wd 40 will naturally evaporate in short order. LPS is a much better product for long term protection. I buy it in 5 gal containers, and use spray bottles. I use it for long term marine engine storage. It is the same enemy tho... SALT. I have stored engines for years ,and they are still "slick" when unpacked. At one time I collected guns, and wd 40 covered gun metal would begin to rust in a few weeks.