For those who don't know, I spent 20 years working in the auto body and paint industry. I was a professional painter, and a licensed collision repair technician. There's a reason the little blue car doesn't have any rust on it. I do my own rustproofing.
And growing up in Ottawa, Ontario, Canada I know about rusty cars. The city of Ottawa uses 180,000 tons of road salt every winter and it's devastating to the body of a vehicle. So, even back in the early 1980's before I got into the car business I was already researching how to stop a car from rusting.
There's only one product that really stops steel from rusting, and that's oil.
The problem is that there are many different types of oil. And there are different manufacturers of oils that are made specifically for vehicle rustproofing. Each one has their own formulation and chemical properties.
In Eastern Ontario, there have been three main "oil spray" choices over the past 30 years. The original was called "Oil Gard" and I used to use them a lot in the beginning. Then, shortly after that a better choice came along called "Rust Check" and at the time they seemed to have better trained guys doing the application. Half of the job of rustproofing your car is the guy doing the job. The other half is the product itself.
Then in the late 1980's "Krown Rust Protection" opened an outlet and I began getting my cars and my customer's cars sprayed there. Krown is a Canadian company and a Canadian product, but they do have some locations in the United States. If you aren't able to (or don't want to) follow these simple instructions to rustproof your own vehicle, I highly recommend the Krown product. For the $120 bucks or so it is the best money that you will ever spend on your car. Krown Locations
But I like to do these things myself. And, I like to save money (no way, you say!) so today, I gave the little blue car it's annual rustproofing. Yes, I have been doing this every year since 2006. And there is no rust on this car. And I took a few photos to show you how it's done. But first, let me tell you a little about rust.
Cars can have two different types of rust. There is "surface" rust, and there is "structural" rust. It's actually the same rust, but we call it different names because of where it appears. Surface rust is what you might see if you get a stone chip on your hood or a scratch that goes right through the paint. And after a couple of years it starts to bubble. It's unsightly, but it's not a structural problem. And surface rust takes many many years to become an actual rust hole.
Structural rust happens at seams and normally starts on the inside of a panel where you can't even see it. Even though you can't see it, it's the worst type of rust. Because the rust starts on the inside of the panel, by the time you see it, it has worked it's way from the inside to the outside, and now it's a rust hole!
Rocker panels and lower door seams are most often hit by structural rust.
This door bottom is only starting to rust through. It doesn't look as bad as the first picture, but it's actually rotten. Like I said, it's rusting from the inside out.
Okay, so by spraying oil inside the panels, we're going to stop it from rusting from the inside out, right? Right. Let's get to it and we'll show you how it's done!
I start at the front and work my way back.
This is the stuff we're going to use. Two cans ($8.00 each) is exactly enough to do the little blue car. Pretty much any vehicle larger than the little blue car is going to need three cans.
If you can't find the Krown product in your area, this is the stuff that I would use...
There is some mechanical work involved, but as a do-it-your-selfer you've probably got some hand tools around. I removed the headlights and the grille to have easier access to the rad support and the inside edge of the front fenders.
Now, the reason we can do the entire car with just two cans is because we're selective about where we spray the stuff. Cars almost always rust in the same places. Seams, and the lower six inches of any panel. So while many rustproofing places waste material on coating the entire inside of a panel, we're only going to target areas that are likely to rust.
You're looking for areas like this. Anywhere two pieces of metal are joined together.
Shock towers can be liberally coated. You want to use about half a can just doing the engine compartment and rad support structure.
Notice from the picture above how nice and clean the shock towers are. Even though I've been rustproofing them annually, I also power wash the engine compartment every couple of years to get rid of the accumulated crap, which also removes most of the rustproofing that had been applied over the years. I do this for two reasons. The first is purely aesthetic. It looks better when it's nice and clean under the hood! But it's also easier to work on if you have to do a tune up or oil change if all the greasy stuff is gone.
After you're done the engine compartment, you've got the hood open anyhow, so now you can do it.
Access holes are your friend when you're rustproofing! Simply use the directional spray tube that comes with your can of rustproofing, put it in the hole, and aim it towards the front edge seams. The product "creeps" over time, so if you miss a spot or two it's not a big deal. But again, you can be fairly liberal.
Before you put the headlights back in, you want to aim the directional tube on the inside lip of the front fenders. Again, only on the lip. No need to spray any product higher than about three inches from the bottom of the panel.
Don't forget to give a quick shot to the hood hinges!
Moving on to the front fenders. To do them properly, you should really take the wheels off. It's easier to get access to everything. You could probably cut corners to save time, but it really is easier to do a good job this way. because you're going to want to at least partially remove the front fender liner to access this inside of the lower fender, and with the little blue car in particular to get rid of the build up of crap that occurs at the rear edge of the fender.
Once you've got the wheel off, it's easier to access the inside of the fender. With the little blue car, you only need a phillips screwdriver, a 7mm socket, and a 10mm socket.
Notice the build up of mud and crap that is inside the lower fender where it meets the front door. You want to clean all of this out of there, and I even go so far as to remove the single 10mm bolt that holds the bottom of the fender on to the rocker panel pinchweld seam.
Nice and clean now.
Everywhere you see one of these access holes you want to pull the rubber plug out and liberally spray towards the lower seam. This will get all kids of rustproofing product inside the front of the rocker panel.
Then, you can spray the rest of the inside of the fender. Remember, you only need to do the lower 3 inches or so. While you're at it, and you have access to it, you can spray any seams of the inside of the wheelhouse and shock tower. Now, you can re-install the liner and put the wheel rim back on.
With the little blue car, it's easy to lift up the interior rocker panel scuff plate. This allows access to three small openings that you can liberally spray product into that will soak it's way down to the lower seams of the rocker panels. If you have a four door car, you do this for all four sections of the rocker panel.
Shops that do rustproofing, Krown and Rust Check included will not do a lot of this taking things apart. They have special wands that makes it easier for them to get material to some of these places, and they drill access holes where they need them. Plus they have to process a lot of cars each day and they would need to charge a lot more than $120 per car if they spend the time to take things apart. For them, it's a lot easier to drill a hole and put a plastic plug in the hole where necessary to cover the hole afterwards. In an ideal world, I don't really want any extra holes drilled in my car.
The doors are easy to rustproof. They already have two or three drain holes at the bottom so you can use these access holes to get the rustproofing product right where you need it.
Simply aim the directional nozzle where you want to spray it. Don't forget to do it in both directions!
And spray the door hinges while you're at it. Obviously, do the same procedure for all doors.
The rear quarter panels can be a bit tricky depending on the vehicle. On the little blue car (Chevy Aveo and Pontiac Wave) it is difficult to get material into the quarter panel dog leg section. This is a rust prone area on a lot of vehicles, and without drilling holes we need to get creative.
The front section of the rear quarter panel is called the "dog leg". It's a double walled panel, and a prime area for rust. So with the little blue car we have to partially remove the interior trim panel to gain access to the structure on the inside.
On the inside, you find access holes where you can spray the product. Still difficult, so again you want to get a lot of it in there. Better too much than not enough, and because the oil creeps, it will end up where it needs to be if you get enough of it in there.
Then, you can do the inside of the wheelhouse and the rear section of the rocker panels.
Easy to do with our car because there are access holes. Simply remove the rubber plug, and spray away! Don't forget to do the lip around the wheelhouse, and any other area where you see a seam.
You can then do the trunk or rear hatch. These are as easy as the doors and front hood. There should be access holes that easily allow you to get material where it needs to be. You're now done! Any left over material can be used to touch up some of the undercarriage, but modern cars are not nearly as prone to floor rust as they used to be back in the 80's and 90's. If you're at all unsure about getting the stuff in the right place, err on the side of caution and go ahead and spray it. It won't hurt to get it somewhere that it doesn't really need to be!
If you have a Krown location near you and you're at all worried about not getting the product where it needs to be, I would get your first application done there. Then, you can do subsequent annual applications yourself, knowing that there is already some of their product where it should be. Although, these guys are only human and they run production facilities. I have seen times where the pros have missed areas that need to be done, and I also know that areas like the lower inner fenders would have remained full of mud and crap because they don't take things apart like they would have needed to in our case.
And even if you never have plans on rustproofing your own car, at least you now know a little more about the procedure and hopefully that makes it easier for you to properly maintain your vehicle!
If you don't have a Krown location near you where you can buy spray cans, this is the stuff that I would use...