So, should us aluminum hull types in fresh water be using the magnesium anodes instead of the zinc anodes? I checked a couple of marine catalogs and couldn't find the egg shaped ones for my prop shafts or the disc shaped ones for my trim tabs and rudders...any suggestions?
Art not Science Hmmm,..., magnesium - pretty volatile stuff. I use Sealloy strips made out of low-grade aluminum (available from Marinette Yachts - ask for John Althouse) on mine aluminum hull situated in fresh water. Work great. Start slow!
Cool! Will give that a shot. Thanks Eric, and I will try to get some pics on soooon...yea, yea, I know I've been saying that for months...(but fooling with pics on computers is winter work, isn't it?)
Aluminum is amphortoric and will corrode when it is under-protected and will corrode if over-protected. The use of magnesium anodes can lead to over protection. Mil-spec anodes zinc anodes are capable of protecting aluminum in fresh or salt water. The mil-spec zinc contains a half a percent of magnesium. The magnesium enures a burn rate on the zinc regardless of the demand to do work.
Mil-spec Most all of your store bought zincs are mil-spec with the exception of the ElectroGuard zincs. ElectroGuard zinc and Electro Guard corrosion control systems are not the same company. SeaShield, & Martyr manufacture zincs in all shapes sizes and mounting configurations. ElectroGuard corrosion control systems manufature a monitor only device that will greatly enhance your system. It is constant reading and will alert you to zinc condition and stray electrical current.
I have store bought zincs, they are not corroding as they should, I am in fresh water, which I think is the problem. I contacted the folks with Marinette Yachts and will go with the sea-alloy strips, what Eric did.
