Paint Spraying: Spray gun parts Student A: You need to replace some parts for your spray gun. However, you don t know the name of the part, or the part number. Telephone a paint gun supplier and order the parts you need. The supplier will give the name of the part and the part number. Write this down in the box below: Item n Quantity Part number Description
Student B: A customer telephones you and needs to order some parts for a spray gun. Your customer only has the diagram of the parts and doesn t know the part numbers or the name of the parts. Give the customer this information and take his/her order. Taken from: Wagner operating manual.
Paint Gun Problems List the cause of the problems and solutions below Problem Cause Solution Little or no material flow (10) Material leaking (4) Spray pattern to thick, runs and sags (7) Spray jet pulsates (3) Too much overspray (2) Pattern is very light and splotchy (3) Orange peel/ rough finish (2) Check your responses with a partner then check with the chart on next page.
Paint Spraying : Read the text below Painting your car is a time-consuming job. You'll need plenty of sandpaper, an electric or air-powered sander, masking tape, newspapers for masking off, an air compressor and a spray gun, a buffer, paint thinners, face masks, safety glasses, undercoat, topcoat acrylic or enamel paint, and clear-coat lacquer. A dust extractor, while not essential, will help keep the area clean. For a small- or medium-size car, you'll need approximately one gallon of primer, three gallons of topcoat, and two to three gallons of clear coat. Preparation Clean your working area to remove dust. If you're spraying outside, hose the area down. Then wash the car down and clean the surface of any dirt, grease, or road grime. Decide whether you want to paint details such as the engine bay, inner doorsills, and trunk. This will dramatically add time to the job because you'll need to strip the car down to its bare shell, including removing the engine. However, if it's just the exterior you're looking to improve, then simply mask the areas you don't want painted. Put on your dust mask and protective eyewear, and turn on the dust extractor. Stripping Start sanding using circular motions. You may have to sand corners and crevices by hand. The best finish is achieved by sanding the entire car back to bare metal with a perfectly smooth finish. This can be time-consuming. If time is limited, you don't have to go to bare metal. Just make sure you get a smooth, even surface by finishing the last part with a fine-grade wet-and-dry sandpaper. Wipe the whole surface down with a clean rag and thinners to remove dust, and wait until residue from the thinners evaporates completely before continuing.
Priming Mask up areas you don't want to paint using masking tape and newspaper or plastic sheeting. Mix the primer with thinners using the ratios recommended on the paint can instructions. It will vary for different paints. Before you start painting for the first time, it's best to practice your spraying technique. Hold the spray gun approximately 6 inches from the panel and spray in a side-to-side sweeping motion. Apply the trigger only when you are moving the spray gun. If you hold it continuously as you spray, the paint will be thicker in the spots where you change direction, causing runs. When you've got your technique correct, start applying the primer on the car, working from the roof down. Apply the primer in thin, even coats. It will usually take two or three coats to cover the surface completely. Each coat will take about 10 minutes to apply per panel and between 20 minutes to an hour between recoating for the primer to cure. The primed surface will have a powdery finish, so use 2000-grit wet-and-dry sandpaper to lightly sand the surface to a smooth, even finish. Clean the spray gun and wipe down the primed surface with a rag slightly dampened with thinners. Painting As with the primer, mix the paint with thinners using the recommended ratios on the paint can instructions. Apply the topcoat paint using the same spraying techniques. Each coat will take about 10 minutes to apply per panel and between 20 minutes to an hour between recoating for the paint to cure. Apply three to four coats using the recommended drying time between coats. Before applying the last coat, remove any powdery residue with 2000-grit wet-and-dry sandpaper and wipe down with a clean rag. Repeat the last two steps with the clear-coat lacquer. Remove the masking while the clear coat is still wet, being careful not to get any tape or paper stuck on the wet paint. Let the clear coat cure for the recommended time. Inspect the finished job for runs or imperfections. If you find any, sand back affected area with 2000-grit wet-and-dry sandpaper and respray. Buff paint in circular motions with a buffer, being careful not to burn the paint by holding the buffer in one spot too long. Prepare to explain the process next lesson - WITHOUT READING