I like and use waxoyl. Its expensive, but unless one has a fleet of cars
it doesn't seem worth the effort to make one's own. Personally, I doubt
that "rust inhibitors" are essential. I have experience with a 10 year
old Chevy Blazer and a 15 yr old horse trailer, each of which had been
"rustproofed" by spraying the bottoms with used engine oil. Rumor has it
that old timey Vermonters used to do this every fall, and then drive the
car down a dusty road to fix the treatment in place.
Oil washes off where direct spray from the wheels can get to it,
whereas waxoyl doesn't. But where the oil (and adhering dirt) stay, I can
tell you that protection is near perfect. The Blazer had 1/2 inch of oil
soaked crud everywhere underneath, but under that crud was the original
paint on the frame and body. The guy who installed a trailer hitch for me
was astonished to see a shiny black frame on a 10 yr old, 70,000 mile
Blazer that had spent it's whole life in Vermont. The horse trailer also
had shiny metal under the grunge.
The biggest drawback of the oil is the aforementioned grunge. Mercy, what
a mess when you tried to do anything under that car! (And things OFTEN
needed doing under it--don't tell me about the reliability of american iron.)
I compromise on my modern machinery. I have it waxoyled, and then I hedge
my bets by taking a pump oil can every year or so and shooting a little
clean engine oil in the door bottoms, the trunk lid lip, the front of the
hood, and in general all places I can reach easily through drain holes,
etc., especially where two pieces of sheet metal overlap (e.g. door
bottoms). The oil creeps slowly by capillarity and keeps these vulnerable
areas coated. Only drawback is that if the car is left unwashed for
several months, a black greasy line starts creeping up the bottoms of the
doors and trunk. Better that than rust.
Ray Gibbons, fighting entropy in Burlington, VT
|