Block-sanding the vehicle is the critical step that makes the car's panels look straight. The reason a block is used is to distribute the hand's pressure evenly across the panel. Sanding without a block will leave finger grooves in the panel, which in turn will cause the panel to look wavy once painted. Blocking begins with sandpaper as course as 180-grit to knock any high spots off the filler, then by using progressively finer paper, the panels become smooth and straight. The best body men don't look at a panel to judge straightness during the block-sanding phase, they feel for straightness. The adage of "if you can feel it, it will show in the paint" holds true. a good bodyman will run his hand down a panel to feel for the slightest imperfection, correcting it before paint is applied.

There are some other tricks to block-sanding, such as sanding in diagonal strokes and using a metal ruler or paint stirrer wrapped in sandpaper to follow body contours. Low spots can be detected by misting the panel with dark colored spray paint or dry guide coat and blocking lightly. The places that remain the color of the spray paint are the low spots and need to be filled.

Regardless, plan on spending lots of time on this step of the paint and bodywork process. The more time spent blocking, the straighter the car will appear when it comes out of the booth wearing fresh paint.

Now that we've completed the rust removal, metal work, and gotten the body straight with filler and many hours of sanding, we're ready for paint. But we can't just roll it into the booth and start shooting; first we must make sure we have the proper equipment and make some decisions about the type of paint, not to mention primer, which will be used to cover our car. First and foremost we must understand the main function of paint is to protect the underlying metal and looking pretty is secondary. Before the paint is applied, however, the car must be primed with a quality primer and blocked once again. This step of priming is to seal the car and its bodywork from the paint above, ensuring that the paint will have a smooth, consistent surface to bond to and the different colors of filler, primer, and metal won't cause any color variations when the paint is applied. J.D. prefers a two-part, urethane surfacer for final priming.

When choosing paint, a compromise must usually be reached between the quality desired and budgetary restraints. Most modern paints do a decent job of protecting the underlying metal, but cheaper paints can be less tolerant to sun, fading quickly if the car sits outside for any length of time. Today's paints can be divided into two basic categories: single stage and base/clear. The single stage paint system, like its name, is a process in which the color is applied in one step. All of the paints ultraviolet protection, pigment, and additives are mixed in one can and applied to the car. This method works well and is still used extensively, though primarily on budget paint jobs. The latest advances in paint technology have resulted in a two-part or base/clear process that first applies the color to the car (base coat), which is followed by a clear, protective second coat of paint (clearcoat). All new cars are painted in base/clear as it offers distinct advantages, such as protecting the pigment by adding ultraviolet blockers in the clearcoat. Repairs of base/clear paint jobs can also be easier than single stage paint systems. The biggest advantage, however, of a base/clear paint job is the luster. By clearcoating over the color, the paint job looks thicker and has a shinier appearance than most single stage paints. Also, rock chips and door dings are usually less apparent in base/clear paint jobs as the colored base coat is usually left intact.

Regardless of the type of paint you choose, remember you get what you pay for. More expensive paints will last longer and retain their pigment better than cheaper counterparts. Once the choice is made, the only thing left is to apply the paint, and for that we need the proper equipment.