Using an air compressor for painting can save money and time while avoiding aerosol propellant contamination. If you want to paint using a pressure spray gun, follow these instructions.
Step
Method 1 of 4: Getting Started
Step 1. Select the required paint and paint thinner
Oil-based enamels are easiest to use with a pressure spray gun, but acrylic and latex paints are fine too. If you add the appropriate thinner, the thicker paint will flow freely through the siphon tube, metering valve and nozzle.
Step 2. Prepare the area where you will paint
Spread a cloth covering, plastic sheet, scrap board or other material on the floor or on top of the furniture. To paint an immovable object, as in the example here, you must protect the surrounding surface and make sure the room has adequate ventilation.
- Protect the surface around the object from being “oversprayed” with tape or newspaper. If you're painting outdoors in windy weather, the paint particles could be carried further by the wind than you think.
- Put the paint and thinner in the right places so that if it splashes, it won't damage anything.
Step 3. Put the paint and thinner in the right place so that if it splashes, it won't damage anything
Step 4. Prepare the surface to be painted
Use scrubbing, brushing, or sanding to remove rust and corrosion from iron, remove grease, dust and dirt and ensure a dry surface. Wash the surface to be painted: for oil-based paints, use mineral spirit; For latex or acrylic paint, use water and soap. Then, rinse thoroughly.
Step 5. Apply a primer on the surface if necessary
You can use a spray gun to apply the primer (following the steps below like using paint) or use a brush or roller. When you're done, you can sand it down to make it smooth if necessary.
Method 2 of 4: Prepare the Compressor
Step 1. Turn on the air compressor
You will use air to apply the primer and test the spray gun. Let the compressor build up pressure while you prepare the paint. The compressor must have a regulator that will allow you to set the correct pressure for the spray gun. Otherwise, the coat of paint will not spread evenly as the pressure will rise and fall as you spray.
Step 2. Set the regulator on the compressor between 12 and 25 PSI (pressure force per square inch)
The exact number will depend on the spray gun used. You can consult the manual (or look directly at the compressor) for more details.
Step 3. Attach the clutch hose to the spray gun
Make sure you attach it tightly. Wrap the thread with Teflon tape to ensure that no air can escape. This step is not necessary if the spray gun and hose are equipped with a quick-connect coupling.
Step 4. Pour a small amount of thinner into the paint tank
(This is the tank attached to the bottom of the spray gun). Use just enough diluent to soak the siphon tube in it.
Step 5. Open the metering valve slightly
This valve is usually one of the bottom screws of the two that sit above the spray gun grip.
Step 6. Do the first bait
Point the nozzle at the empty bucket and press the lever/trigger. It usually takes a few seconds before the liquid passes through the entire system. Initially, only air will come out of the nozzle, but after a while, you will see a stream of paint thinner. If the paint thinner doesn't come out, you may have to disassemble the spray gun to find any clogs or loose parts in the siphon tube during installation.
Step 7. Empty the paint tank if there is any remaining thinner
You can use a funnel to help pour the remaining thinner into the original can. Mineral spirit and turpentine (two widely used paint thinners) are flammable solutions and should only be stored in their original containers.
Method 3 of 4: Painting
Step 1. Mix enough paint
After opening the paint can, mix thoroughly, then pour as much as you need into a separate clean container. If the paint has been in storage for some time, we recommend that you sift it to remove any lumps of paint that may have formed. These clumps can clog the siphon tube or metering valve and impede paint flow.
Step 2. Dilute the paint with the appropriate thinner
The exact ratio of paint to thinner will depend on the type of paint, spray gun, and nozzle type, but generally paint should be diluted around 15-20% for good shine. Look at how thin the paint is when you use the aerosol spray. You can get an idea of how thin the paint should be.
Step 3. Pour the paint into the paint tank until full and fix it securely on the spray gun
The paint tank may be attached to the bottom of the spray gun with a clamping device and hooks or screws, make sure you attach it securely. Do not let the paint tank fall suddenly while you are painting.
Step 4. Hold the spray gun about 12-25 cm from the surface of the object
Practice moving the spray gun in a left and right motion, or up and down, parallel to the surface. If you've never used a spray gun like this before, practice holding and swinging it for a while to get used to it.
Step 5. Press the trigger to spray paint
Move the spray gun each time you press the trigger to prevent the paint from dripping and dripping from spraying too much in an area.
It is best to test the operation of the spray gun on a piece of wood or cardboard before applying it to an actual object. This way, you can adjust the nozzle to get a thinner beam if necessary
Step 6. Try to have each spray slightly overlap
In this way, the result of the painting looks even, there are no parts with a very thin layer of paint. Take care not to drip or run off the paint by moving the spray gun fast enough so that the spray isn't too thick in places.
Step 7. Refill the paint tank as needed until the entire surface of the object has been painted
Do not leave paint in the tank. If you must pause, remove the tank and squirt the thinner through the sprayer before you leave it unused.
Step 8. Let the paint dry
You can apply a second coat of paint if necessary. For most paints, an even coat (even if it's still "wet") will suffice, but a second coat will give a lasting result. Sanding each coat of paint is recommended if you will be using varnish, polyurethane paint, and other lacquer paints to allow each coat to blend well.
Method 4 of 4: Cleaning the Spray Gun
Step 1. Empty the paint tank
If there is still a lot of paint left, you can pour it back into the original container. However, keep in mind that this remaining paint has already been diluted. So, if you want to use paint for your next project, add an appropriate amount of thinner.
Epoxy paints and paints containing catalysts should not be put back in their original containers. You'll need to drain it entirely or dispose of it properly after mixing
Step 2. Rinse the siphon tube and paint tank with thinner
Wipe off excess paint with a rag.
Step 3. Fill the paint tank with about of the thinner, shake it, and spray it through the spray gun until the liquid emitted is clear (clear)
If there is a lot of paint remaining in the tank or in the device system, you will have to repeat this step several times.
Step 4. Remove all the tape and paper you used in the work area
You should do this as soon as the paint dries. The tape that is left on for too long will be difficult to remove because the glue has hardened.
Tips
- Get used to always Clean the spray gun thoroughly after use. If the oil-based paint dries, you may need to use acetone or a varnish thinner.
- Paint horizontally or vertically, but not both for the same object as it will leave a slight texture that looks different when viewed from different angles.
- Read the instructions or user manual to operate the spray gun. You must understand the capacity, viscosity, and type of paint to be used. The regulator contained in the spray as shown in the picture above is fairly common for this type of spray gun. The regulating valve at the top controls the air volume; a valve underneath regulates the flow of paint. The front of the nozzle is held in place by a threaded ring, and the paint jet can be changed from vertical to horizontal by turning this ring.
- If possible, mix enough paint to complete one project. The next mixture may have a slightly different color.
- Painting with a pressure spray gun instead of an aerosol allows you to choose your own color, reduces air pollution and saves money. However, the use of a spray gun releases large amounts of volatile organic compounds (VOCs), which are used as solvents in most paint manufactures.
- Use a catalytic damper to paint the car. This product is specially designed to speed up drying time and prevent paint from melting, without affecting the finish or color of the paint.
- There is nothing wrong with using an air filter or dryer to remove moisture and dirt from the compressed air duct. You will have to pay extra for this.
- Use hot water (approximately 50 °C) to thin water-based paints. Acrylic paint can only be diluted 5% with hot water.
Warning
- Never disconnect the air hose while the compressor is charging.
- Wear a respirator if you are painting for an extended period of time. You can buy it for around IDR 50,000-IDR 100,000 to prevent lung infections. The respirator will filter the paint fumes and you won't even smell the paint even if you're working indoors.
- Paint only in a well-ventilated room.
- Some paint products use highly flammable solvents, especially “dry fall” or varnish-based paints. Avoid sparks and open flames and do not allow toxic fumes to accumulate in confined spaces.
