Finish sanding, also known as color sanding, is the process of wetsanding after the final coat of clearcoat is applied to your paint project. This process does not involve actually sanding the paint color; it only involves wetsanding the clearcoat. Color sanding is an old term that no longer accurately reflects the actual process, yet the name has stuck.
With waterborne paint, sanding the actual basecoat of color is neither required nor recommended, and wetsanding is not possible. If you have an imperfection or dirt in the basecoat, you can de-nib it with 1000 grit dry sandpaper, and then you must reapply another coat of the basecoat. In this case, focus only on the area that needs to be de-nibbed or the imperfection removed. Do not sand the entire area.
When describing finish sanding, we are referring to the process of using a very fine grit of sandpaper (3000+) to wetsand an area that has orange peel texture, has some minor dirt, or needs the gloss factor enhanced. There are videos and resources that will indicate that you can use 1500-2000 grit sandpaper to do this work. We strongly recommend that you do not. These resources typically apply to experienced professionals.
We recommend the finer grits of sandpaper to reduce the risk of permanently damaging your paint project. We even use up to 8000 grit at times. This finer grit allows a safe, controlled wetsanding process. However, the process will take longer due to the less aggressive nature of the sandpaper.
Additionally, we do not generally recommend finish sanding jobs completed with the touch up brush, pen, or combo. The issue with those applicators is that they do not leave a perfectly even, uniform coat on the substrate. Therefore, when sanding, it is very easy to sand through the paint you’ve applied, exposing the primer or substrate underneath. You are then forced to redo the entire repair. However, it can be done. If attempting to finish sand a repair made by the brush, pen, or combo, the steps are the same as the aerosol sprays or professional sizes.
These are the steps for finish sanding
What you need for finish sanding
- A cup of water to dip the sandpaper in and/or a spray bottle filled with water
- A sanding block (optional)
- 3000 grit sandpaper
- 5000 - 8000 grit sandpaper
- Polishing compound
- 2x Soft cloths (one for polishing and one for wiping off the sanding water and residue)
- Ensure the clearcoat has dried for at least 48 hours. Dip the 3000 grit sandpaper into the cup or water or use the spray bottle of water to wet the area to be sanded. If using a sanding block, wrap the 3000 grit sandpaper around the block.
- Lightly and evenly begin sanding the area in a circular motion. Do not press too hard, and do not concentrate in one small area. Keep an even, light pressure the entire time while sanding. Keep the area being sanded very wet by dipping the sandpaper in the water or using the spray bottle.
- After a short time, use one of the soft cloths to wipe off the sanded area and inspect. The sanded area should look uniformly dull. Any spots that still look shiny are areas the sandpaper did not reach. You can recognize these areas because they appear the same color as the paint did prior to beginning wetsanding. If these spots are minimal you do not need to continue with the 3000 grit sanding. CAUTION! Do not over-sand. If you sand too much and penetrate the clearcoat down to the basecoat, you must repaint the area.
- Once satisfied that the area is uniformly sanded with 3000, you will now switch to 5000 - 8000 grit sandpaper. The wetsanding process is exactly the same as above. The only difference you will notice will be the gloss will begin to return to the paint that is being sanded.
- Continue this process until you see a uniform finish again. The paint will not be as glossy as the unsanded areas, but you should be able to see your reflection.
- Once satisfied that the area is again evenly and uniformly sanded, it is time to move to the polishing compound. We recommend the TouchUpDirect Polishing Compound. If you are using a different brand, follow the instructions on the compound.
- To use the TUD Polishing Compound, apply a dime-sized amount to a clean, soft cloth.
- Begin polishing in a circular motion the area that was wetsanded. This process can take some time to fully restore the total depth of gloss. Using an orbital polisher or a hand drill polishing pad can speed up the process of restoring the gloss.
Note: Once complete, if you need to re-sand a particular area, the entire process needs to be performed again but only in the area that needs additional sanding.