Rustproofing
Rustproofing & Undercoating in Mississauga
Peel Region salts heavily from November through April, and salt brine gets everywhere a pressure washer can't. An annual oil treatment is the cheapest insurance you can buy on a car you plan to keep. From $199.
Where cars actually rust here
Not where people look. Visible surface rust on a door or a wheel arch is usually the last stage, not the first. What kills cars in Ontario is corrosion that starts inside closed sections — the insides of rocker panels, the bottoms of doors below the drain holes, the seams where the floor pan meets the sills, the subframe, and the brake and fuel lines running the length of the underbody.
Salt brine gets into those cavities as spray, then sits. Because they never fully dry out, corrosion runs year-round rather than only in winter. By the time it bubbles through paint on the outside, the metal underneath has usually been going for years.
Oil versus rubberised undercoating
Oil-based (what we use) creeps into seams and cavities, displaces moisture, and stays slightly wet so it self-heals when stone chips hit it. It needs redoing annually. That's the trade-off, and it's the right one for Ontario.
Rubberised or tar-based coatings form a hard shell. They look permanent and they're popular for exactly that reason, but when the shell cracks — and it does, from stone impact and flex — water gets underneath and is then sealed in against bare metal. A cracked rubberised undercoating actively accelerates rust. We don't apply it and we'd steer you away from anyone who leads with it.
What the job involves
Underbody wash and dry first — applying oil over caked salt just seals the salt against the metal. Then the car goes on the hoist and we spray the full underbody, into the rocker cavities through the factory access points, inside the doors and tailgate below the drain line, and around the subframe and suspension mounts. Takes about two hours, and the car will drip slightly for a day or two, which is normal.
When to book
Best: mid-October to mid-November, before the first salting.
Still worth it: any time. Mid-winter application over a properly washed underbody is better than waiting until next year.
Worth it or not?
Yes on anything you plan to keep past six or seven years, anything already out of warranty, and any pickup or older SUV — body-on-frame vehicles rot at the frame and it's expensive to fix.
Probably not on a two-year lease you're handing back, or a car you're selling next spring.
Pricing
| Vehicle | Price |
|---|---|
| Sedan / hatchback | $199 |
| SUV / crossover | $249 |
| Pickup / minivan / 3-row | $289 |
| With underbody salt wash Recommended | +$60 |
Confirm these against your actual rates before publishing.
Rustproofing questions
Does a new car need it?
Modern cars are galvanised and far better than they used to be, but galvanising protects panels, not seams, cavities or brake lines. A new car driven through Ontario winters still benefits — and starting in year one is much more effective than starting in year six after corrosion has already begun.
Does it have to be done every year?
Oil-based treatment, yes. It's designed to stay mobile and self-heal, which means it also gradually sheds. An annual application before winter is the whole model.
Will it smell?
Faintly, for a few days, mostly on start-up. It fades. The car will also drip a little for a day or two — park it somewhere you don't mind marking.
My car already has surface rust. Too late?
Depends how far it's gone. Surface rust on the underbody can be treated and slowed considerably. Anything that's perforated or flaking needs bodywork first — oil over rotten metal just hides it. We'll look and tell you honestly.
Protect it before the salt starts
October and November book out fast. Get in before the first salting rather than after.