How to Paint a Bike
To paint a bike, start by disassembling it until you're left with just the frame. Then, sand the frame with a low-grit sandpaper, which will help the paint stick. When you're finished, apply painter's tape to any areas of the frame that you don't want to paint. Next, apply several coats of high-quality spray paint to the bike, letting it dry in between coats. Finally, apply a clear coat and let the bike dry for 24 hours before reassembling it.
Disassemble your bike until you’re left with just the frame. Remove both wheels, the left and right cranks, the bottom bracket, the front and rear derailleurs, the chain, the brakes, the handlebars, the seat, and the front forks. If you have any attachments on your bike, like a water bottle holder, take the screws off from those too. Put the screws and tiny parts from the bike in labeled plastic baggies so it's easier to reassemble it later. Remove any labels or decals from the bike frame. You might have a hard time taking them off if they're old and really stuck on there. If they won't peel off, use a blow dryer or heat gun to warm them up. The adhesive on the labels will loosen when it's warmed, making it easier to remove the labels from the frame. If you're having trouble peeling a label off with your fingers, use a putty knife to lift the edges of the label up off the frame. Wipe down the frame of the bike before you sand it. If there's any glue residue left over from the decals, spray a product like WD-40 on the frame and wipe off the residue with a cloth. Sand the frame of the bike so the new coat of paint is able to stick. If the frame has a thick or glossy paint on it, use a low-grit (rough) sandpaper to remove a lot of the old paint. If the frame has a matte paint on it or it's completely bare, use a high-grit (fine) sandpaper. Wipe the bike down thoroughly and let it dry. Use a cloth with soapy water. Apply painter’s tape to the areas of the frame you don’t want to be painted. There are a few parts of the frame that should be left paint-free: The posts for the brakes. Any bearing surfaces. Any threads on the bike where something will need to be screwed in when you reassemble it. Put together a painting station outside. If you can't work outside, make sure you set up in a well-ventilated area, like a garage with the garage door open. Lay a tarp or newspaper on the ground to catch any paint that drips. You'll also want to have a pair of safety goggles and a dust mask on hand. Hang the bike frame by looping wire or rope through the head tube. If you're painting outside, look for something to hang the wire or rope from, like a tree branch or a rafter on a covered porch. If you're working inside, hang the wire or rope from the ceiling. The goal is to hang the frame in a location where you can easily walk around it and paint every side. Mount the frame on a table if you can’t hang it. Put a broomstick or dowel through the head tube and clamp it onto a table so that the frame is securely elevated in the air off to one of the sides of the table. If you don't have a table, you can mount the frame on a desk, stand, or other structure that will hold the bike off the ground. Use a high-quality spray paint to paint the frame. Look online or in your local hardware store for spray paint that is specifically made for use on metal. Avoid generic brands that will leave the coat on the frame looking uneven. Never combine different brands of spray paint. The different paints might react badly with each other. If you want the bike frame to look matte instead of glossy, look for spray paint that says “matte finish” on the can. Spray paint the first coat on the bike frame. Hold the can of spray paint around 1 foot (0.3 m) (30.48 cm) away from the frame while you're spraying it, and keep the can in constant motion. Avoid spraying continuously in one area, or you will end up with drip marks. Make your way around the entire frame until the whole surface has been covered with paint. Don't worry if you still see some of the old paint showing through the first coat. You want to do several thin coats as opposed to one thick coat, so the old paint will be covered up after you apply more coats later on. Let the first coat dry for 15-30 minutes before you apply the second coat. Once the first coat is completely dry, repeat the spray-painting process, making sure you get another thin, even coat on the frame. Continue applying coats of paint until the old frame is completely covered. Always wait 15-30 minutes in between coats. The amount of coats you need will depend on the color and type of spray paint you use. When you can't see the old paint or metal on the frame, and the new paint looks even, you've applied enough coats of paint. Apply a clear coat to protect the bike from rust and keep it looking new. Wait a few hours after spray painting before you apply the clear coat. Once the frame is completely dry, spray an even layer of clear coat all over the bike, similarly to how you applied the spray paint. For the best results, apply three coats of clear coat. Let each coat dry for 15-30 minutes before you apply the next one. Let the bike frame dry for a full 24 hours. Avoid touching or moving the bike during this period. If you painted outside, check the weather forecast and carefully move the bike inside if it's going to rain or snow. Once it's completely dry, go ahead and remove any painter's tape you put on it during the prepping stages. Reassemble the bike. Put back on all of the parts you detached from the frame earlier, including the wheels, the bottom bracket, the chain, the left and right cranks, the front and rear derailleurs, the handlebars, the brakes, the seat, and the front forks. Now you're ready to try out your brand-new looking bike! 
Disassemble your bike until you’re left with just the frame. Remove any labels or decals from the bike frame. Wipe down the frame of the bike before you sand it. Sand the frame of the bike so the new coat of paint is able to stick. Wipe the bike down thoroughly and let it dry. Apply painter’s tape to the areas of the frame you don’t want to be painted. Put together a painting station outside. Hang the bike frame by looping wire or rope through the head tube. Mount the frame on a table if you can’t hang it. Use a high-quality spray paint to paint the frame. Spray paint the first coat on the bike frame. Let the first coat dry for 15-30 minutes before you apply the second coat. Continue applying coats of paint until the old frame is completely covered. Apply a clear coat to protect the bike from rust and keep it looking new. Let the bike frame dry for a full 24 hours. Reassemble the bike. 