In Florida, rust is the enemy to exposed steel tools. With the constant rain and high humidity, exposed steel quickly starts to form a layer of rust. I have been very impressed with electrolysis for rust removal that I started to wonder what was the best rust preventative. Below are links to some tests done on the internet. I have avoided the tests performed by the manufacturers themselves as they obviously show their product was the best. I can’t guarantee tests test are 100% objective, but they are interesting.
Here are some sample photos from the above tests:
It seems that EEZOX and BoeShield T-9 are definitely heavy duty rust inhibitors and seem to perform quite well. However, was surprised to see where WD40 was used, it performed quite well.
I have always heard that wd40 causes rust because it strips away the grease, contains kerosene and evaporates away. That statement is partially true. I think what happens (particularly with bicycle chains) is that the superior grease protection gets stripped away when the WD40 dissolves it, the bike is left outside and that chain is neglected and never oiled for a year. Had the chain received regular wd40 treatments, it would not rust. Despite popular assumption, it does NOT contain kerosene.
From the WD40 website:
“How long does WD-40 last after application?
While this may vary depending on the application, WD-40 remains effective even after it appears to dry. The corrosion and rust protection ingredients remain adhered to the surface. External conditions may, of course, require additional applications of WD-40for maximum protection.”
As you can see, regular applications are recommended by WD40 themselves. After you use a tool, give it a light spray and wipe it down after each use. The water displacing properties of the lubricant will remove the moisture from the metal, coat it with the lubricant and deposit corrosion inhibiting chemicals.