Gravity Feed Spray Guns

When deciding upon a spray gun you have a choice between gravity feed and conventional feed. It is in reality a misnomer to call a conventional feed spray gun “siphon feed” because “siphon feed” has a precise meaning. However, using the term “siphon feed” often communicates “cup on the bottom” to many experts where as “gravity feed” generally means “cup on top”. This article talks about the differences between the two designs.

Spray guns all have one thing in common – the atomization of material at the tip where the paint leaves the fluid nozzle. There are two passageways in a spray gun – one for air and one for fluid. Atomization is attained by a vacuum formed by the air rushing past the fluid passage while drawing the fluid into the air stream. At this time, air is combined with fluid and a spray mist ejects from the nozzle.

In order to generate adequate atomization, the paint has to be either drawn up from below the gun (conventional feed) or fed from the top down into the nozzle (gravity feed). In order to generate sufficient atomization with siphon feed, greater air pressure must be employed in order to obtain a strong enough vacuum to pull the fluid up the feeding tube from below. The requirement for greater air pressure in siphon feed guns is the main limitation for their use in HVLP systems. It is much more difficult to keep low air pressure and develop adequate vacuum.

It is clear that gravity feed overcomes this constraint and a smaller amount of air pressure is necessary to atomize the paint.

Conventional feed guns were the earliest to be frequently used in autobody repair. Until the introduction of HVLP (high volume low pressure), all conventional feed spray guns were siphon feed. In the 1980’s gravity feed spray guns came into wide use and their reputation has overtaken the use of conventional feed. Painter’s have begun to favor them over conventional feed guns and the arrival of HVLP as a requirement by environmental laws made gravity feed the natural choice.

Gravity feed spray guns usually use a paint container on top of the spray gun, and the paint is fed by its own weight and atmospheric pressure, by gravity, into the spray gun. Gravity feed spray guns can minimize your job time in half with the help of the HVLV gravity feed spray gun. This gravity feed spray gun will come with totally adjustable spray and fluid controls to give you wonderful perfection. Perfect for spraying enamel, lacquer, stain, primer and urethane with professional results, gravity feed spray guns feature adjustable fluid and spray controls for precision painting operations.

Gravity feed would allow spraying of heavy materials, uses all of the material in the cup and is gaining wide acceptance in automotive refinishing. By being able to use heavier latex paints, they are also perfect for around the home uses like painting decks, fences and other small to medium sized pieces.. Further, gravity feed calls for less air pressure for operation than the suction or “siphon” feed method. The use of liners allows for simple maintanence of the equipment after use and provides for upside-down spraying. These spray guns optimize the amount of material used, saving you money.

Spraying with less air pressure has the advantages of less overspray, less waste and greater control for the painter. These are the reasons why painters have been shifting from conventional feed to gravity feed guns.