March 21, 2008 - Rust!
by Michel & Jane DeRidder

We are not experts in any field and certainly not where it comes to metallurgy or chemistry. However we are curious about most things. The amazing rusting that has been taking place on a bit of chain hanging on the river piling behind us is an interesting and frightening case in point.

Our present pilings were placed in the river in 1981 and over the years several different boats have been moored there. One owner tied his mooring lines with a few links of chain and a big shackle. Following boat owners have used their own lines but that old length of chain is still hanging onto the piling, its links steadily corroding away as they dip into each high tide. It shows us how rust takes the life out of a bit of steel.

Rusting chain links.

I have encountered rust here and there since I was a boy when my first bicycle needed acid treatment to rid it of the stuff. Over the years I have noticed that tools, cars, fastenings, everything made of steel seems to want to rust. An amazing example that we happened upon was on Canton Island in the South Pacific in 1983. Canton was by then an abandoned US missile-tracking base with, amongst other curiosities, an immense 'room computer' filled with electronic valves and relays. On the south end of the island was the British seaplane refueling base. There, rust had taken an amazing toll. Parked cars and trucks were slowly disappearing. The most astonishing sight was the remains of tall transmitter antennas. Piles of rust resting on and around the concrete bases and crumbled bits of angle iron was all that was left of the steel girders and their braces. The rust was turning into red dust that was blowing away into the lagoon.

Canton antenna tower.

When we built Magic Dragon we tried to minimise the rusting possibilities by, as much as possible, not using steel where it would be exposed to moisture. We've managed to keep her steel keels and rudders from corroding under water with barrier coatings and constant zinc protection. But zinc is sacrificial and so it goes for the galvanizing of chain and anchors. We use anodes on the anchor to extend the life of the galvanizing. Rusting tools and other things can be protected with a so-called Rust Converter as a quick fix when paint coatings are in the too-hard basket sphere. Our 1967 Honda motor cycle has survived life aboard and on beaches thanks to the above, as well as greasing to keep moisture and oxygen away.

Over the years we have been admirers of steel boat owners. With today's epoxy coatings, the first few years are ok as long as the barrier coatings are properly applied and do not get damaged. But sooner or later the challenge of keeping rust away can get to be a serious task. How many times have we heard the bang bong bing of rust chipping coming from the bowels of steel hulls, or their decks for that matter! And it is a serious matter that must not be left unattended. We have seen steel boats much younger than Magic Dragon turn into lace work. It seems to happen to decks and cabin sides as well as hulls. A sad sight when you see a beautiful yacht with rust cancer under its immaculately laid teak decks.

Rust on a boat.

A while back in New Zealand the skeleton of a missing crewman was found in the chain locker of a big fishing boat, causing a nightmare of investigations for the rest of the crew. But an engineer friend of ours says that it is regulation to blow fresh air in rusting steel compartments of a ship before sending in workmen. Apparently rusting steel uses up the oxygen in a closed up chamber.

Looking in the Britannica dictionary I read "RUST: the reddish brittle coating formed on iron esp. when chemically attacked by moist air and composed essentially of hydrated ferric oxide." And today, thanks to the Internet, we can get all the information we could need about rust, how it forms, and how to prevent it. Type RUST in Google and there you have it. Manufacturers push their various rust prevention systems there as well, from coatings to electronic protection. Look up http://science.howstuffworks.com to learn more, as I did. Other dictionary definitions are "Rust bucket: a rusty old ship". We also read, "To rust: to degenerate esp. from inaction, lack of use or passage of time." We know that feeling, all right. If we could take macro pictures of our own cells they may look reddish and brittle too!