corrosion around head

[dag]

Guys,

Just wondering if a little rust and corrosion is normal around a watercooled head? I just ran my boat in brackish (salt+fresh+cedar) water for the first time and I took the water jacket off when I was done and noticed some corrosion. This is the first time I have ever ran the boat in anything besides fresh water, and the guy before swore he ran in nothing but fresh water. I would think this is normal. Fresh water will corrode metal but not as fast as salt, right?

[BoatDoc]

corrosion...where to start. without getting too scientific about it, i'll try to keep it simple. yes, fresh water can cause it. remember, even in fresh water there are plenty of things in it that can rust or corrode metal. you also have the idea of differing metals. if you have aluminum and steel touching (steel bolts in an aluminum crankcase for example) they can react and cause corrosion. if you run a nitro boat, there is methanol in the fuel. methonol reacts with aluminum, causing corrosion. if you have a gasser, and have to use "reformulated" fuel, then you get a little methanol along with your gasoline (usually up to 10%). of course, there is always the corrosion troll who sneeks into the workshop at night and wreaks all sorts of havoc. and free O2 in the air can react with steel parts also, causing rust. the key is to routinely inspect the engine and running gear and keep them all clean and well lubed.

[Ron Olson]

After running it in Salt water or nasty pond water, spray some WD-40 or equivalent into the cooling line to clean out the inside. Algae and other crap will build-up on top of the head, allowing heat to build up.