Re: Corrosive attack at the propeller - Pro Series
Hi,<br />Is the prop also down in the water when the boat is not used?<br />Or do You have it tilted up out of the water?<br /><br />Seems there is a galvanic corrosion going on. Have You checked that the anode(s) on the outboard has contact with the aluminuim? It should not be any paint betwen the anode(s) and aluminium on the outboard, the paint will prevent "contact" and the anode will not be "sacrificed" as intended then. And no paint on the anode(s).<br /><br />I have a Yamarin boats myself (5820) and Yamaha F115 4-stroke but it is used in freshwater. I use a Yamaha black steel prop. I have no problem with corrosion on the prop. I have the outboard tilted up out of the water when not in use.<br /><br />What did the Yamarin/Yamaha dealer say when You had to change prop the first time? Did they investigate anyting at all why this happened to Your prop?<br /><br />If it is a galvanic problem it is like a battery, two different metals in a fluid, electrolyte, like salt water will start a current and one of the metals (or both),the "anode", will start to corrode (dissappear) bit by bit.<br />Seems that Your prop is an "anode" for the moment and gets corroded.<br />Maybe You should have a marine electrician (paid by the Yamarin/Yamaha dealer of course since Your boat and outboard is still under factory warranty) have a look at Your outboard, electrical installation and the "anode" problem.<br /><br />Is it anti-corrosion grease applied to the prop shaft?<br /><br />Here is an article (in Swedish) that give some information about galvanic corrosion in boats:<br />
http://www.vibatagare.com/artiklar_vib/varrustning/varrustning2.html <br /><br />Another article about this subject:<br />
http://www.boatus.com/boattech/MarineCorrosion.htm <br /><br />Just search Google for "galvanic corrosion" and You will get plenty to read.<br /><br />Good luck!
