Q & A — January 2003
By Capt. Ken Kreisler
2: Galvanic Corrosion, PMY Tries... Tuf Enuf
are galvanic corrosion and electrolysis different? B.E., via e-mail
Galvanic corrosion is the decomposition of one of two metals of different electrical potential--known as voltage--when they're immersed in an electrolyte. A natural battery is formed by two metals--say, a propeller made of Nibral (an alloy of nickel, bronze, and aluminum) and a prop shaft made of stainless steel--playing the role of anode and cathode, when they are immersed in seawater, an excellent current-carrying liquid. As electrons move from anode to cathode--that is, from the metal with higher electrical potential (less noble on the galvanic scale) to the one with the lower potential (more noble on the scale)--the metal deteriorates. Placing a sacrificial anode made of a metal, such as zinc, which has a high electrical potential, between the metals in the circuit will cause the zinc to decompose first and thus save the other metals.
Need help with a maintenance problem? Write to Maintenance Q & A, Power & Motoryacht, 260 Madison Ave., 8th Fl., New York, NY 10016. Fax: (917) 256-2282. e-mail: firstname.lastname@example.org. No phone calls, please.
Tries... Tuf Enuf
What about the product's cleaning abilities? I've never been one to keep a spotless bilge, so the Scrump's nether areas were a tad grungy. Nor have I ever been one to scrub bilges with brushes and sponges, so I added a little fresh water and let the mixture slosh around for a day or so, washing-machine-style. Tuf Enuf removed some grease and grime, but not all, thereby suggesting that a complete job might call for further applications.
Since the company says the mildness of the product makes it safe on fabrics and the environment, I also tried a little on fiberglass surfaces and vinyl upholstery inside the wheelhouse. It removed smudges, dirt, and even rust stains almost instantly. Cost: $9.95 per quart and $29.95 per gallon.—Capt. Bill Pike
Wallace & Sons Phone: (800) 223-5969. www.tufenuf.com.
This article originally appeared in the January 2003 issue of Power & Motoryacht magazine.