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Clear-Coat Paint Finishing Tips

For a show-stopping shine that helps your tractor stand out in a crowd, there’s nothing like a base coat of clear-coat finish. That’s because, unlike enamel, which must be buffed and polished to bring out a shine, a base coat of clear-coat finish gets its gloss from the clear coats that go over the paint coats, not from the paint itself.
But even though base coats of clear-coat finishes have been widely adopted by the auto industry, there are still plenty of questions among classic tractor enthusiasts concerning cost, difficulty of application, and its general advantages and disadvantages.
No harder to apply
Jim Seward, a tractor restorer from Wellman, Iowa, who also does bodywork and painting as part of his job at a local GM dealership, says it really isn’t any more difficult to apply a base coat of clear-coat finish than it is a single-stage enamel. It just takes an extra step when you switch from the color coat to the clear urethane.
“Another difference is that it can be a little more difficult to see where you’ve been with the clear coat . . . particularly on the second coat,” he explains. “It’s fairly easy on a flat surface like a car hood. But you realize how important good lighting is when you start putting a second coat on a contoured surface that’s already shiny.”
On the other hand, a base coat of clear-coat finish generally allows you to more easily correct mistakes than if you were using a solid coating, explains Gary Ledford, a paint technician from St. Joseph, Missouri. “If you get a run or imperfection in the color coat, you can just wait for it to dry, sand out the mistake, hit the area with another light coat of color, and clear-coat the entire panel. As long as the color coat is smooth and even, you’re ready to go on, since the gloss in the final coat comes from the clear coat.”
Leave time to dry
Ledford cautions, however, that you need to allow enough time for the reducer in the last color coat to completely evaporate before the clear coat goes on. This requires  at least an hour in most cases, but fewer than 24 hours. Otherwise, you can end up with what is referred to as solvent pop (the clear coat has bubbles formed by leftover reducer vapors trying to escape).
In most cases, two to three coats of base color are recommended, followed by a minimum of two coats of clear coat for both protection and shine.
A base coat of clear-coat finish can get rather expensive, which is the reason why many tractor restorers use two different types of finish on the same tractor. Generally, this amounts to a single-stage urethane. This is followed by a base coat of clear coat on the sheet metal.
“The cost of the paint depends on the type and grade of paint you use,” says Seward. “However, you can easily spend $100 a gallon on the clear coat alone, plus another $30 to $50 for the hardener it requires to work.
“The other drawback is that a base coat of clear-coat finish tends to show scratches more easily than a single-stage enamel,” he continues, noting that scratches in a clear coat tend to appear white. “So you wouldn’t want to just take a rag to a tractor that’s been collecting dust at a tractor show.”
Keeps its gloss intact
Still, Seward admits, a base coat of clear-coat finish has the potential to look just as shiny in a year as the day it was painted. Of course, that in itself can draw criticism from some collectors who insist that the tractor would never have been that glossy when it was new.
“I think, in the end, it comes down to cost, how you’re planning to display or show the tractor, and personal preference,” Seward concludes.
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