When I first started painting cars, I had no idea how important the small details were. I was more focused on the color, the spray technique, and how shiny the final coat looked. But as I kept practicing and learning, I realized one of the most important things you can do is sand between coats.
It’s not just about looking good—it’s about making sure the paint job lasts, holds up to weather, and actually feels smooth to the touch.
Photo by reddit
If you’re getting ready to paint your own car or thinking about taking it up as a DIY project, you might be wondering if sanding between coats is really necessary.
Let me tell you from experience—it absolutely makes a difference. Let’s go over why it’s important, when you should sand, what tools you need, and how to do it properly.
Why Sand Between Coats of Paint?
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Sanding between coats helps your next layer of paint stick better. Every time you spray a coat, there can be little imperfections—like dust particles, orange peel texture, or tiny bubbles. Sanding knocks those down and gives the next layer something to grip onto.
Think of it like painting a wall. You wouldn’t paint over rough drywall without sanding first, right? The same idea applies here. You want a smooth surface that allows each new coat to bond better.
Without sanding, your paint might peel later, or you might end up with a bumpy finish that doesn’t look very professional.
What Happens If You Don’t Sand Between Coats?
If you skip sanding, especially on your base or clear coats, here’s what might happen:
- The paint won’t adhere properly
- You could trap dust or dirt under the next layer
- The finish may feel rough or uneven
- You might see fish eyes or bubbling later
- It’ll be harder to get that deep, mirror-like shine in the end
I made the mistake once of not sanding between clear coats on a hood I repainted. Looked great for a week—then it started peeling around the edges. I had to redo the whole thing. Never again.
When Should You Sand Between Coats?
This part is really important. You don’t want to sand every single time without knowing which coat you’re on. Here’s a basic breakdown of when to sand:
| Coat Type | Sand Between Coats? | Why It Matters |
|---|---|---|
| Primer | Yes, lightly | Smooths out surface, removes imperfections |
| Base Coat | Sometimes, if needed | Only sand if you see runs, dust, or roughness |
| Clear Coat | Yes, especially before final coat or buffing | Ensures a smooth, glossy finish |
I usually sand between coats of primer every time. With base coats, I don’t sand unless I see something wrong. With clear coat, though? Always. That’s where the magic happens if you want a slick finish.
How Long Should You Wait Before Sanding?
Time matters here. You can’t just spray and then start sanding 10 minutes later.
For primer, wait until it’s dry to the touch—usually 30 to 60 minutes depending on the brand and temperature. For base coat, follow the product’s instructions, but usually wait at least an hour.
And for clear coat, I give it at least 24 hours before sanding if I’m prepping for polishing or applying another clear coat.
Here’s a quick reference:
| Coat Type | Dry Time Before Sanding |
|---|---|
| Primer | 30 minutes to 1 hour |
| Base Coat | 1 to 2 hours |
| Clear Coat | 24 hours |
Always read the label of the product you’re using. Different brands have different formulas, and the dry time can vary depending on the humidity and temperature in your workspace.
What Grit Sandpaper Should You Use?
Using the right grit sandpaper is another important step. Too coarse, and you’ll scratch the surface. Too fine, and you might not remove imperfections effectively.
Here’s what I recommend based on my own experience:
- For primer: Use 400 to 600 grit wet/dry sandpaper
- For base coat: Use 800 to 1000 grit if sanding is necessary
- For clear coat: Use 1500 to 2000 grit for in-between coats or polishing prep
Always sand wet if possible, especially with finer grits. It reduces scratches, helps prevent clogging, and gives a smoother result. Keep a spray bottle of water nearby and wet your surface and sandpaper often.
Dry Sanding vs Wet Sanding
This is a question I hear a lot. “Do I dry sand or wet sand between coats?”
Here’s how I usually break it down:
- Dry sanding: Faster, good for rough shaping or sanding primer quickly. Creates more dust.
- Wet sanding: Slower, cleaner, and gives a smoother finish. Best for base and clear coats.
Personally, I always switch to wet sanding once I get past the primer stage. It’s just cleaner, more forgiving, and the results speak for themselves.
How to Sand Between Coats Properly
Let’s go through the process step by step. I’ll keep it simple.
- Wait for the coat to fully dry. Don’t rush it.
- Inspect the surface. Look for any dust, runs, or texture.
- Choose the right sandpaper grit.
- Use a sanding block or foam pad for even pressure.
- Sand using light, even strokes. Don’t press too hard.
- Keep the area wet if you’re wet sanding. Use clean water.
- Wipe the surface down with a tack cloth when done.
- Let it fully dry again before applying the next coat.
If you follow this routine, your paint job will come out smoother, cleaner, and more professional-looking.
Dealing With Runs or Dust in the Paint
Let’s say you get a run or a speck of dirt in your paint. Happens to the best of us. Don’t panic.
Wait for it to dry, then sand that specific area using a small piece of 1000 or 1500 grit sandpaper. Feather out the edges, don’t dig in. Then reapply the coat lightly in that area. You can blend it in pretty well, and once you add clear coat, it’ll look much better.
How Many Coats Should You Apply?
I usually go with this rule:
- Primer: 2 to 3 coats
- Base Coat: 2 to 3 coats
- Clear Coat: 3 coats
Too few coats, and you won’t get the depth or durability you need. Too many, and you risk runs or peeling. Sanding between them helps you get it just right.
How to Know If You’ve Sanded Enough
The surface should feel smooth, almost like satin. You shouldn’t see shiny spots—that means the paint is still too glossy and needs more sanding.
A dull, uniform surface is what you’re aiming for. That means your next coat will have something to bite into.
Tips for Best Results
Let me leave you with some helpful tips I’ve picked up over the years:
- Always clean your surface before painting or sanding
- Don’t rush—good paint takes time
- Use proper lighting to spot flaws
- Wear a dust mask and gloves for safety
- Practice on scrap panels if you’re unsure
Getting a great finish takes patience, but it’s totally worth it when you step back and see your car shining like it just came out of the shop.
Conclusion
So, should you sand between coats of paint on a car? Absolutely—if you want your work to last, look good, and feel professional. It’s not just about aesthetics, it’s about proper adhesion and surface prep.
I’ve painted panels without sanding between coats before, and every time I do, I regret it. A few extra minutes of sanding can save you hours of rework down the line.
If you’re repainting a bumper, restoring a classic car, or just touching up a scratch, sanding between coats can make the difference between an okay job and a fantastic one. Take your time, follow the steps, and your car will thank you for it.
FAQs
Should I sand base coat before clear coat?
Yes, but only if the base coat has imperfections like dust or runs. If it’s clean and smooth, you can apply clear coat without sanding. Just don’t wait too long, or it might lose its tack.
Can I wet sand primer before painting?
Yes, in fact, wet sanding primer is a great way to smooth it out. Use 400 to 600 grit wet/dry sandpaper for best results.
What grit sandpaper should I use before clear coat?
1500 to 2000 grit is ideal. It smooths the surface without scratching too deep, helping the clear coat stick well and shine better.
How do I remove runs in the paint?
Wait for the paint to dry, then carefully wet sand the run with 1000 to 1500 grit paper. Blend the area out, wipe it clean, and apply another coat if needed.
Can I use a power sander between coats?
You can, but be very careful. Power sanders can easily remove too much material. For best control, I stick to hand sanding between coats.
