A Forensic Rust-Proofing of an 80 Series Land Cruiser (1 Viewer)

[kw90surf]

Good day all, and attention rust-belt owners, prepare for a lengthy post.

I wanted to share with you the rust-proofing job I just did on my 80 series.

I live in Nova Scotia, Canada, and I am going to claim that we have one of the worst, if not THE worst climates going as far as rust is concerned. Not only are the roads salted in from early November through late March (or worse, a chemical brine solution in some areas that is absolutely caustic), but it's not like winter arrives here and temperatures stay below zero (centigrade), making for a salty, but dry vehicle like in the Prairies. Nope, it's constantly wet and sloppy as snow falls, turns to rain, freezes, melts, goes below zero again and the roads are salted once again. So not only is your vehicle salty, but it's also constantly wet. Not only that, but we live on a peninsula on the North Atlantic, and see lots of rain and fog throughout the year along the coast. This means that even in the summer months, any piece of metal left outside and unprotected for a day or two is going to flash rust due to all of the salt in the air, even if there's no rain. It's infuriating.

The takeaway from all of this is that vehicles absolutely disintegrate here. Usually they're rotten and structurally unsound before they wear out. An unprotected vehicle driven year-round will last 6-7 years before panels are perforated from rust and brakelines are blowing out. Unprotected but summer-only driven you'll probably get 15 years before the same happens. A diligently rust-proofed vehicle might last 15 years here if used daily year-round. And as any of you who have dealt with rust in a climate like this know, once the rust starts, it moves quickly and it's really tough to stay ahead of it. As such, many people here opt for rust-proofing of various sorts. The most popular are:

• asphalt/tar/rubberized undercoat - anyone who knows anything knows that this stuff is the kiss of death. Not only does it miss the nooks and crannies (which is where the rust starts anyways), but after a little while it invariably develops cracks or separation from the surface, traps moisture and salt, and then rust starts developing rapidly out of sight. And it's heinous to remove.

• oil-based undercoat - by far the most popular and effective. Several chain businesses (Rust-Check, Krown, Canadian Tire) will apply their own formulation for around $180. An oily coating is sprayed under the vehicle and inside the engine bay which seals out moisture, salt and oxygen thereby preventing rust. Most chain places will drill holes in the tops of the rocker panels, the doors, tailgates, etc. to spray the oil inside the panels, and then have 360* wands that spray inside the frame rails as well. These coatings have the added benefit of lubricating the moving parts on the underside, and the added downside of swelling rubber in some cases (Krown) and trapping dirt, making the underside an oily disgusting mess that covers you any time you work on it. The great thing about them is they require little to no prep (a relatively clean underside is all that's needed), they self-heal (if abraded the coating will re-form), they can be applied effectively over existing rust, and they're good at creeping. This means they'll seep into all the nooks any crannies by themselves, so if applied thoroughly you know you'll have complete coverage.

With this being said, an oil-based undercoat seems like the obvious choice, and every vehicle I've owned to date has been protected with some form of oil-based undercoat, and for the most part they've protected them well. But, there are a few other downsides I've observed:

• They usually need to be re-applied annually to remain effective;
• They're all prone to wash-off to varying degrees (flip side of being good at creeping), which means that in our wet-winter climate with constant spray, the leading edges of items like axles, knuckles, steering parts, driveshafts and crossmembers will wash-off throughout the winter and those parts will begin to flash rust. As the years progress, this just continues to slowly spread.
• The heat of the engine bay causes these coatings to run off, meaning engine bay fasteners and aluminum parts end up corroded anyway.
• A pressure washer will take the bulk of the coating off, which happens when you wash your truck after four-wheeling.
• As the years go on and the coatings layer up, trap dirt and dry out, they tend to make a crust that can become solid and trap moisture like a rubberized coating, meaning every 6-7 years or so you need to pressure wash the oily dirty crust off and start again

With my previous Jeep XJ and now my '93 F250 I've been experimenting with Fluid Film mixed with toilet bowl wax, heated up to a liquid state and sprayed on with an air-fed undercoating gun. Fluid Film works great on its own, not creeping as well as red Rust Check but better resisting wash-off. That said, it does still wash off, and the toilet bowl wax I have added has been to help act against this tendency. So far, so good, and the coating under the Ford held up reasonably well after one winter. It still showed signs of wash off on the leading edges of the underside components which did flash. It also doesn't solve points 3, 4 or 5 in my list above.

Because most car/truck enthusiasts are well versed in the effects of corrosion and the effectiveness of undercoatings here, the general rule is that if you love it, or it's old and rare, you put it in storage for the winter. Generally, a vehicle that has red Rust Check applied annually (the lightest and best-creeping undercoat) and stored every winter, it should last indefinitely. And so for the last 3 years since I bought my 80, that's what I've done with it. But with my 4 week on, 4 week off schedule, I'm only getting maybe 4 months of use per year out of my 80. I don't necessarily wish to daily drive my 80 in the winter, but I would like to have it available for nasty snowstorms and winter adventures without watching it deteriorate before my eyes. And, even if I don't end up using it in the winter, I wanted it as protected as humanly possible.

So, I did a lot of thinking and a lot of research. In that, I stumbled upon a product called Cosmoline. It's a paraffin wax based product that has military application and dates back to WWII. It was originally used for protecting rifles and other military equipment against corrosion in the medium to long term. Basically, it applies as a wet, liquid coating, then the solvents flash off and you're left with a dry, amber wax coating that is extremely resilient. It will not come off even with a pressure washer or cleaner/degreasers and scrubbing. It takes petroleum solvents to remove it (mineral spirits removes it pretty effectively). There are currently several companies selling a cosmoline-based product, including Amsoil Heavy-Duty Metal Protect, CRC Heavy Duty Corrosion Inhibitor, and Cosmoline Direct "Rust Veto" RP-342 (all pretty much the same thing).

Cosmoline Direct (Cosmoline for Sale - Cosmoline Direct Rust Preventives, Sprays & More - https://www.cosmolinedirect.com/) sells several versions of this Cosmoline product, such as an "industrial grade" version, a version that's tinted black, a "hot-melt" version, and so-on. Prettty cool site and it's not flashy at all.

Here are a couple of YouTube videos about Cosmoline as undercoat:

1 year Cosmoline RP342 test:


1 year CRC Heavy Duty Corrosion Inhibitor vs Fluid Film test:


With this product looking promising as a coating that would resist wash-off and last a long time while not making my cruiser absolutely disgusting to work on, I decided to run a test on it. I ordered some aerosol cans of CRC from Amazon, as none of this stuff was available locally. I applied it to the polished alloy wheels, chrome bumpers, mirrors, running boards and aluminum back rack on my F250 before the salt hit the roads in the fall. My thought was that the application of it in these areas would give a well rounded test of abrasion (running boards), wash-off (front and rear bumpers), corrosion resistance (polished wheels and rack), and how much it trapped dirt. I applied one coat, poorly (it was drizzling and I had to wipe the water off the parts before applying the product, and water was falling on it while it dried.

This picture shows how the coating looked after it had dried:

After a long salty winter, here's how the front wheels looked. Lots of trapped brake dust:

5 minutes with mineral spirits and a rag, however, and it looked like this again:

The wheels looked exactly the same as they did when I coated them 8 months earlier (the surface rust on the lug nuts was already there). The bumpers and rack were much the same. The abrasion of constant stepping took some of it off of the side steps, and there was the odd spot on the rack where a strap did the same.


Happy with the test results, I ordered some more, this time from Cosmoline Direct, and decided to tackle the 80 series.

 

[SpenserAK]

Cosmoline and fluid film/wool wax both have their advantages, so from what I’ve come to learn, I’d say the best bet is using both in the areas of their strengths. Short version IMO, fluid film creeps and gets everywhere, like you said, so it’s good in tight spots with seams/etc, inside frame & other cavities, while cosmoline creates a more durable and perhaps better-in-general rust proofing, so it can be used over the main surfaces, although it takes more prep cleaning to be done properly. I actually just fluid filmed my whole truck today, including inside the frame, but have not used cosmoline yet. I do use a similar CRC product & boeshield T9 for my outboard & kicker, both of which work fantastically.

Not quite as salt-gnarly here, but I’m in the equal but opposite corner from you, in southeast AK. Same deal with winter - it doesn’t stay below freezing and is always wet. I know they sometimes use road treatment here, but luckily it seems that they often just use simple gravel. Vehicles definitely rust, but not like what you see from the rust belt proper.

My last XJ was losing its floor pans, and had a rotten unibody frame above the rear axle. My 80 has zero issues, fortunately. I do the whole truck before winter, and then touch up the rear half in spring before boat season starts. I don’t dunk the truck when I launch, but it’s extra protection.

Project Farm also has a couple great videos comparing all these products

 

[kw90surf]

The thing with Cosmoline is that you need to start with a clean, dry surface free of dirt, oil or other contaminants. There's an outfit in Alberta, and now Ontario, called Sublime Surfacing / Honey Seal that does a Cosmoline type undercoating, and they prep the underside of the cars by dry-ice blasting them (good YouTube rabbit hole for anyone interested). Basically, dry-ice blasting leaves you with an absolutely pristine surface, but dry ice blasting equipment is extremely expensive and getting dry ice blasting work done isn't cheap either. (There's also an outift called Rust Coaters Rust Coaters - Eau Claire WI Rust Proofing & Undercoating Center - http://www.rustcoaters.com/ in Wisconsin that does a Cosmoline based treatment). I considered taking a drive out to Ontario, but with the cost of fuel and the service itself costing $1300, I was looking at 5 days and about $2300 just to get this done. I figured I would give it my best shot at home for around $250 in materials and a lot of time and effort.


To start, I had to get the underside of the 80 clean. The red Rust Check applied last year had almost completely been washed off by this time, but the underside of the 80 was dirty and dusty and the engine bay was filthy. I started by driving the 80 up on ramps, popping the wheels and bumper corners off and pressure washing the underside and engine bay. I then followed up with some simple green in a spray bottle, some brushes and a follow-up with the pressure washer to get the oily grime off. From there, I donned my swim trunks, got on the creeper, and spent the entire day underneath and under the hood of the 80 with brushes, a bristle pad on the end of a drill, a foam cannon filled with dish soap, and the pressure washer.

 

[kw90surf]

Unfortunately, this 80 had some asphalt based undercoating applied at one point in its life, and it retains dirt like crazy. This is as clean as I was able to get it after pressure washing, 3 foam applications, pressure washing, tons to scrubbing (manual and motorized), and more pressure washing.

This is how I looked afterward:

Nasty. What isn't pictured is that I had the rear bumper and complete front fascia removed for this process, as well as the battery and battery boxes.

After this was done, I headed down to my Dad's shop to put it up on the hoist and continue the prep work. As mentioned, this truck had that asphalt undercoating applied, and it was patchy and gross in the wheel wells. I took an air-powered needle gun (every mariner's favourite tool) to the most suspect looking spots before I looked at putting anything overtop. It came off in some areas (as well as some of the factory sound deadening/rock guard) but in many areas was very much intact.

 

[kw90surf]

With this done as well as I could manage, I moved on to disassembly once again, removing the front and rear bumpers, mud flaps, and front fascia. I also pulled the battery, battery boxes, airbox, intake hoses, rad fan and shroud, and unbolted the washer reservoir, fuse box, and cruise motor so that I could work around them. With the truck fully dry, I tackled the remaining dirt that I had missed with the pressure washer with a set of bristle brushes and compressed air.

It'll never be this clean and pretty again...

 

[SpenserAK]

Is there not a factory-applied wheel well coating? I can almost guarantee nobody had done any treatments on my truck in the past, and mine has what appears similar to yours, at least the lighter colored stuff that doesn’t look too gnarly - maybe hard to tell from pictures, though. Definitely have seen the same on a variety of other vehicles as well.

 

[kw90surf]

The above pictures were pre-bristle and air blast.

After cleaning as best I could, I wrapped things like wiring harnesses, rubber hoses, anything I didn't want/didn't need to be rust-proofed in tin foil, and set to applying the Cosmoline to the engine bay. I used aerosol RP-342 on most of the bay, and CRC on the valve cover and intake manifold as they're more aesthetic and the CRC seemed to go on a little nicer.

No going back now...

 

[kw90surf]

Some skid plates, heat shields and engine bay parts I removed and cosmolined separately:

Here is the engine bay after everything had dried:

Onto the underside...

 

[kw90surf]

More brushing and blowing with compressed air:

Another example of an area that got missed with the pressure washer:

The underside as clean as I could get it and ready for Cosmoline (yeah, I didn't bother with the steering stabilizer):

 

[kw90surf]

The asphalt undercoating on the gas tank skid traps the dirt so bad

This truck had zero rust whatsoever when I bought it... Stinkin NS climate.

 

[kw90surf]

When it came time to apply the Cosmoline, I applied the "Industrial Strength" stuff to the underside. Cosmoline Direct suggests that you can thin the industrial strength stuff with mineral spirits prior to spraying, I chose to apply it at full strength from my Princess Auto undercoating gun to get the best protection I could. The CRC stuff on the Ford protected things awesome, this ended up at probably 3 or 4x the film thickness. With the regulator set to 80psi, the Cosmoline went on like paint. I set down a tarp under the 80 and masked everything of value in the immediate vicinity. I watched like a hawk for overspray mist, but it really didn't end up being an issue. The drips were nasty though, I recommend wearing a tyvek suit or hoodie you don't care about, rubber gloves, and a mask. If you get it in your hair or on your skin it's tough to get off.

I sprayed using the regular nozzle and it atomized pretty well, for inside the control arm brackets etc I used the 360* nozzle/extension. In doing the frame and axles, I used up most of the gallon of industrial strength stuff .

I got much of the rear floor and backside of the rockers in full strength. I took what was left of the gallon, thinned it with mineral spirits, then got the rest of the floor and underside areas that I'd missed.

After the first pass:

 

[kw90surf]

 

[kw90surf]

When it came to the wheel wells, I thought about re-applying another type of rock guard overtop of the factory coating plus the failing asphalt first, but finally decided I'd go straight to Cosmoline. The patchy appearance had been bothering me, and I was lucky enough that Cosmoline Direct had accidentally sent me a gallon of RP-342 "Black" instead of the "industrial strength" stuff (I got them on the phone and they sent me a gallon of the industrial strength stuff free of cost, shipped that day, and apologized for the inconvenience). So, I did the wheel wells in the black stuff and they look great now.

 

[kw90surf]

After it was dry the next day, I removed the flares and took a bristle brush and compressed air to the inside lip of the wheel wells. Once nice and clean up there, I applied full strength industrial grade cosmoline with a foam brush along the lips of the wheel wells.

 

[kw90surf]

With the flares off, I cleaned up the mounting hardware and brackets for them with the bristle brush and compressed air and cosmolined them, the bolts, and the little studs and nuts on the flares themselves (coated vs untouched):

So the thing with Cosmoline is once it dries, it no longer creeps. As such, unless you can apply it extremely thoroughly, it doesn't make the best *inner* panel rust preventative. In my testing of Cosmoline, i checked how it behaves when other rust preventatives are applied overtop. I found that Fluid Film will basically turn Cosmoline to liquid, and spraying Fluid Film overtop of dry Cosmoline means you can then take a rag and wipe the works of it off. But, red Rust Check doesn't seem to do the same. On the CRC that had fully set up on my Ford's rack, I sprayed Rust Check overtop and rubbed it with my fingers and it didn't seem to affect it much. And, weeks later when the Rust Check had washed off, the CRC was still there and very much intact. This was great news, as red Rust Check is the best-creeping inner panel protectant I'm aware of and I have tons of experience using it.

So, with the Cosmoline mostly set-up and dry 2 days later, I loaded some bulk red Rust Check in the undercoating gun and sprayed into every single frame hole with the spray nozzle and 360* extension. I tried to avoid the Cosmoline as much as possible, but I absolutely saturated the inside of the frame rails.

 

[kw90surf]

After thoroughly soaking the insides of the frame rails, I popped the rear seats out and pulled the carpet up, then took the fuel pump access panel off. I brushed and blew the dirt off the top of the tank and Cosmolined it:

Once the Cosmoline had set up on the top of the tank, I reached down with the plastic straw on an aerosol can of red Rust Check and sprayed all around the top of the fuel tank and in every direction under that access hatch.



From here, I cleaned every piece of hardware, latch, stopper, handle, and any other piece of metal on the body (door latches, hatch strut brackets, tailgate straps, etc. and applied Cosmoline to them. I also did the inside of the gas door, and the metal supports inside the rear bumper corners.

 

[kw90surf]

While I had the rear seats out (I took the front ones out too), I Cosmolined the feet of them and the latch mechanisms underneath, as well as the screws and bolt heads on them. I also Cosmolined the seat belt mounts/bolts and the dash supports and bolts.

 

[kw90surf]

 

[kw90surf]

With the Cosmoline set up in these areas too, I popped all of the plugs out that Rust Check had drilled when they first treated the 80 in 2019 and shot red Rust Check into all of the holes. This included each door, the front and rear parts of the rocker panels, the lower tailgate, and the upper hatch. I also popped the front corner lights out and sprayed copious amounts of Rust Check into the front fenders (between the outer and inner fenders. As well, I popped two bolts out of the radiator support and shot Rust Check in there, plus with the straw up through the drain holes. I also sprayed Rust Check along the bases of the rear quarter windows, inside the rear quarters (behind the interior panels), and along the rain gutters. And with the seats out, I peeled up the carpet and sprayed Rust Check along the floors and channels that run next to the rocker panels on the inside where water likes to collect.

 

[kw90surf]