Frank wrote: "I have twin Bravo
3 outdrives on my boat. Should I stay with Mercruiser zinc or can I switch to
Martry zinc at 1/2 the price? I go thru 2 sets of zincs a year."


Frank-MERCURY MARINE changed from "regular" zincs (real 99 and 44/100 per cent
pure zinc) some time ago, largly due to corrosion trashing the carrrier bearing
areas of "duo-prop" drives, those dual stainless props were too much. I
understand there are lawsuits....
They now recommend an annode made of aluminum/indium for salt water (magnesium
for fresh water ONLY) on all the drives-(it weighs than zinc and and more than
magnesium). They cost more than regular zincs, can be had at West Marine
rather then the dealer for some savings, and I haven't noticed any
difference...in 4+ years, except some three months ago I developed major
corrosion tbl-if I had the alum/ind. annodes maybe it would not have
happened...don't know as I've pulled the boat out of the marina.
A new Alpha-1 drive is some $6500.....your's a bunch more...I'd follow Mercurys
recommendation!
Good luck
Mike