Rust Prevention Advice

[Anderson]

I'm currently in the process of (very likely) buying either a 1970 Eldorado Coupe or a 197X Fleetwood (I'd been gunning for the Fleetwood but every one I ran into had significant reasons to give me doubts or was outside my budget and there's a 1970 Eldorado that I'm quite happy to work with).  Given the known rust issues on Cadillacs of that vintage, aside from "don't drive when it has recently snowed", what would be my best bets for limiting or preventing rust?

[Bill Young]

First of all , I would not buy a northern car that has been driven in salt. Many don't know that the salt does not activate till above freezing. When road salt is laying inside of body panels , frames etc. even in summer salt rot activates with any moisture.

[Anderson]

I've set either "rust free" or something quite close (nothing beyond surface rust or limited panel replacement) as a condition of a purchase.  Of course, my father bought a 1970 Mercedes 280SL when I was a kid (I just sold it, which is what kicked this search off) and it had rust issues from having been parked at an apartment complex on Atlantic Avenue in Virginia Beach, so current car condition trumps where the car is notionally parked.

[Scot Minesinger]

Limiting rust in a car you own, built prior to 1980 when not much rust prevention was built in by the automotive factories:

1.  Yes do not drive your car in snow.
2.  Often salt is applied to the roads when there is no snow or ice, just because it is forecast but does not materialize - be careful do not drive when salt is on the roads
3.  After it snows and salt has been applied (or salt was applied and it did not snow), it takes two or three good rains to clear the salt, so make sure there is no white salt haze on pavement before driving.
4.  Do not drive when the roads are wet, even in the morning when it is sunny and nice, but roads are wet from last night of rain.
5.  Use a spay water-less car cleaner to keep your car washed.  Griot's sell a nice product - speed shine - I use that.  Do not use a drive thru car wash!
6.  Do not drive in the rain.
7.  Store the car in a tempered, or ideally heated, cooled and dehumidified garage when not in use.
8.  Although tempting, do not drive your car to the beach for a summer weekend or week long vacation, even if it will be under cover when not in use.  The salt laden air will rust damage your Cadillac.
9.  If you live near the ocean (within a mile), consider storing your car inland and do not drive it much near the ocean.
10.  In general, always keep your car out of a moisture/salt potential environment whenever possible.
11.  Raise car on jack stands or lift and inspect for rust.  Repair and damaged ares to stop more rusting.
12.  As a precaution apply rust proof paints and finishes to undercarriage that resemble factory finishes.  Otherwise protect from potential rust with protective coatings that do not detract from appearance - no Z-barting for example.

Only exception is drive your Cadillac to and from GN and it will of course get rained on - no avoiding it.

Enjoy your Cadillac!

[hornetball]

Vinyl tops are the devil . . . .

[Eric DeVirgilis CLC# 8621]

Moisture is the enemy of almost all things man made. In a nutshell, the less the car is allowed to get wet or subjected to moisture, the better. This is especially true in cold/damp weather which will dramatically extend drying time in  moisture entrapment areas, which in older cars are innumerable. Later cars were better designed in this area, as well as having better treated sheetmetal which was minimal in older cars (particularly before 1977).

It was also common for older cars to have been "rustproofed" can deteriorate over time exacerbating the issues it was originally intended to combat.

As mentioned earlier, cars equipped with vinyl roofs are particularly vulnerable to rust issues and I would strongly advise that water never be allowed to get into the roof moldings where it will get underneath the roof material becoming absorbed by the underlayment destroying the metal underneath.

Ideally, traditional bucket and hose washings should be done rarely, if at all. There are plenty of ways of cleaning the exterior without ever taking a hose to a car.

[Alan Harris CLC#1513]

My body man told me that one of the constant things he hears is that people wash the car, towel it off, and then put it back in the garage. They then wonder why the car rusted so badly. According to him, the best thing to do after washing and drying is to drive the car to blow the water out of the crevices of the body or at least leave it out long enough for the wind and fresh air to dry everything.

A wet car in a garage can stay wet for days! Water is the enemy!

[jdemerson]

As one who does most of my driving in Vermont and Upstate New York, where there is ALWAYS salt on the roads in the winter time, I strongly endorse Scot Minesinger's list of points above.

I would emphasize that salt is far more the enemy than water, though it is certainly good to avoid water standing on the car. if/when it does get wet, it's a good idea to drive it rather than park it -- as Alan Harris recommends.

There is conventional wisdom that factory rust-resistant coatings have solved the problem of corrosion in recent years, and that rustproofing is no longer recommended. There is some truth to this (for example, '77-'79 Cadillacs were less rust-prone than the '71-'78 generation), but the rust problem is very far from being solved in those environments where road salt is needed and used in the winter. There is much evidence of rust-through on cars and trucks less than 10 years old here in Vermont and throughout Upstate New York.  SALT is the enemy!  My suggestion for NEW cars is to check out a product called "Corrosion Free" which is made in Canada and was adopted for government-owned vehicles in Canada. it is clear and it creeps -- not like Ziebart (which I used in the 70s). The quality of the application is important. I have no advice about this product when it comes to 50-year-old Cadillacs. Just keep them away from salt!

John Emerson
1952 Cadillac Sedan 6219X

[Lexi]

In addition to Scot's comments, oil spraying is perhaps the best system to use for rust protection. Krown works well. Nothing comes without a disadvantage though, and oil spraying is messy and should be applied on an annual basis, thus adding to cost. It's advantage is that it creeps into all the 'nooks and crannies' where moisture would collect, if applied properly. In the late '70s I saw a '50's Turnpike Cruiser being oil sprayed by it's owner. Car was in Canada, and used as a daily driver including all winter driving. This was the original owner and he had been oil spraying this car since new. He obviously spent much time looking after his car which appeared to be his pride and joy. It looked 'mint', which was quite something for a white car in this 'rust belt' back then. Not a sign of rust. Original paint, looked showroom condition. It sparkled. He had an elaborate system for applying the oil which he said came from the aircraft industry and was similar to trany fluid but less viscous. Fellow said he was going to look into doing this commercially. I will never forget that day and how well his car was preserved. My experience is that oil covered metal repels moisture. How many rusty parts have you picked from a junkyard that were grease and oil covered? Clay/Lexi

[cadillacmike68]

Just find a good car and drive it like you stole it. 

I get rained on most of the time I'm out in the 68 and even when it doesn't rain the humidity is high enough here to condense on the car as soon as it gets dark.

I wash the cars in the driveway and use car washes. No biggie, it's usually hot enough to dry off completely before I put the car away, and it hasn't rusted up in the 15 years since I've had it painted.

And I take it to the beach. I do cover it at night (or stay where there is a garage) and wash it when I get home.

But I won't take it up north in the winter. The newer ones (Fleetwood & CTSs), sure, if I have to, but not the 68.

[Jim Miller]

Following Clay's post, I recall years ago in Northern Ohio, a lot of guys would spray the underside, inner doors, and boxed in areas with ATF or thinned oil. I also remember a neighbor who did that, but also would wash his car then take a bucket of clear water, add a cup of kerosine, and sponge the car down. Then chamois it dry. His cars were always shiny with no rust. But they smelled like a locomotive.