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Fit and Finish: Why It’s Important

Have you ever looked at a car and knew right away that it was in an accident? Maybe the paint was different on one body panel, or the door wouldn’t shut right. While fit and finish may seem cosmetic, this poor repair quality is more than skin deep. If care isn’t taken to get everything to match during a collision repair, your car could have major problems down the road. Here’s how body technicians bring cars back to factory specs, so it looks right and works right.

The Effects of Poor Fit and Finish

If you’ve ever bought a used car, you’ve looked for a good fit and finish, even if you didn’t realize it. When inspecting a car, you probably asked yourself these questions:

– Do the body panels fit together?
– Does the paint match?
– Are there rattles when driving down the road?
– Do all the doors and windows open and close easily?

There’s more to this than just appearance. Misaligned panels can create gaps between seals, letting water and air into the vehicle. In severe cases, water will drip down the windows in a car wash or loud whistling can occur while driving on the highway. Smaller leaks may not be as dramatic, but condensation can lead to wet, moldy carpets.

Poor fit and finish can also be a red flag for poor quality work elsewhere. If the previous owner cut corners on appearance, they probably did the same with critical components like the frame, airbags and seat belts. If you have a car with these problems, it’s going to be harder to sell.

Fit and Finish at the Factory

Some of you are old enough to remember the days when you’d want a “Wednesday” car. If a car was built at the start or end of the week, the workers would be sloppy, and the car wouldn’t be put together as well. Today, that’s not a concern due to the increasing use of robots to both assemble and test components on the factory line.

To raise quality standards throughout production, automakers have partnered with the National Institute for Standards and Technology (NIST) to develop better ways to measure components and get better fitment. These companies also brought in meteorologists to work on industrial processes. These measurement experts make sure everything is in place.

Using robots for assembly helps, but it was the use of automated quality control that has really improved fit quality. Quality control robots use lasers to measure the vehicle and compare it with a CAD drawing. If the panel position is out of spec even slightly, it can be detected and flagged for adjustment.

As a result, American automakers have shifted from a margin of error of 5-6 mm (¼ inch) in the 1990s down to 2 mm (less than 1/10th of an inch) during manufacturing.

Getting Quality Fit at the Body Shop

Body technicians use a combination of classic and modern tools to duplicate or exceed factory assembly standards. This starts with panel gap gauges. These feeler gauges slide into spaces between panels, letting the technician check gaps without marring the paint. This gets each panel in exactly the right position.

Larger tools like frame straightening machines use the same laser sensors found on the factory floor. Instead of comparing the vehicle with a complete design document, measurements are taken and compared to a long list of factory specifications. Out of spec measurements can clue the technician in on hidden problems with the frame and suspension.

Paint Matching

Aftermarket paint companies have labs that create recipes to duplicate factory paint finishes. Painters use these recipes to mix color agents, pearls and other materials to get an exact match. We use the Spies Hecker paint system, which has more OEM certifications than any other system on the market.

Over the years, paints will fade, so a true factory-matched paint job will look different from adjacent panels. To avoid this, the shop technician mixing the paint will vary the color slightly and spray samples that they can compare with the car’s undamaged panels. Once they have an exact match, they can apply the paint to the car. To further hide differences, paint is gradually faded out away from the repair. When done right, a repaired panel should be indistinguishable from undamaged areas.

Get Your Car Fixed Right the First Time

When you need auto body repair, the choice is simple: take your car to Merton Auto Body. We’ve helped customers in Lake Country for over 70 years, and we keep up with the latest technologies by maintaining ASE and I-CAR Gold Class certifications. Worried it will take too long to get a good repair? We have a short keys-to-keys time and we have an on-staff appraiser to get work approved by your insurance company. Our shop is between Lisbon and North Lake, just a short distance from Pewaukee and Hartland.