Sagola Spray Gun Terminology
Sagola spray gun terminology
Air Cap: Found on the outside of the spray gun nozzle. It determines the quality of the finish of the paint by directing compressed air against the paint to form and shape the spray pattern
Atomization: Refers to breaking bonds, in this case forming tiny droplets of paint to aid the paint spraying process. It is caused by paint mixing violently in an air stream or by a sudden drop of pressure.
Baking: Using heat to cure and dry paint to speed up the automotive refinishing process. It is also known as ‘force drying’. It minimises the risk of the paint becoming contaminated by dust particles during air drying.
Basecoat: The coloured paint of the vehicle. This is usually finished with a clearcoat that provides a gloss or matt finish as well as providing UV protection.
Binder: Refers to the actual film forming component of the paint. As the name suggests, it binds the pigments of the paint together.
Blending: A paint application technique that insures colour consistency.
Blistering: Where air bubbles or water droplets have formed in the paint film. This can happen due to the layer of paint being laid too thickly or the outer layer of paint drying before the solvents underneath can evaporate.
Buffing Compound: A smooth paste containing a very fine abrasive, used to remove small imperfections on the vehicle’s paint surface. It can be used to remove light scratches and polish a topcoat.
Clearcoat: Paint containing no colour pigments, or only transparent pigments that give a certain finish such as gloss or matt. Usually sprayed over the basecoat.
Colour Match: Often used in body repairs, matching the original vehicle colour to the new replacement paint colour.
Compounding: The technique used when applying an abrasive such as a buffing compound, either by hand or by machine. The result is to smooth and enhance the gloss of the topcoat.
Double Headed – This refers to the application of two coats of paint, the first layer is applied and the second follows straight after with no flash off in between. This technique requires a longer flash of before baking.
Fish Eyes: A mottled finish in the paint, where air bubbles have caused small craters to appear. They are caused by improper surface cleaning or preparation. Silicone is often the most common cause of fish eyes.
Flake Orientation: When a metallic or pearlescent paint is used, it contains flake shaped pigments. The orientation and distribution of these flakes determine the final colour and visual appearance of the bodywork. It is important to select the correct flake when mixing the colour formula as well as taking care when applying to achieve a good colour match and appearance.
Flash Point: The lowest temperature at which there is enough flammable vapour to ignite when a spark or naked flame is applied.
Flash Time: Is the necessary waiting time required between spraying coats of paint to allow the first coat to dry.
Fluid Needle: The part of the spray gun that opens and closes directing the paint into the airstream.
Force Dry: Using heat to accelerate the paint drying process (see Baking)
Gloss: The top coat applied to reflect light, giving a smooth and shiny appearance.
Gravity-fed Spray Gun: A paint gun that uses a paint cup positioned on top of the gun that is used to feed the paint supply down into the gun using gravity.
Grip Coat – Is a type of primer applied to grip the surface of the vehicle. It helps any subsequent paint applications to bond.
Grip and Rip - This refers to applying a gripper coat then a full wet coat over the top (see Grip Coat)
Guide Coat: A thin layer of paint that is applied in the opposite colour to the primer coat. Applied when preparing the car for the final paint. It acts as a guide for visual checks for smoothness when sanded.
Hardener: Also known as an ‘activator’, it is a component that is added to the paint allowing it to cure.
High Solids: Is a paint formulated to have higher concentrations of solid components (at least 60%). Applying a high solid paint produces a premium finish and reduces environmental hazards due to low toxicity (low VOC).
Humidity: A measurement of the amount of water vapor in the air. It has an affect on the drying times of paints, especially water based paints.
HVLP: High Volume Low Pressure refers to a spray gun that uses a high volume of air at a low pressure to atomize the paint particles. It is one of the most efficient types of spray guns as less paint is wasted.
Isocyanate: Gives paint it’s hardness and durability. It can be extremely dangerous to health if used incorrectly. Spraying 2-pack isocyanate paints is the main cause of occupational asthma in the UK. Make sure your spray booth is properly equipped with breathing apparatus.
Lacquers: A clear coat that when applied produces a solid durable finish. They are UV resistant and are usually based on nitrocellulose or acrylic resins.
Low Film Build: Often when a film is less than 2 mils when dry it will not protect the base coat and will appear poor in appearance.
LVLP: Low Volume Low Pressure spray guns use less air and a lower air pressure (see HVLP). It applies paint faster making them ideal for large objects and high production applications.
Metallic Paint: Paint that contains a metallic pigment, normally aluminium or mica, creating a metallic finish.
Mica (Pearl): A natural stone mineral with shiny flakes. Creating a sparkly sort of finish.
Mix Ratio: The elements required to blend together a ready to spray paint. For example, a clearcoat with a mix of 4:1 requires mixing of 4 parts of the clearcoat with 1 part activator. Mix volumes are usually calculated by volume.
Molecule: A group of atoms bonded together creating the smallest unit of a substance.
Orange Peel: A finish that appears as an uneven or dimpled surface but usually feels smooth to touch. Normally caused by the wet paint being unable to level out resulting in the paint film surface drying unevenly.
Overall Painting: A refinishing term referring to completely repainting the car.
Overspray: Where paint sprayed overlaps onto areas where it was not meant to be painted creating an uneven blend.
Particle Size: The paint particle size when sprayed.
Pigment: Finely ground particles that are added into paint, providing colour, corrosion resistance and strength.
Polishing Compound: Used to clean and shine the vehicles paint surface.
Pressure Fed Spray Gun: A spray gun that uses a separate paint container which is pressurised and connected to the gun using hoses.
Primer: The most common undercoat when refinishing a vehicle. Used to create a smooth surface for a basecoat to adhere to as well as providing corrosion protection.
Primer-sealer: An undercoat that helps to bond basecoats to the vehicles surface.
Primer-surfacer: A sandable primer used to fill any small imperfections in the vehicles bodywork.
Reduce: When a paint is applied over a primer or basecoat which has not fully cured, the primer will draw in the colour resulting in the drop in gloss. This can also result in solvent pop, this is why flash time is so important.
Reducer: Used to thin paints to a sprayable consistency.
Sagging: Caused by excessive paint flow, causing drips and runs in the paint finish. Can occur not only when the paint is wet but also during the baking process.
Sealer: A specialised primer used to provide and improve adhesion as well as a smooth and level surface for the topcoat to be applied.
Solids: The particles of paint that remain on the vehicles surface after evaporation has occurred forming a film.
Solvent: Usually a liquid, used to dissolve a substance such as resins or binder components.
Spot Repair: A refinishing term referring to a repair where a section of the vehicle has been refinished. This is normally smaller in size than a whole body panel. Also known as dent or ding work, the areas are blended in to match the existing finish.
Spray: Refers to the paint leaving the spray gun. The spray itself is created by atomising the paint by using compressed air and high pressure.
Tack Cloth or Rag: A specialised wiping cloth that is impregnated with a tacky material designed to remove loose particles of dust before painting.
Tack Coat: A light mist that is allowed to dry for a few minutes so that it is still tacky before applying a further coat, helping hold the paint in place and reduce runs.
Thinner: A solvent that is used to thin oil based paints or clean up after their use. (see reducer / solvent)
Topcoat: The final layer of paint applied to a vehicle, this maybe applied over several coats.
Touch Up: A refinishing term referring to correcting issues in the paint work such as minor scratches.
Undercoat: The first coat applied to a vehicle, usually a primer or sealer. Providing corrosion protection and a suitable surface for adhesion for basecoats.
Viscosity: A measurement that refers to the flow rate of a liquid. Usually measured using a viscometer, it measure the amount of time it takes for a liquid to pass through. Viscosity is important to the paint spraying process and maybe controlled by the use of solvents.
Waterborne: Also known as ‘water based’, a type of paint that uses water as it’s main carrier making it environmentally friendly.
Wet on wet – This refers to a coat of primer which is left to flash off and then the base coat (or colour coat) is applied straight away. This technique does not require sanding.