Undercoating

Many people, especially in northern climates, will often have at least two cars: their pride and joy and their winter beater. Whether you drive a winter beater or a show car, your car will benefit from being undercoated with a rust-proofing material. Undercoating comes in a variety of forms and some forms protect better than others. Generally, any undercoating is better than none. The only cars not recommended for undercoating are show cars that are trailered to judging events and are never exposed to the weather.

Eventually, road salt catches up with winter-driven cars and, for some, no amount of body work can save them. For these winter beaters, a good oil spray (really any oil spray) really helps to squeeze a few more years of cheap service from these cars. Without more than anecdotal evidence, I will go out on a limb to say that the cost of even the cheapest annual undercoating job will pay back with at least an extra year of service. Usually, even one application early in the life of the car will pay back will may years of additional service.

Back in 1977, my Dad bought a brand new Pontiac Parisienne and he knew that it would last longer with undercoating. Not wanting to pay the seemingly exorbitant dealer price for this service, he decided to do this himself. He had a friend with a hoist and a compressor so he sprayed the under side of his car with some undercoating he bought from Canadian Tire. Thirty years later, the underside of this car is still in excellent condition. However, since he didn't have any wands to get inside the doors and the hood, these parts are rotten and it's probably not worth saving this car. Too bad, because the car still runs and drives great.

For your pride and joy, a good oil spray will help to protect it from the elements, even if you don't drive it on salted roads or when its raining. There is a potential for corrosion to occur just from the moisture in the air. If you only do a cheap undercoating job once in your car's lifetime, that investment will most certainly save you much more in rust repair jobs years down the road.

Professionally applied undercoating often comes with some sort of warranty. The warranty is there to protect the shop from your claim. If the warranty was there to protect you, it wouldn't have any exclusions and the shop would just take care of you because you had the receipt. When you hire someone to undercoat your car, find out what they are putting on and how they are doing it. Remember buy the undercoating service, don't buy the warranty!

Some things to consider:

• Whenever you put anything onto a surface, it will work better if the surface is clean to start off with. Ideally, your undercoating professional should power-wash the underside of your car before he starts. This will take time because a good shop will also let the car dry before it proceeds further.  Some cars have crevices that no amount of water can wash away the dirt.  You need to find this places yourself and remove this caked-on dirt.
• Most shops don't wash the underside of your car but you can do this yourself. You can take your garden hose and spray the undercarriage until the water washes off clean.
• Fresh surfaces (like on a brand-new car just driven off the lot) can be well protected by a tarry or waxy undercoating. We don't recommended this for cars with undersides that have started to rust. This heavy coating, sometimes known as sound-deadening, will not wash off even with autobahn road spray and is extremely resistant to abrasion from flying gravel.
• Older surfaces can be well protected with a light oily undercoating. The oily nature minimizes corrosion by penetrating rust and and sealing the metal from air and moisture. This protectant should be applied annually for the best results.
• Although some rust-proofing coatings that have the consistency of grease may appear to be thick, they will soak into rust when applied and the thicker consistency will allow them to adhere better and not wash off as quickly.  Sometimes the coating will even lift off loose rust.
• All undercoatings should be applied to the inside, hidden surfaces of your car like the rocker panels, doors, hoods, trunk lids, and wheel wells. The undercoater has a variety of thin wands that he can insert into the tightest of places. Often, holes must be drilled into the body for proper coverage. Don't bother doing this job yourself on your back in your driveway with a spray bomb.
• Try to avoid doing this job in the winter. If you can, try to schedule it during a dry spell in the summer or autumn so the undercoating can set without being washed off or blasted with winter road salt & sand.
• Undercoating shops often have promotions throughout the year, sometimes in the summer when business is slow, usually the in the fall. Often, they will put a coupon in the newspaper for you to clip and bring in.
• Find out exactly what the shop promises to rustproof. After getting the car back, inspect the work to make sure that you got what you paid for. Pay attention to the rust-prone areas of your car to ensure that they received adequate protection.
• If you're not sure where your car is prone to rust, join an internet forum dedicated to your vehicle and ask other owners what experience they've had. Make sure that the rust-prone areas get protection and don't depend on the rust-proofing shop to know (or care).

Some shops specialize in this service while others offer it as a sideline. There is no magic to undercoating a vehicle and it takes a bit of skill and experience to do it right. The important thing is that all vulnerable areas get a protective coating. Essentially, the cost of this service should not be much more than 1 hour of labour and a pail of material. The going price in the Niagara Region seems to be $80 - $130.

I had my wife's Sienna done a few years ago in the middle of winter (shortly after we bought it) by Ziebart for around $200. They were the only ones that included powerwashing as part of the standard application procedure.

Krown Rust Control, Rustblock, and Rust Check are other popular rustproofing franchises. Krown offers a CAA discount. All are light petroleum-based products that creep into crevices well. Being light, they should also be re-applied annually and the salt spray can wash the coating off by spring. Some people have found that these types of coatings drip so you need to be careful where you park for a few days. The quality of work can vary from shop to shop.

Many shops use rustproofing systems that do not appear to have a web presence of their own. I'm not sure why this would be the case other than perhaps the chemical is produced by a small mom & pop operation. These types of rustproofing system include Canadian Rust Control and Oilskin.

For touch-ups, the DIYer can apply rust-poofing with an aerosol spray. Krown, Rust Check, and Rust Stop offer their products through dealers, retailers, or on-line. WD-40 will also work and may be cheaper.

In 2008, Erie Collision offered an $80 undercoating job ($5 off with a newspaper coupon). I got my 2003 Impala undercoated there for this price but it took some planning as they only do this on weekends (Saturday & Sunday) mornings in early fall and on Saturdays later on. It's best to call ahead since they stop undercoating for the day when they figure that they won't have any more customers. The ramp is outside so be sure to pick a windless day so more of the undercoating ends up on your car and not on the brush on the other side of the road. I had to give my car a good wash when I got home as there was a lot of overspray. I also noticed that the underside of my wheels got a good coat of overspray, which probably means that my disc brakes were undercoated too.  I needed to get my Impala re-sprayed due to the inadequate work done by Erie Collision.

I also had to get a 2007 Dodge 3500 truck undercoated in 2008. Finlayson Tire does Oilskin undercoating and they had a $15 off coupon in the newspaper. The truck cost $130 (because of its size) and this work was done in one of the bays in their shop. Very little overspray and they cleaned the overspray off the glass when they were done. My 1973 Dodge Dart has an Oilskin sticker on a window and the undercarriage and doors are all still in excellent condition even though it was regularly winter-driven so I expect the truck to last a long time too. However, after a closer inspection, there were many obvious places (like the hood and front fenders) that were completely missed. The technician also appeared to go around the vehicle in one direction as many places were missed because he probably didn't look backwards as he was working. The moral is that the quality of the job depends on the skill and experience of the technician. Check the work afterwards to make sure that you got the protection that you were promised.

Lately, I've been getting my cars rust-proofed at the local Krown Rust shop.  The work appears to be thorough and the price is competitive.

Many independent shops provide undercoating work as well. Often, they will use an undercoating product (like Kleen-Flo Rustproofing or Dominion Sure Seal Anti-Corrosion Material) from their usual autoparts supplier. The important thing is to find a shop that has the skill and experience to apply the coating correctly. Being independent, these shops can offer a complete rustproofing job for around $80 since they don't have to pay for franchise fees and specialty products.