Arguments in favor of a Dedicated Primer Gun

However, there are some painting experts who argue eloquently in favor of using a second spray gun for nothing but primer – and, as with their opponents who hold that “primer guns” are an unnecessary expense, they base their argument on the considerable expense of a new spray gun.

Since a brand new gun costs in the $300 to $400 range, these painters argue, it is senseless to risk it by spraying substances more likely to cause problems, clogging, or complete ruin of the device when you can purchase a cheaper, used gun that will represent a much smaller monetary loss if the primer destroys it.

A spray gun used for primer is somewhat more likely than a paint-only gun to become clogged and ultimately ruined by the substances being sprayed through it. This is especially true if any kind of texturing additive is used in the primer – for example, if it is thick, solid-rich high build primer intended to smooth over the last few ripples and scratches of a prepared bare metal surface, there is a much higher risk of some of that material lodging in the inner workings than if a smooth, freely-flowing paint is used.

This high concentration of solids is almost always found in primer, due to its role in surfacing the car. Paints, on the other hand, are usually purely liquid, assuming they have been correctly mixed – even texturing agent, which produces a textured surface on paint that allows it to blend into a vinyl top, may rely on chemical action to create the texture, and is rarely used in any case.

Shooting high-build primer, in short, is much riskier than shooting paint for most painters. A good argument in favor of buying a second spray gun for primer is that it is unwise to risk a $350 paint gun when you can acquire a used, secondhand sprayer for primer at a fraction of that cost. If the cheap, backup spray gun becomes hopelessly clogged with solidified primer, then it is a far lesser loss than if your expensive new spray gun is ruined beyond repair and you are forced to buy another.