Corrosion Prevention

[marlinh]

As everyone knows, I brought home a mint 87 this week. I was wondering if I could get some input on tried and true procedures to keep this body from rusting away. I don't want to drive it in the winter, but that may become an unrealistic dream.

Has anyone ever sprayed something in the rockers to keep them from rusting from the inside? I do not want to drill any holes in the body since it is solid, but there is some access. Just wondering what other people have done and succeeded.

[Petros]

large amounts of LPS-3 sprayed to soak all locations where moisture and corrorsive compounds could collect. When I worked for a local aircraft manufacturer writing retrofit or repair procedures, I ran across a test one of the airlines was doing using different compounds in the lower parts of the fuselage. Although all aluminum, the lower parts of the fuselage would collect not just a lot moisture from condensation, but various coffee or soft drink spills, cleaning agents, solvents, etc. and it would eventually corrode out all of the fasteners, frame and skins. The airline tried various compounds by spraying it over the surfaces after it was cleaned, and than reinspected it at 3 month intervals. they found the LPS-3 gave the best resistance to corrosion and was applying it to the lower fuselages on their whole fleet yearly. It saved them millions of dollars in aircraft fuselage repairs.

There is another similar product I have used called "Corrosion-X", a bit pricy at $17 per 16 oz can but it too works well.

[dlb]

peter, do both of those products go on clear or are they more of a paint-like thing? i've never heard of either and wonder what they look like once applied.

[Petros]

the LPS-1 is clear, as is the Corrosion-X, the LPS-3 is heavier and kind of honey colored, but it goes on so thin it appears clear. It is some kind of synthetic oil compound, all are supposed to dry eventually to a non-sticky surface. Part of the corrosion process is an electrical ion exchange from metal to O2 atoms, this stops the ion exchange. It also works to prevent arcing on bad contacts or ignition circuits.

One of my co-worker, when I worked at Nissan many years ago, ran his old car through a big puddle and it stalled out and would not restart. He sprayed LPS-1 all over the wires, spark plugs and distributor cap, and under the cap, and it started right up and got to work raving about the wet start capability of the LPS-1.

[marlinh]

Gee Petros, is that your stash in your shop? I could have cleaned you out!

[Gottolovem]

Has anybody had any experience with the various spray on bed liner products.(under the car of course)

[Petros]

Not my stash, a pic I found on the internet. both of those cost about $17 per can, so that would be a pretty pricy stash!

I would not use bedliner as undercoating, it likely will trap moisture and corrosive compounds against the metal body. You should use a product designed as undercoating for your car. I would spend some time cleaning or pressure washing the underside, and masking off the parts you do not want undercoated, before you take it to a place to spray on the undercoating.

[marlinh]

My biggest concern is protecting the inside of the rockers. It's the hidden rust I am worried about.

[Mark]

I've used an asphalt-type spray-on undercoating in wheel wells before, but I didn't have the car long enough to see how it lasts. I assume it would have to be re-applied every year or two. It comes in spray cans and it's pretty cheap. I bought mine at Canadian Tire.

[Petros]

that is a good product, I have seen it before, but not common around here where rust is not a major issue.

[Mark]

I don't think under body rust is a major issue on the West coast here either, since they don't salt the roads. I assume Canadian Tire sells the stuff since it's a national chain and they all just stock the same products. There's a similar product used for spraying on old asphalt shingle roofs to seal them. The car stuff I bought smells just like tar, but it's pretty thin so I used a couple of coats. I remember it said on the can you could use it to seal "wounds" on trees from pruning as well so it's probably not ridiculously toxic. I think it cost around $ 6-8 for the can.

[Jooseppi Luna]

I've used an asphalt-type spray-on undercoating in wheel wells before, but I didn't have the car long enough to see how it lasts. I assume it would have to be re-applied every year or two. It comes in spray cans and it's pretty cheap. I bought mine at Canadian Tire.

The only caution is that you cannot oilcoat the bottom of the car then because oil might damage the coating. I think the asphalt undercoating is meant to be "lifetime" -- my '82 Mercedes diesel has it from the factory and it is only now starting to deteriorate (it is unsticking from the car and creating little water pockets...).

There's a fellow I know from the old Mercedes world who has been a mechanic in New England for 30 years and is a car nut. He says that oilcoating is one of the best things he knows for rust prevention. There are still some places that do it -- ask around. The oil basically keeps the water at bay and so does not let the O in the H2O mess with the Fe.