FINE FINISH

Defining the orifice size of a paint spray tip is crucial as it determines the flow rate of paint through the tip and significantly affects the quality and efficiency of the paint application. The orifice size is typically denoted by a number code found on the tip itself. Here's how you can understand and define it:

Numbering System: Paint spray tips are usually marked with a three or four-digit number. For example, a common code might be '517'.

First Digit(s): The first one or two digits usually represent the width of the spray pattern when the spray gun is held at a standard distance from the surface (usually 12 inches). The number represents the width in inches, but it's often half of the actual width. For example, in '517', '5' (when doubled) indicates a 10-inch-wide spray pattern.

Last Two Digits: These digits denote the size of the tip’s orifice in thousandths of an inch. So, in '517', the '17' means the orifice is 0.017 inches in diameter.

Type of Paint: Heavier, thicker paints require a larger orifice to pass through the tip, while thinner materials can be sprayed through smaller orifices.

Spraying Pressure: Higher pressure systems can often use a smaller orifice, as the paint is more forcibly expelled.

Desired Finish Quality: A smaller orifice can provide a finer finish but might require more passes for coverage.

Work Speed: A larger orifice allows for quicker coverage but might reduce finish quality and increase overspray.

Test Spray: Before starting a project, it’s advisable to test spray on a piece of scrap material to check the pattern and adjust as necessary.

Manufacturer's Guidelines: Always refer to the paint and spray equipment manufacturer’s guidelines to choose the appropriate orifice size for the specific paint and application.

Condition of Tip: A worn or damaged tip can alter the intended spray pattern and flow rate, affecting the finish quality.

Environmental Factors: Adjustments might be necessary depending on environmental factors like temperature and humidity, which can affect paint viscosity.