Heresy in the Form of Titanium....

[ebb]

The metallurgists have a convenient voltage separation table called the Anodic Index in which metals are roughly listed in the same order as their 'nobility'. The closer two different metals are the less likely they will react.

Salt marine environments have the closest voltage separation: .I5v, ie different metals THAT close on the scale are less likely for one to become anodic. Gold and silver are close enough to leave one another alone. Titanium and silver are next to each other on the list. (Now it starts getting funny...) Monel and high nickel copper alloys - brasses and bronzes all fall somewhere in the same .15V protection zone, with silver and titanium.

However, seacocks these days are made from copper alloys with high levels of zinc in them, often way above the metalurgical safe level for an alloy not to self leach. Zinc is down there between aluminum and magnesium! We went into this in some earlier posts. Intuitively, I think adding another metal to the mix is asking for trouble. Do we know how inert titanium is? It may be just the voltage, just the cathode that sucks the zinc out of the valve. I've heard that T, is used for the thruhulls on aluminum boats and those two are at opposites ends of the galvanic table. But I don't know. Certainly would mean it don't wanna be a battery. If true.

But if it truly dosen't react with salt water, maybe it will work with a seacock, if you use a seacock you need nontapering matching threads on the thruhull. BUT, my friend, they do put titanium in the ANODIC index (but not graphite.) Let us know how it works out

(Just had a look at Bill's post above. The Russian is saying, like we know, that like belongs with like. It doesn't sound like he really knows what your application would be. If it were available, the very best hole in a boat would be a matched pair of thruhull and seacock in SILICON BRONZE. There just isn't a better alloy than that for seawater. IMCO, Marelon is next. IMHO, after that... there is nothing else! Nothing.)