Just as the topic says.
I live in Toronto and the winters are pretty bad with the salt. Is it worth it to get my car drilled into to get it rust proofed or is it good enough to just spray the car underbody down? Anyone know how many holes are drilled and where on the coupe?
Decades ago, Honda (and other Japanese manufacturers) were sued because the cars they manufactured and sold in the U.S. had essentially no protection against corrosion. The panels were painted, and that was it. After settling with owners, Honda began to galvanize the sheet-metal panels that make up the bottom and sides of their vehicles. And that works provided the galvanized portion of panels remains intact. If that layer of protection is worn away from rocks and other road debris over time, the exposed metal will rust and rust quickly. This is a real problem where sand is combined with chemicals that melt snow.
So, to answer your question, yes, rust protection
works, but nothing will rust proof metal
. Fe plus NaCl and H2O = rust. The idea, then, is to keep sand, salt and other chemicals from coming in contact with exposed metal. Undercoating is a good start if done right
A good undercoating material is one that remains pliable. That's crucial. Once undercoating cracks, it acts to trap water, salt and other crud, which makes the problem worse than it would have been had the exposed area air dried. Also, because most outer panels are galvanized these days, most cars rust from the inside out. Consequently, it is crucial to ensure the inner
panels of doors, fenders, wheel wells, etc. are protected from exposure to corrosives. That's why various chemicals are sprayed inside doors, fenders and quarter panels; to seal the inner panels from corrosive chemicals that will invariably seep into those areas if a car is driven in salty shush.
But really good rust protection doesn't have to be expensive. In fact, one of the very best rust preventives is incredibly cheap: namely, used motor oil. Simply spraying oil on the underside of a car and into the inner panels works great. Repeat as necessary. It is an environmental mess, however, which is why no licensed business can legally do it. But a lot of people still do it because it works so well. If you are socially conscious (and you should be), you'll put something down to collect the overspray and depose of that sheeting in an environmentally responsible fashion. The alternative is to choose a reputable company to do the work and read their warranty carefully. Does it require you to return annually for inspections (it should), and if so, are the "touch ups" free? Does their warranty specifically state it covers any rust damage that occurs from the inside out? If not, find another service. How many years of protection are provided (and how long do you plan to keep your car)? Any car will remain rust free for three years, so a warranty should offer at least five years of protection. Ten years is better, of course. Does the warranty pass to the next owner? That, too, is important. Ask for references and the names of prior customers. Call them. Know what you're buying.
In summary, rust proofing is a myth, but it is possible to get additional years of rust prevention if you, or the service you choose, in consciencious.