Re: plug broke off in head of Merc cruiser
Well... a few people have disagreed... and to each there own.
But... why does the manufactorer not recomend it? They recomend 20 other greases and oils and sealers for all over the engine and drive... but not anti-seize.
When you take 2 disimilar metals, and you add an electrolyte... you essentially make a battery... and electricity expidites corrosion.
If you take the metal of the engine, the metal of the plug, and the metal of the antiseize.... well that's a whole lot of metal.... add water to it... especially salt water... and yer scaaareewd.
Truth be told you can get away with it on a cast iron head. As long as you just use a dab... and you FOLLOW service intervals and don't overtorque.
You don't want to use copper or graphite based antiseize with anything... as copper and graphite are highly reactive. Nickel base is less reactive. Cast iron isn't terriblely reactive. But if you have an aluminum head, such as on certain sterndrives and almost all outboards... aluminum is highly reactive, and i'd never use anti-seize.
The deal is... is that as long as you do not overtorque your plugs, and you change them every season, you shouldn't have a problem.... and if you do you probably have way to much spray hitting your motor... which is a different story all together.