Andrew Birkett's nobugs.org
This rusty metal part lives underneath the mudguard on my motorcycle, where it gets sprayed with water and muck all day long. After 12 years, it’s in a sorry state. One of the bolts which holds it onto the bike sheared off when I tried to remove it. I had to use all of the tricks to get the remainder of the bolt out (penetrating oil, leaving it for day, heating it, hitting it with a hammer, hacksawing a groove into it, impact driver and lots of patience).
Anyhow, rather than sticking it back on the bike (and thereby storing up trouble for next time) I thought I’d apply some science - electrolytic rust removal.
Impressive name, but all it involves is a bucket of water with some soda crystals in it, and a bench power supply whose positive terminal is connected to a ‘sacrificial’ lump of steel, and whose negative terminal is connected to the rusty part.
Half an hour later, and the result is ….
Pretty good result, huh? Especially given that it required almost no effort. The metal part bubbled away in the bucket for a while, and then a quick wipe with some kitchen roll is all it needed to get to this state.
All the corrosion is gone. There’s still some pitting, but that’s due to the metal lost during the years of corrosion - there’s no way to put that back really..
Yay for science!