Protecting Your Land Rover from Rust and Corrosion

Author’s Note — This article was written for the Land Rover community in 2005, and updated in 2014. The ideas in this article are current and applicable to any motor vehicle that you want to preserve. Feel free to substitute Jeep or Toyota for Land Rover, if that’s what you own.

Land Rover products, with their mix of aluminum and steel body panels, are quick to corrode on salt covered American roads in winter. Range Rover Classic, Discovery and Defender models are especially prone to corrode. Many of these trucks in the Northeast salt belt show signs of rust when only 2-3 years old. The newer Range Rover and Freelander models are less corrosion prone because they are more effectively rust proofed at the factory, but even these newer models are prone to rust and corrode when driven in high-salt areas like Vermont, or when off-roaded and submerged in water.

In fact, off-roading presents a particular corrosion problem for Land Rover owners. When cars are driven on wet roads the water sprays onto a clean undercarriage and dries fairly fast. Furthermore, the water is limited to whatever sprays up from the tires. But when off-roading the vehicle may be immersed in water, filling many bare metal cavities that are always dry in on-road use. Additionally, the underside gets packed with mud that can trap and hold water for days or even weeks. In some cases the mud packs into an area and never dries as it gets wetted by tire spray and holds water essentially indefinitely.

Discovery II Models are particularly prone to frame failure from internal rusting that happens when winter salts get into mud that’s trapped in frame rails. Newer Land Rover products — LR3, Sport, and even the full size Range Rover are showing more chassis corrosion in states where liquid snow melter is used heavily.

I spent considerable time looking into the products available to prevent our Rovers from rotting away, and in this month’s column I report what I learned. First, I found that there are a few other types of rustproofing and undercoating products on the market. Although at first they may seem the same I found they are actually quite different. The materials I looked at are

  • rust-eating paints;
  • rubberized undercoats,
  • tar-based undercoats,
  • and wax and oil-based undercoats, which I found to be best.
  • Rust-eating paints Like POR-15 and Extend contain acids that dissolve rust combined with paint to cover the bare surface. These products work well to halt rust when painted over clean rusty metal, but they do not work well if the painted part stays wet for a long period — for example, when water and mud spray under a vehicle and stay damp for days. Furthermore, the paints to not offer and resistance to chipping from gravel abrasion and they do not bond well to painted surfaces. Finally, many of these compounds are not effective at all on corroded aluminum.

    I concluded that rust-eating paints are good when painted onto a bare chassis. For example, they can be great when painted onto a Series chassis when doing a frame-off restoration. And they can be effective when painted onto damaged metal as a spot repair. But they are not very effective as a protective undercoat for an entire vehicle.

    Rust eating paint is a good product for a restorer, a chassis builder, or someone doing spot repairs. But it’s not a product that is suitable for rustproofing entire vehicles. A bare chassis that has been painted will still benefit from being sprayed with a wax and oil based treatment as described below.

    When we treat new vehicles, or newly restored vehicles, we do advise painting all bare metal with POR15 before Waxoyl. We also advise POR15 pre-coating when large metal areas are scaled of rust on older trucks.

    The next product — rubberized undercoat — is not marketing as a rustproofing product. It’s marketed as “undercoating”, whatever that is. Despite that, many people buy spray undercoat from 3M and others and cover their Rover chassis in the belief that rustproofing is what they are getting. It’s not. The rubberized product tends to peel away from the metal over time and trap water between the undercoat and the metal below. I am not a fan of these products. Once they crack or get cut water gets under them, and rust begins.

    Rubberized undercoats are intended to provide some measure of sound deadening and gravel abrasion protection to car chassis. They are not a rustproofing material. I suggest you avoid these products because of the risk they will trap water and cause damage later on. You can accomplish the sound deadening and gravel protection just as well with the wax and oil based compounds described below, and by using materials like Dynamat on the interior surfaces. We can do that work too.

    Tar-based rustproofing products were marketed in the 1980s by several chain store operations. They have largely fallen into disuse. Tar based products are potentially hazardous, and they are difficult and messy to apply. They do not offer any benefits I could see over wax/oil based products and they have a number of disadvantages.

    Some old tar-based products also trap water like the rubberized undercoats I looked at. The hard undercoating applied to 1960s Porsche automobiles was a good example of that — we peel away great sections of undercoating to find steel underneath that was perforated by rust. In fact, you could peel undercoat from a car that's been dry for weeks and find damp metal trapped underneath. I suggest you avoid such products today.

    The final category is wax and oil based rustproofing. The product is a mix of paraffin wax and petroleum oils. The oil stops the rust and corrosion, and the wax keeps the oil from washing off. Many companies have produced wax and oil rustproofing formulations over the years. After review, I concluded the wax and oil based products are be best for our Rovers. They are safe to handle, easily applied, and they do a good job of protecting the entire vehicle. They are equally effective on steel or aluminum. They are easily touched up if scraped or worn, and they won't trap water when they get old. They can actually be applied to a wet vehicle and they will displace the water to bond to the metal!

In fact, Texaco developed a wax and oil based rustproofing product to corrosion proof the holds in cargo ships. The material was poured into a flooded cargo hold, and then the ship's pumps were used to pump the hold dry. As the water receded the rustproofing material would stick to the sides of the hold and finally it would cover the bottom. It was said to be quite effective, and it was used until the environmental laws changed and ships could no longer flush their holds with seawater.

A product that worked in a saltwater environment like a ship's hold sounded like just the thing for a Rover in salty winter water and summer mud.

When I investigated wax based rust proofing products for Land Rovers the name that kept coming up was Waxoyl. Many people in the UK and Europe praised the stuff, but it was not available until recently in the US because of EPA restrictions on its shipment. Waxoyl is made in Switzerland.

The art is in blending the oils and waxes to get the best result, and looking at the testimonials it was clear that the Waxoyl people were the leaders. It was frustrating trying to buy the products, though. It was legal to ship motor oil, and it was legal to ship wax, but for some reason it wasn't legal to mix the two and ship that? It didn't make sense. Recently the EPA came to the same conclusion, and Waxoyl is now shippable in gallon containers through UPS. Finally we could buy it!

Waxoyl is recognized as the premier product to prevent rust and corrosion of new Land Rovers. There is no better protection for a vehicle that will be immersed in water or run on salt covered winter highways. Waxoyl is also very effective at halting the progress of rust on older vehicles.

Waxoyl appointed Rovers North to distribute Waxoyl for the Land Rover market, and they in turn signed Robison Service up as the pilot installation center. Waxoyl offers their product in bulk for professional installation and in spray cans for hobbyist use. Rovers North started selling spray cans of Waxoyl for home installation. Then they began selling the bulk professional product, which can do a much better job. 12 years ago, the Waxoyl factory rep came to Robison Service to train our staff on the products and their application, and we remain their pre-eminent installer.

For home use we have Waxoyl in spray cans. It has been available in America for some time, but its effectiveness is limited. The spray cans do not propel the Waxoyl with enough force to reach deep into recesses and holes. The professional product is the same material, but it is applied with special spray applicator guns using shop compressed air. The use of these special applicators allows us to spray Waxoyl into areas like bulkheads, frame rails, and inside of other enclosed areas out of reach of a home spray can. Waxoyl is much more effective when applied in this manner.

What follows is the story of how we rustproof a Land Rover using professional spray equipment. The Land Rover in the pictures is a 1997 D90 owned by Pat Macomber of the West Connecticut Rover Club.

We begin by power washing the entire underside of the truck. We use a gas-engine power wash system that is very effective at stripping off grease, mud, and debris. These power washers are also effective for cleaning out a Rover after an off road run. Our pressure washer is quite a bit more powerful than the spray wands found in self serve car washes. You’ve got to be careful handing it — the water sprays out under such high pressure that it can slice your skin like a knife if it gets too close.

Next we use wire brush scrubbers to remove any scale and flake under the vehicle. This particular Rover has been a pampered pet, so there is not a lot of flake rust to remove. On older trucks this part of the job can take several hours.

Next we apply the clear Waxoyl. The clear material is a non-hardening product. Using a small tube that we can insert through any ¼-inch diameter hole we spray inside the doors, in the firewall, in the body cavities, and inside the frame rails. The Waxoyl spray fills enclosed areas with a mist that settles onto the surfaces. This is how we coat the entire inside of a door without taking the door apart. A vehicle that has been properly treated will have a slightly sticky film of protectant on all the inner metal surfaces. On many Land Rovers some disassembly is needed to get into all the areas that need treatment. For example, the area around the tail lamps in Discovery should be treated, as should the compartments under the seats and in the firewall of the Defender.

The most time consuming part of the job is fogging all the areas that can fill with water when off-roading. Conventional rustproofing is limited to spraying the underside of the vehicle and perhaps fogging the doors. Doing a good job on a Land Rover takes quite a bit more time and effort. In addition you need a lot of product knowledge — you need to know where the nooks and crannies are in order to treat them!

Next we spray the black Waxoyl on all the exposed surfaces. Black Waxoyl is thicker and dries to a hard black finish. Hard is a relative term; in this case it dries about as hard as the body of a candle. The black Waxoyl stays tacky for a few days. We usually tape off the springs, exhaust, and other undercarriage parts that we don’t want painted.

After letting it dry an hour or so we will go back and spray a second coat into the areas where gravel and water spray from the wheels. Those areas (wheel wells and rockers) see the most wear. People who run in a lot of mud should anticipate re-doing them periodically as they wear the Waxoyl away.

Once the truck is done we generally wash and wax it to ensure no stick residue remains on the paint. Waxoyl is not harmful to paint, but it can make the truck look dirty if sticky mist gets on the paintwork. Waxoyl overspray can be cleaned off with mineral spirits or tar and bug remover.

Black Waxoyl gets quite thick in cold weather. The process is best done in a 65-85 degree environment. The material will not spray well in colder weather, and it will be runny and difficult to use in hotter weather. In colder weather we heat the Waxoyl tanks by immersing them in hot water before spraying.

Preparation of a car can range from a quick wash on a new truck to days of scaling and metal treatment on a vehicle where rust already has a toehold.

If the vehicle has significant rust that will have to be repaired for Waxoyl or any coating to be effective. We can do any rust repair needed but that is a separate process.

The actual Waxoyl application takes about half a day, plus whatever time is needed for drying after power washing and drying of the Waxoyl.

New cars and trucks can usually be treated in one day but they should still harden overnight. Older cars with more intensive prep needs should be scheduled for several days.