The second coat of finish you apply to a project, after you have sanded the first coat smooth, is the most important coat because it provides the depth and sheen. Sometimes you can improve the depth with additional coats, but nothing equals the difference obtained from the first to the second.
Most important in this instruction is that you have to sand the first coat smooth to obtain the full effect. If you don’t sand this coat smooth, the roughness will telegraph through the second coat and reduce the depth and lower the sheen.
The surface will also feel rough. A further point to emphasize is that you can’t ever achieve the full effect of a finish with just one coat, no matter how thick you apply it. This is true for all finishes, even oil finishes.
