Wet sand the clear coat in a back-and-forth motion. This replaces the orange peel with finer scratches. Start with ultra-fine 1,200-grit sandpaper for DIY painting or 3,000-grit paper if it's a factory paint job. Use light and steady pressure when wet-sanding.
Evenly apply polish to your electric buffer or foam pad and switch on, but a warning: do not put too much compound on the pad or you could burn through the paint. If you're using an electric buffer, turn it on at a low RPM: generally, around 1800 RPM is good.
This might be things like road grime, micro dirt, tiny metal shavings, over spray, hard water deposits and a myriad of other things that find their way into the clear coat of your vehicle's paint.
Nevertheless, many people recommend wet sanding and polishing only after the clear coat as a whole is done, and fully dried out. A lot of water sits between the clear coat and the abrasive sanding material, which helps to sand down the paint, or any tiny imperfections more thoroughly.
Wet sand the clear coat with 400 grit sandpaper, as finer and finer imperfections can replace the orange peel. Finally, fill it with polish. The sanding step helps remove the clear coat until the entire surface is smooth, as sandpaper removes fine scratches from the finish.
Once you've applied a clear coat to your product, don't immediately begin sanding, as this will ruin your hard work. Wait at least 24 hours, but no more than 48 hours. Allow at least 24 hours for the clear coat to dry and harden fully, but if you wait longer than 48 hours, it might become too difficult to sand.
Using an 800 grit sandpaper, sand down the rough clear coat until you can't feel it any more. Go lighter on the surrounding clear coat as you want to smooth and blend the damaged area, not remove more clear coat. Wipe clean with a lint-free cloth and rubbing alcohol to remove any contaminants left by sanding.
If the finish is not glossy, you may not have applied enough coats, or enough clear coat to flow. There is some technique involved here, as too little clear coat will appear dull, and too much will stand up like a bead of glue and take a long time to dry.
When the painting is done under the ideal conditions, the drying time for clear coating will be between 12-48 hours. Generally, the clear coat will dry within this time, making your car fit for driving.
Wait a day or so to let the clear coat harden if the finishing is new. At this point, if you see "orange peel" or "trash" on the surface, wet sand with 1000 or 1200 grit wet or dry automotive grade sandpaper. This will smooth out the surface and allow for a super shine finish.
Be sure to mix in all material that may have settled to the bottom of the can. Never shake a can of clear finish. Shaking will cause bubbles in the dried finish. Always apply thin coats.
The likely cause is that the paint was applied too thin per coat or the nozzle was too far away. A coat thick enough to get a glossy sheen is seen but not too thick that runs develop is the proper technique. Practice on a similar surface is suggested.
As a rule of thumb for my own cars – I usually limit any kind of harsh polishing (Medium Cut or Above ) to two times per year maximum.
Depending on the severity of the orange peel, this should be 1500-grit sandpaper or 2000-grit sandpaper and move up to 3000-grit sandpaper. Sanding blocks of various sizes, including soft blocks. A bucket of water mixed with liquid soap. A sponge or water bottle to keep the surface wet during sanding.
After shampooing, there may still be ingrained, microscopic contaminants on the surface of your paintwork – this is what is causing the 'rough' feel. You can remove them with the G3 Professional Deep Clean Clay Mitt, which has a unique rubber polymer technology and lifts bonded contaminant off the surface very easily.
Wait at least 10 minutes before applying the second coat. This layer can be slightly thicker than the first. Make sure you allow about an hour for this to dry. You can apply three to four layers of clear coat to achieve the glossiest finish.
Keep in mind that compounding or wet sanding does remove clear coat.
Wet sanding is a way to ensure that the clear coat looks as expected, enabling it to provide protection and give your car the polished look you desire. Warning: Don't keep the buffer on one area for more than a couple seconds or you risk damaging the base coat.