What is WD40 and what is it good for?
To understand how WD40 might work as a lubricant, we need to first understand its chemical composition. To do this, I went to WD40’s Web site. While the marketing pitch lists the ingredients as “secret”, the MSDS indicates the following: 60 to 70 percent petroleum distillates, 15 to 25 percent base oil and 2 to 3 percent carbon dioxide so it would appear that WD40 is simply a combination of petroleum products, mixed with a propellant (CO2), in lay terms kerosene mixed with base oil. There are no rust inhibitors in WD40 to prevent corrosion; however it works as a good loosener and can remove surface rust as a solvent yet will not protect the surface against rust and micro-pitting nor is it a good lubricant. WD40 is marketed as a household lubricant and rust remover for those small jobs.
