pencero said:
Any petroleum based product with a fairly neutral ph balance is corrosive resistant. This was something I learned working a chemical plant nearby. I asked why people were diverting rem-oil which is used to clean guns of course, lots of workers were spraying it under their cars as a corrosive resistant chemical. It had only mixed results for preventing corrosion frankly, although its very effective at keeping bs off rims, and particularly brake dust off rims. For inside the frame, even tow ball grease or lithium grease is ok. Even cheap petroleum jelly from the dollar store is better than nothing in a spot you expect water and salt to mix up. Anyway, my point is only that I learned from working at the plant what a waste some products really are and what a value some others are. You don't need to spend big money and buy expensive chemicals and wands to resist corrosion. All you really have to do is look at the ph balance and corrosive resistant chemical properties of the main ingredients of many common household things and you would find that many products contain large amounts of the same corrosion resistant chemicals with fairly inert 'other' ingredients. What I learned from working at the plant was a chemical is a chemical. No need to overpay for the same chemical behind a different label over some bragging and boisterous claims from an advertisement!
Actually most oils and spray (white lithium) greases wash away quickly, at least if you were to put it somewhere where it is going to be open to the elements. They'll work, but you'll have to keep reapplying constantly. This is why a waxy product with body is more effective, as it is closer to an actual undercoating, but you have the ability to scrape it off much easier if you ever have to (and you can see what is underneath). Like cosmoline the factory used to sometimes dip things in instead of painting them. Vasoline, again, is better than a spray lube, but still doesn't have the body that will allow it to hold up better over time and will melt into an oily mess if it gets hot. The 3M stuff I had got was $10-$15, and about 3x the size of any of your usual spay lube cans. I've used the same can when I worked at the body shop, on my own frame rails, and various other things, and still have at least half a can. Most of the products are made for when you repair a new car in a collision, you spray it in the crevices/seams that were welded on/near (which is how I was introduced to it). Believe me, this is an instance where you get what you pay for.
I have an article on a late 60's Barracuda with 250,000 miles with the original owner in Alaska from a year or two ago. I remember specifically that it stated he used a "waxy rust inhibitior" made by Lucas on the undercarriage and engine bay. Although it wasn't a show car, it only ever needed the outer body to be repainted, and that was mainly due to rock chips from passing trucks.
There is a can of Fluid Film where I work now, so I'll have to get one and see where it actually lies between lithium grease/WD40 style lube/schutz/wax.
