A paint repair can look excellent or ordinary before any colour is sprayed. The difference is usually sanding. This automotive sanding grit guide gives you a practical way to select the right abrasive for chips, scratches, filler work, primer preparation and clear coat finishing. Start too coarse and you create scratches that show through. Start too fine and the surface may not level properly or give the next coating enough grip.
How automotive sanding grit numbers work
A sanding grit number refers to the size of the abrasive particles on the paper. Lower numbers cut faster and leave deeper scratches. Higher numbers cut more slowly and leave a finer scratch pattern.
There is no single best grit for automotive work. The correct choice depends on what is on the panel, what you are trying to remove, and what product goes on next. Sanding bare steel is different from levelling body filler. Preparing primer for base coat is different again from flatting clear coat before polishing.
For most DIY repairs, work through the grits rather than trying to achieve the final finish with one sheet. Each finer grit removes the scratch pattern left by the previous one. Skipping too far can leave deep marks behind, especially under metallic and pearl colours where defects are more noticeable.
Automotive sanding grit guide by repair stage
40 to 80 grit: stripping and heavy shaping
Use 40, 60 or 80 grit when you need serious cutting power. This range suits stripping failed paint from a small area, removing rust after the affected metal has been properly dealt with, and rough-shaping body filler during a dent repair.
These papers remove material quickly, which is useful but unforgiving. Avoid using them on sound paint outside the repair area or on thin panel edges. Deep 40 or 60 grit scratches require several later sanding stages to remove, so use the coarsest paper only where the job genuinely calls for it.
For a small stone-chip repair, this range is generally far too aggressive. You are better off cleaning the chip, feathering only loose material and using an appropriate primer where bare metal is exposed.
120 to 180 grit: refining filler and feathering paint edges
Once filler has been shaped, move to 120 grit and then 180 grit to refine it. This is also a useful range for feathering the edge between an existing paint finish and the repair area before primer.
A feather edge should feel smooth when you run a clean fingertip across it. You should not be able to feel a hard paint ridge. If the edge is left sharp, it can print through primer and become visible after painting.
Use a sanding block on flat or gently curved panels. Sanding with just your fingertips concentrates pressure and can leave grooves and low spots. A block keeps the repair flatter and makes it easier to see whether the filler is level with the surrounding panel.
240 to 320 grit: final filler preparation and primer sanding
The 240 to 320 grit range is a common transition point in refinishing. Use it to remove the 180 grit scratch pattern, smooth repaired filler before priming, or sand primer surfacer once it has cured.
If you are applying a high-build primer over a repair, 240 grit is often suitable for final preparation of the filler and feathered paint edge. The primer is designed to fill minor sanding marks and small imperfections. For a finer primer finish before colour, use 320 grit, particularly where a solid colour will be applied.
Do not assume primer will hide every mark. Heavy scratches, pinholes in filler and poorly feathered paint edges can remain visible after several coats. Apply primer, allow it to cure as directed, then use a guide coat if needed. Lightly sanding the guide coat reveals high and low spots before colour goes anywhere near the panel.
400 to 600 grit: preparing primer for base coat
For most base coat systems, 400 to 600 grit is the practical range for final primer preparation. A 400 grit dry finish is often suitable for small repair areas, while 600 grit wet or dry provides a finer surface for base coat application.
Metallic, pearl and light colours benefit from a consistent, fine sanding pattern. Coarse scratches can telegraph through these finishes, particularly in direct sunlight. If you are spraying a factory-matched aerosol base coat or a base coat from a larger kit, prepare the primer evenly rather than sanding only the centre of the repair.
When using wet-and-dry paper, keep the paper clean and use fresh water. A small amount of suitable lubricant can help prevent loading, but avoid contaminating the surface. After sanding, wash away residue, dry the panel completely and wipe it with a suitable wax and grease remover before masking and painting.
800 to 1000 grit: blending and finer paint preparation
Use 800 to 1000 grit where a finer key is required, such as preparing an existing clear-coated area for blending, smoothing a minor imperfection in cured primer, or preparing certain finishes before repainting. This range is less aggressive, so it is better for preserving surrounding paint where possible.
It still needs a purpose. Sanding bare metal or fresh filler with 1000 grit wastes time and may not provide the adhesion profile required for the next coating. Follow the product instructions for the primer, base coat or clear coat you are using, as systems can have different recommendations.
For a small scratch that has not broken through the clear coat, 1000 grit may be part of the correction process. However, if the scratch catches a fingernail or exposes colour or metal, it is likely a paint repair rather than a simple polish job.
1200 to 2000 grit: correcting clear coat defects
Once clear coat has fully cured, 1200 to 2000 grit is used to remove dust nibs, minor runs, orange peel and other surface defects before machine polishing or hand polishing. Begin as fine as the defect allows. For a small dust nib, 1500 or 2000 grit is normally safer than 1200 grit.
Keep the paper wet, use light pressure and inspect constantly. The aim is to level the clear coat, not sand through it. Panel edges, swage lines and raised body contours have less paint thickness and are the first places people burn through. Mask them or stay well clear when sanding and polishing.
A run may need 1200 or 1500 grit to level it, followed by 2000 grit to refine the sanding marks. The panel then requires a cutting compound and finishing polish to restore gloss. If you can still see a run but are unsure how much clear coat is available, leave it rather than risking a repaint.
2500 to 3000 grit: polishing preparation
Ultra-fine 2500 and 3000 grit discs or paper make compounding easier after clear coat correction. They reduce the time and heat needed to remove sanding marks, which is useful on larger panels and fresh resprays.
These grits are for refining, not for removing major defects. They will not efficiently flatten a heavy run or deep dirt inclusion. Work progressively: level the defect with the least aggressive grit that works, then refine the marks before polishing.
Dry sanding versus wet sanding
Dry sanding is cleaner for shaping filler and sanding primer with a dust extraction system. It is also easier to see the panel surface as you work. Quality dry abrasive discs paired with an orbital sander are efficient for broad primer repairs, but an orbital can cut quickly on edges and contours.
Wet sanding is commonly used for fine finishing, clear coat correction and hand-sanding smaller areas. Water helps carry away abrasive residue and keeps the paper from clogging. The trade-off is mess, and trapped water can cause problems if the panel is painted before it is completely dry.
Use waterproof wet-and-dry paper for wet sanding. Ordinary dry paper breaks down quickly in water. Whether sanding wet or dry, replace loaded paper rather than pressing harder. Dull abrasive creates heat, uneven scratches and poor results.
A sensible grit sequence for common jobs
For a filler repair, a typical sequence is 80 grit for initial shaping, 120 to 180 grit for refinement, 240 grit before primer, then 400 to 600 grit on cured primer before base coat. The exact starting point depends on how much filler needs shaping.
For a chip that has exposed metal, lightly feather loose paint with 320 to 400 grit, apply the correct primer, sand the primer with 600 grit once cured, then apply colour-matched base coat and clear coat as required. A touch-up pen or brush bottle is often the better option for tiny chips where a sprayed repair would be excessive.
For clear coat correction, start at 1500 or 2000 grit for a minor defect, refine with 2500 to 3000 grit, then compound and polish. Do not sand through clear coat simply to chase a perfect flat finish on an older vehicle.
Avoid these sanding mistakes
The most common mistake is using coarse paper to speed up a job, then failing to remove its scratches with finer grits. The second is sanding too large an area. Keep the repair controlled, but allow enough room to feather edges and blend colour where the repair method requires it.
Cleanliness matters as much as grit choice. Blow or wipe sanding dust away between stages, use clean cloths and keep silicone, polish residue and greasy fingerprints off the panel. Contamination can cause fish-eyes, poor adhesion and uneven paint flow.
Also check what you are sanding. Factory finishes, old repairs and unknown aftermarket coatings can react differently. If the existing coating is cracking, lifting or unstable, sanding and painting over it may only hide the problem temporarily. Remove failed material and rebuild the area with the correct filler, primer, base coat and clear coat system.
Choose the grit for the job in front of you, not the grit you happened to find in the shed. A controlled sanding sequence gives factory-matched colour and clear coat the smooth, sound surface they need to look right when the vehicle rolls back into the sun.