when it can be checked with a meter. All it needs is a rubber damper to isolate it, electrically...... -- There's amazing intelligence in the Universe. You can tell because none of them ever called Earth. |
Zinc problem Volvo Sail Drive
"claus" wrote
I am now leaning towards the theory that the prop is somehow electrically isolated from the engine block (and the large zinc)- That may well be the case, but it's not necessarily a bad thing. If you haven't done so already, you might want to try to find out if it's that way by design. Perhaps frequent relpacement of prop zincs is the price of admission for your particular unit? There generally are no easy solutions to galvanic corrosion, only trade-offs. For example, if you electrically connect your prop to your drive unit, you might be encouraging its galvanic currents to attack a nearby aluminum housing rather than a more distant sacrificial anode. |
All times are GMT +1. The time now is 04:30 AM. |
|
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 BoatBanter.com