Rust Proof Your Car


By: Benjamin Preston

The automotive industry has come a long way when it comes to protecting its new vehicles from the ravages of rust. Better galvanizing and preventative coatings have, said Mike Quincy, an automotive content specialist at Consumer Reports, caused rust to nearly disappear from the list of reliability issues that once plagued even newer cars.

But anyone who has ever owned an old car or truck knows that rust, or the potential for it, lurks in all of a vehicle’s dark corners and crevices. What starts as a light orange frost one season can turn into bubbling paint another, flakes another, then, finally, the dreaded assault of what many refer to as “cancer” – holes.

Having purchased an Arizona-fresh 1987 Subaru GL wagon last year, I knew that if I didn’t do something – anything – to prevent the humid, salty air of summer and the salty springtime road film that inevitably finds its way into everything in New York City, that the wheel wells on this thin-skinned Japanese car would quickly come to resemble a piece of burnt toast with large, ragged bites taken out of it.

There are many ways to keep a vehicle from rusting – keeping the paint touched up, washing the undercarriage frequently and avoiding driving on salt-covered roads or in any kind of moist weather. But for tips on further prevention, I explored the nearly endless array of options available on the internet. Some products were just for the wheel wells and flat undercarriage parts. Others could be sprayed inside doors and other cavities where corrosion-causing moisture might collect.

Finding the “best” one is a nearly impossible task, as there are so many options.

The guy in one YouTube video shouts the merits of spraying rubberized undercoating beneath his ’69 Plymouth Roadrunner. But others online say that rubberized undercoating can cause problems if there are any gaps at all. Moisture and salt can build up in cracks and damage the metal underneath. The same can be said of factory-applied rubberized undercoating. I’ve personally seen unnoticed cracks in undercoating gain attention only after becoming gaping rust holes.

Some rust-preventative paints are, as advertised, hard as a rock when they cure. But after using POR-15 on an old Toyota several years ago, I learned that unless it was applied absolutely perfectly, it would peel in places, leaving patches of metal open to corrosion. Painted-over nuts and bolts disturbed the integrity of the paint’s surface when they were removed — another drawback.

So I kept searching, and found that many people recommended wax or oil-based chemicals that could be sprayed into tight corners every year and allowed to drip down through doors and inside body panels. Eastwood was one of the ones noted as an effective wax product, and Krown, an oil-based spray inhibitor available in Canada, was frequently lauded by the chorus of unqualified internet commenters. Not many among this electronic peanut gallery seemed to like Ziebart, which makes a harder waxy undercoating.

Further digging revealed that many school districts in Upstate New York use Carwell, the American version of Krown, on bus fleets. The United States Marine Corps Corrosion Prevention and Control program uses it on a number of its truck and equipment fleets, albeit in conjunction with other products. If it worked well on heavily used fleet vehicles operating in a part of the country where road salt can make a car’s body panels resemble Swiss cheese in only a few years, I reasoned that it might be just the stuff I was looking for to protect my “new” Subaru from the ignoble fate suffered by other old cars I’ve owned.

Peter Marini, head mechanic of the Fairport Central School District, near Rochester, N.Y., said that before the district’s entire fleet was being serviced with Carwell’s spray-on rust inhibitor every year, his shop had to repair wheel openings, stair wells and doors on buses on a regular basis.

“When I started here, we had just started doing buses with the Carwell product,” he said. “On half the fleet, we’d be replacing panels all the time. To date, I don’t do any rust repair, and we’re talking 16 years.”

Tom Delavan, Carwell’s fleet manager, said the company serviced about 115 buses for Fairport annually, as well as buses for other school districts, fire trucks and military vehicles at Army and Marine Corps units around the region. Carwell’s largest fleet, he said, consisted of about 120 buses at the Rush Henrietta School District, located not far from Fairport.

“The service life for a bus is 10 to 11 years,” said Kurt Gerould, Rush Henrietta’s head mechanic, who has had Carwell treat the buses in his charge for years. “But in 10 to 11 years, we don’t have to replace body panels and parts because they don’t rot out the way they used to. It’s been a cost savings just in that.”

Mr. Delavan said Carwell serviced about 3,000 vehicles per year in its retail service bays, which are located near Buffalo, N.Y. He said the company also treated about 3,300 fleet vehicles with its mobile units – an armada of trucks and vans equipped with portable air compressors, tanks of rust inhibitor and two- to three-man crews. He said they serviced roughly 200 school districts, 150 highway departments, 16 fire departments and several equipment rental operations, too.

The rest of the company’s business comes from direct sales of its rust inhibitor products, and from application equipment employees fabricate at the shop in Buffalo. Mr. Delavan said those products were usually bought by classic car owners, “regular” car owners, fire departments; anyone who needed to keep a vehicle from rusting.

Bernard Friend, the operations manager of the the Marine Corps’ corrosion control program, said that although the Corps does use Carwell’s T32 rust inhibitor on a number of its trucks and other “assets,” the chemical is part of a larger rust prevention strategy designed to reduce equipment costs by making things last longer. The suite of products the Marine Corps uses includes paints, primers, corrosion inhibitors, desiccants, film coatings, polyurethane coatings, and various tarpaulins and covers.

“There’s a tremendous laundry list of products we apply to equipment,” he said, adding that the Marine Corps has a process for testing the effectiveness of different products before they’re put into use. “Paint protects a surface more than any inhibitor could, but the inhibitors get to the seams and crevices, and on removable parts.”

Along with products from 3M, Sherwin Williams, Hentzen Coatings and others, Mr. Friend said Carwell’s T-32 was an effective rust inhibitor.

Armed with all of this information, I decided that, for me personally, the best course of action concerning my rust-prone Japanese wagon would be applying Carwell’s inhibitors at home. The problem – Mr. Delavan and the online opinionosphere were in agreement about this – was that it wouldn’t do any good if improperly applied.

“This product is only as good as its application,” he said. “If you’re not putting it where you need to put it – inside doors and rockers and such – it’s not going to be as effective.”

Unfortunately for me – and for anyone who lives in a place where the highway department uses salt on the roads in the winter, or places further east and south, where the air is salty and humid – Carwell’s retail locations are centered around Buffalo and Syracuse. That is not at all close to many places – the entire Northeast, the Midwest, the Atlantic and Gulf Coasts and mountainous areas all around the country – where rust is a problem.

And the company’s mobile trucks don’t make house calls – they service fleets.

The only thing to do, I reasoned, was to become a trained technician so that I could spread the knowledge of how to properly treat a vehicle to those who lacked the time, money or wherewithal to drive to Upstate New York. So I took one for the team and drove seven hours there and seven back in one day, spending several hours with Mr. Delavan learning how their product works and how to apply it.

Ken Wild, Carwell’s general manager, explained that T-32, which has been deemed by the authorities as environmentally safe, is basically a penetrating oil. Once sprayed onto a piece of metal, it creeps into areas that haven’t yet been treated, oozing into corners and crevices, displacing moisture and salt, and working its way around existing rust to bond with unoxidized metal.

Mr. Delavan showed me how to do the spraying, which was pretty straightforward. Here’s how it’s done:

Suit up in clothing you don’t mind getting dirty. T-32 is oily, and gets all over everything. It’s a good idea to wear a dust mask to keep vapor out of your nose and mouth. Safety glasses, although advisable, make it difficult to when spray gets on them (if you get this stuff in your eyes, it blurs your vision until you blink the oiliness away).

Open the hood, tailgate or trunk lid and all the doors.

Drill small holes in the jamb side of each door, and in the door sills for access inside the rocker panels.

Use a long wand attachment to spray inside the doors and rocker panels, making sure you see “smoke” (atomized oil) start to billow from cracks on the other side of the door, tailgate or panel. Spray the seams around all the doors and tailgate/trunk lid– Carwell says T-32 will creep between them. Make sure to spray under the fuel cap access door, if the car is equipped with one.

Spray inside the wheel wells: Make sure to get around the edges, and up where the shocks or struts are mounted.

Use a flexible hose attachment to spray inside the spaces in the bottom of the hood, watching for smoke to emerge from the opposite ends of where you’re spraying. There are many places for moisture to collect in there.

Spray around the sides of the engine compartment, behind the lights. Don’t worry about getting it on wires, as Carwell says it will seep beneath the wire casings to prevent corrosion. Be sure NOT to get it onto engine drive belts and tires, as it is very slippery and, as Mr. Delavan said, would “make the belts pop right off.”

Pop plastic plugs in all of the holes you have drilled.

Raise the car and begin spraying the bottom. Start with all of the holes and cracks that can be seen; anyplace where moisture could hide. Move from the front to the back and systematically shoot every hole. Then, start back at the front and spray the entire bottom of the car, moving toward the back.

Then you’re essentially done. The outside of the car gets washed (to get rid of the oily residue). The car will drip for a few days, so it’s probably not a good idea to park it in your garage or driveway, but Mr. Gerould says that even though his dripping buses cause a mess, the stuff washes away after some wet weather passes through. (Carwell’s own facility, which never gets a reprieve, is perpetually slippery).

Whether or not my old Subaru will rust after a winter driving on salty roads remains to be seen, but the locks and parking brake cables, which were a little stodgy after 27 years in the Arizona desert, are already working a lot better. It’s basically as if someone PB-Blaster-ed my whole car.

The downside, other than the mess, is that Carwell recommends applying T-32 every year. At a retail location, that costs a little over $100 for a normal-sized car. It’s cheaper to do it yourself, but you need an air compressor and some sort of spray gun. Mr. Delavan said that a $20 paint sprayer from Harbor Freight Tools would work fine, but recommended Carwell’s more complicated (and accordingly more pricey, at nearly $500) sprayer pot for more thorough application to the insides of doors and rockers and inside cab corners and such.

The bottom line of all of this is that rust prevention saves money and time in the long run. Everyone I talked with – bus mechanics, the Marine Corps rust prevention people and even a guy who owns a yard full of rusty Subaru parts in Connecticut (and first got me thinking about this) said that keeping rust at bay will make your machine last longer, whatever it is.

Of course, Mr. Quincy’s practical advice for those who wish to avoid dealing with the headache and expense of rust repair is simple: Don’t buy rusty cars and don’t drive old cars during the winter. Easy, right?

Atmospheric Corrosion “to Salt or Not to Salt” – that is the Question

REPORT #1 – March-April, 2002

It appears that an important change or trend is underway in the approach to the application of ice melting chemicals on our roads and streets. We all know how destructive traditional salts [calcium or sodium chloride] are to the metal parts of automobiles and concrete structures. In addition, the hundreds of thousands of tons spread across our highways have caused great concerns about environmental pollution. The Federal Government is considering classifying these traditional salts as “toxic” which is driving various groups to look for better methods and leads to a controversy between safety and environmental groups.

Since 1996, the City of Kamloops, BC and the Insurance Corporation of British Columbia [ICBC] have been carrying out a joint study of the use of magnesium chloride to replace the sodium and calcium salts. Magnesium Chloride is applied as a liquid via tank trucks similar to dust suppression watering and in some hilly areas in Kamloops there are buried spray systems that are automatically actuated when icing conditions are imminent.

The controls are becoming somewhat sophisticated by the use of atmospheric and buried temperature sensors and weather monitoring stations. Much of the collected data is transmitted to St. Louis, MO. where satellite monitoring of North American weather occurs and warnings are communicated to alert of snow and/or icing conditions about to happen. The application of Magnesium Chloride begins before the slippery conditions happen. This chemical is more effective in preventing a bond of ice to the pavement and it melts or softens the ice to allow sand to stay in place for better grip. Magnesium Chloride is less corrosive than the other salts and is more environmentally friendly.

A major problem is that it is much more expensive than the other salts [about $1200 / ton vs. $60 / ton] hence the efforts to use it effectively. Another unattractive issue is that the residue dripping from your car leaves an inky black puddle that stains clothing or foot wear, but then the other salts stain also. The black puddles wash away very readily with a garden hose in warmer weather, and clothing stains are removed via washing or dry cleaning.

ICBC states that between 1997 and 2000 there have been $2.5 million fewer accident claims in Kamloops! Apparently a number of other B.C. communities are now using Magnesium Chloride as well.

Some of the Contractors that maintain our provincial highways are also adding Magnesium Chloride to their spreader trucks to improve their operations. These spreader trucks are often equipped with on board computer controlled spreaders to ensure that proper applications occur. Also remote weather monitoring stations assist in determining when and where melters are needed.

All of these activities are welcome improvements to reduce corrosion problems but with every benefit there is a down side and one of those is that communities like Godrich, Ontario will be producing less sodium/calcium chloride. I believe that the Saskatchewan potash industry also produces lots of salt. But then change is usually not easy!

Any information about the efforts or concerns in other parts of Canada would be most welcome.

Bob Chambers
Corrosion Department

REPORT #2 – May 10, 2002

I have accumulated lots of data on ice and snow control which usually involves the use of corrosive chemicals. Much research has been done on this subject over the last 10 years in Finland , Sweden , Canada and the USA . Without drowning everyone with many pages of data I think it is fair to say that there is no magic elixir or system that suits all.

A system using products with a proactive anti icing or de icing program in Vancouver would likely be totally wrong for Edmonton or Toronto . Weather conditions across Canada are as we all know most variable.

I will try to summarize the different types of chemicals typically used and why well managed programs have an impact on safety,corrosion and the environment.

Calcium Chloride. [ CaCl2 ]. – is extracted from natural brines from deep wells around the Great Lakes and is produced along with soda ash another industrial product.

Sodium Chloride. [ NaCl ]. – is produced by mining, evaporation of sea water or vacuum processing of brine solutions.

Magnesium Chloride. [ MgCl2 ]. – is produced from Great Lakes brine solutions and often has corrosion inhibitors added.

Calcium Magnesium Acetate. [ CaMg2{CH3COO}2 ]6. – is produced by reacting acetic acid with limestone.

Potassium Acetate. [ KC2H3O2 ] . – is produced by reacting acetic acid with potassium carbonate also known as potash.

Why so many different products?

Temperatures of the road surfaces, air temperature, type of precipitation, traffic volume and a host of other variables will dictate the type of product or blends of such and their application rates. All of these factors must be evaluated to implement an effective ice control program. Control of the concentration of the chemical mix is vital and has a direct bearing on corrosion rates also. Often abrasive material is combined with the ice melters and they will precipitate a corrosion problem by chipping or abrading the automobile surfaces. Environmental concerns must also be addressed and costs of cleanup after winter have to be factored in. There are vast differences in the costs of the chemicals which drives the users to effectively apply the products. Training and experience of the operators also has a direct effect on how good the program is. Insurance companies are always interested in any efforts to make the roads safer by reducing the winter hazards and of course political considerations can also influence the effectiveness of any program.

It is stated that Sodium Chloride and Calcium Chloride causes corrosion, and that Magnesium Chloride is less corrosive. Potassium Acetate and Calcium Magnesium Acetate do not corrode but have greater environmental impact than the afore mention products. All products have environmental impacts to varying degrees.

Ice melting abilities vary with each product and will often dictate what product or blends must be used to be effective.

Professionally managed proactive anti icing programs are a definite trend and there will undoubtedly be lots of learning experiences to come.

It does not appear that a purely non corrosive environmentally friendly anti icing product is apt to be in general use any time soon.

Bob Chambers
Corrosion Department

REPORT #3 – Nov 27, 2002

It has been reported that the trial applications of magnesium chloride via an automatic spray system in Kamloops , BC has had ongoing glitches. It was not intended to spray this product on cars stopped at traffic lights. There are 125 sprinkler heads installed at the Hillside intersection which were intended to be fully automated. However, because of these problems the system was operated manually over the past winter. So far this season has been very mild and anti-icing activities have not yet been required. The system is expected to be operating fully automated by early 2003.

It has also been reported that a product used as road dust suppresant has been banned in Ontario due to environmental concerns. It was suposedly “not corrosive” but we will not likely hear anything further on this one. It is called ” Dombind “, and is produced by a corrugating medium producer [ Norampac ]. It is made from waste liquor and the concern is that dioxins [ a potential carcinogen ] could build up in the long term.

Bob Chambers
Corrosion Department