Originally Posted by Guy
foggysail; Could you elaborate on this aluminum anode idea? Why does everyone use Zink?
Sure! Before I start, aluminum IMHO is the best kept secret for anodes. But an aluminum anode is more than just a chunk of aluminum. It should be made to the Navy's MilSpec Mil-A-24799. I have used them for years and only one at that on my 40' Silverton. Mine attaches to the stern....in the water
of course...and is sufficient to provide all the protection needed from galvanic corrosion
Everything you need to know is described in detail at
And best of all, aluminum anodes not only will last longer, they cost about 1/2 that of zinc. The 1st attached URL gives so many more details on anodes, I recommend you go there to read the benefits.
Most guys who use zincs on shafts know from experience that they never seem to last long. There is also a poor electrical
bond between the the zinc and the shaft. I HIGHLY RECOMMEND using shaft brushes to bond the shaft/prop to your boat's bonding. I have not looked for the commercial
brushes although some have said they purchased a pair for under $100.
My first experiment
with my brushes used bronze plates taht I silver soldered to brass bars that rested on the SS shafts. The bars/plates were made common with my boats bonding. That experiment
was a failure. One short trip out almost destroyed the bronze that rested on the shafts. I had bronze dust all over the place. I solved
that by using oilite (sintered bronze bearings) pieces that I bolted to the brass bars.