Re: ANODE ?
If I may offer a bit more detail....Outdrives are made of dissimilar metals - mostly aluminum & stainless steel. When you put dissimilar metals in a conductive solution (i.e. water), you are setting up a galvanic reaction. Electrons will flow from the less noble (aluminum - negative - anode) to the more noble (stainless - positive - cathode) same as in a battery. After time, the anode will lose enough electrons & oxidize (corrode). Sacrificial anodes on an outdrive - bare, unpainted zinc or magnesium or aluminum depending on the application - are designed to corrode before the painted, protected aluminum of the outdrive housing. In the absence of such sacrificial anodes, the outdrive WILL corrode - regardless of how well it is painted or otherwise coated. If using a SS prop & keeping it in the water, additional electronic protection is required (Mercathode system, for example). Hope this helps you understand a bit.
