how to re-paint your frame

13 steps to re-spraying your bicycle frame 

1
Completely remove any items you don't want painted, such as the bottom bracket or forks. Areas of the frame with threads for bolts can either be covered with painter's tape, or the bolts can be put in, (you don't want paint preventing you from putting it back together). •Be careful when taking the bike apart. The headset area (where the handle bars and forks attach to the frame) are quite complicated. You should definitely take notes and pictures of how the parts were aligned when you take them out, so that you can get them back in correctly. The cups that are pressed into the frame should be removed to properly paint the bike. Removal without deforming them is difficult without the proper tools. Consider taking your frame to a bicycle shop for this final step of the break down. They should be able to remove them on the spot for free, or very cheap.
•Also, buy some bicycle-specific grease and use your hand to apply to the bearings and internal mechanisms; this will ensure smooth operation and protect these parts from wear.

2
Degrease the bike. You can use bike degreaser or car body wipe   

3
Remove all of the existing paint with medium-grade sandpaper or rough sponge (80 grit) to form a smooth surface. See Tips for other options. •If you are lucky enough to have a carbon frame, make sure that you do not sand the carbon. You may have to leave some of the paint in place.
•If there are any dents or wear marks which you want to fill in, this is the time to do it. You can use knifing putty, or something similar to produce a smooth surface. Make sure that you sand it down well afterwards, and remove the dust.
    

4 Hang the bike by the head tube to ensure that your paint does not clog up at the bottom bracket. A coat hanger works great. Hang it in an area that you have good access to (a clothes line is perfect,) as you will need to be able to move around the whole bike and underneath it, too. Also, make sure you hang your bike in a well ventilated area, with good light to help check that you have applied an even coat

5 Apply a primer with very thin coats to provide the best finish. Follow the instructions on the can (typically spray about 20cm from the surface). Start at the joints and bottom bracket in the frame. These are the hardest bits to paint, and the easiest places to get runs or miss a spot. Wait about 15 minutes between coats, and don't worry about it if you don't fully cover the frame in the first or second coat, because you will be applying several coats. •Make sure you buy the right type of primer, as the colour of the primer depends on what your final colour will be. Also, look for a primer that resists rust or a rust converter, (rust inhibitor).
•If you are refurbishing an aluminium frame, you may need to get a special primer or an thalidomide coating, which ensures that the pores in the aluminium do not affect the finish.
•When priming the bike, especially if you are outside, wear goggles and a mouth mask. It is not a nice feeling to have paint fly into your eyes whenever a gust of wind comes. Also wear gloves, because some paints strip your skin.

6
Allow the frame to dry for about 24 hours. Try to let it dry in the place you painted it. If this is not possible, lay it carefully on newspapers, and try not to touch it, since the paint is easily damaged.

7
Sand the primer using 220-grit paper/sponge. Your aim is to achieve a smooth surface which the next layer of paint can adhere to

8
Put on your main coat of paint. Once again, make sure your bike is clean of dust and any grease. To apply the color, follow the same steps as you did for the primer, ensuring you apply thin coats until you have a uniform finish. If you wish to paint the frame in multiple colours, you simply apply the lighter paint first, applying till an even coat is achieved (3 or 4 coats), then mask over the area you wish to remain the light colour, and paint the darker colour on.

9
Sand it down again after the paint dries, this time using some wet-or-dry 1200-grit paper. When sanding with the 1200-grit sandpaper, make sure to "wet-sand" the finish. This keeps the sandpaper from "loading". Wet-sand by taking some Windex, and spraying the Windex onto the paint, and then sand. Make sure you keep the finish "wet" while you're sanding. All you are trying to do is to take the gloss off the paint producing a matte finish for the lacquer to stick to. The lacquer will make the paint shiny again.

10
Put stickers or decals on your bike (optional). The lacquer you put on afterward will protect the stickers; however, unless you have very thin stickers, it is unlikely you will get a completely smooth surface. If you want to buy decals, have a look online, as there are many replica decals for major bike manufacturers

11
Apply the clear lacquer in the same way as you painted the bike; however, this time you may only need to put on 2 or 3 coats. It is important, especially at this stage, that you do not have the spray can too far from the surface as you could end up with a rough surface.

12
Complete the repainting of your bike by following the steps for the frame with the forks or any other part. Allow the lacquer to harden for at least a week before putting the bike together, or you may damage your beautiful new paint job

13
Finished

and now enjoy your fresh new paint job and be careful when putting you new parts on as not to damage or scratch your new paint