Rusting Ford truck in lawn at front of house

Inspecting for Rust Before Buying a Classic Car

Recently we put out an article on inspecting for problems before buying your next classic car.  One major issue is the signs of a previous accident. The other issue is inspecting for rust.

When it comes to rust, we cannot stress enough how much of a problem it can become during a restoration or even during simple repairs.

One major factor that determines a car or truck’s probability for corrosion is its geographical location. Rust problems are more common in humid climates and in areas where salt is used to keep ice off the streets during the winter. Areas such as the Upper Midwest and parts of the Northeast are especially known for rusting vehicles, largely because they suffer from both humidity and heavy road-salt use.

But just because you are looking for a classic car or truck in a dry climate like Arizona does not mean you are safe from rust. You need to consider the possibility that the decades-old vehicle you are going to inspect may have grown up in Michigan before finding its way to a drier climate.

A rusting panel on a silver car fender being held by a hand

Inspecting For Rust

The trick to finding a rust-free vehicle is knowing what to look for and where to look. There are different types of rust and different locations rust can occur that can make or break a deal.  Is the rust you discover repairable or is it a lost cause?

Being prepared to search for signs of rust is a huge advantage. Be sure to bring a small flashlight, a magnet, and a telescoping inspection mirror to help you check for rust or body filler.  A magnet will only stick to the metal in the fenders and body. It will not stick to body filler at all. If you only have a light magnetic pull, that means there is more filler than metal.

If there is rust (or signs of rust repair) it will be found around the wheel wells near the bottom of fenders and around the bottom of doors and door sills. There is also a good chance of rust in the floorboards and under the battery, so these areas should be the first place you inspect for rust.

Rust tends to start near the bottom of a car first which is problematic considering all the important parts that live under a vehicle. Because of this, we suggest checking the bottom of a car first. If you are concerned with an initial look under a vehicle, ask the seller to take the vehicle to a garage that has a lift so you can get a thorough look at the underside of the car or truck. Common rust spots include the frame rails, the wheel wells, the exhaust, the suspension and virtually any other underside components made of steel or metal.

You will also want to take an in-depth look inside the trunk. Pull up the carpeting the best you can to get a good look at the metal underneath for any signs of rust. Be sure to also check the inside of the doors and door sills along with metal around the front and back windshield. These are common areas for rust to hide.

Also, check the doors, both inside and out, along with areas around the windshield and rear glass. And another rust tip: If you see any exterior paint bubbling, it is an early sign of rust. This should be a key indicator to check under the car before you sign the papers.

Of course, you will need to inspect all the body panels for signs of damage from corrosion. Previous bodywork and paint jobs can often hide what is lurking below the paint. That is where a magnet can unveil body filler that was used to repair rust damage.

When you gently place your magnet against each panel, does it stick at the same rate all over the car? Sticking at different rates could indicate filler over rust or other body damage.

Now let us look at the different types of rust you are most likely to encounter when inspecting a classic car or truck to purchase.

Old blue Chevrolet truck with surface rust parked in a field

Surface Rust

Surprise, surprise… surface rust is rust that is only on the surface of the metal. This type of corrosion typically happens where the paint has become so thin that the metal has become exposed and moisture from the air has begun to do it dirty work.

If you see a little surface rust, it will be an issue you can overcome with some bodywork. It is certainly the least destructive type of rust in terms of ease of repair and the damage it causes.

If caught in time, it can easily be sanded away until you reach bare metal. The metal can then be primed and painted which will protect it from surface rust reappearing.

Pitted Metal

This type of rust has penetrated the metal and eaten it away leaving pits in the surface of the metal. The corrosion has not eaten all the way through but has certainly left scars. While this is not a great discovery, it can be corrected.

Once again, it will require sanding and brushing to get rid of. A wire brush is often used along with sanding to get the metal back to a bare state where it can be repainted. There may be some bodywork and filler needed to get the surface back to looking smooth.

Rusted trhu quiarter panel rusted thru by rear window on blue car with white top

Rusted Through

If there are signs or rust that has eaten completely through the metal, you may want to proceed with extreme caution. This is the most difficult type or rust to repair. In these cases, the only way to repair the damage is to replace the metal.

You might get luck and be able to replace a body panel, hood, or trunk lid, but beware that if the metal cannot be unbolted and replaced, you will need to cut out the damaged metal and replace it with new.

The roof, door sills, floors, etc. are areas of a classic car that will be exceedingly difficult and pricey to have replaced. In most cases, if you find this type of rust, there will be more that cannot be found upon immediate inspection. Be very wary of buying any type of vehicle in this condition. We would turn and run 99.9% of the time.

Finally

Rust can be the one issue that ruins even the most promising classic car. When we are shopping for a classic car or truck, we all are wishing to find the perfect specimen with zero traces of rust. The fact of the matter is that you will be hard pressed to find a vehicle that is 30 years old or more without any signs of corrosion. The cancer that rust can cause to your classic car’s metal work can make your car or truck a costly venture so taking your time inspecting for rust before buying will help you fully understand the scope of work you will be undertaking.

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