Sanding is a common method for removing exterior paint, particularly when preparing a surface for a fresh coat. Here's a breakdown of how to do it effectively:
Preparation is Key
Before you even think about the sander, take these steps:
- Safety First: This is critical! Old exterior paint often contains lead. Wear appropriate safety gear:
- Respirator: An N95 or P100 respirator is a must to avoid inhaling paint dust.
- Eye Protection: Safety glasses or goggles will protect your eyes.
- Gloves: Protect your hands from paint and dust.
- Protective Clothing: Wear old clothes or disposable coveralls.
- Lead Paint Testing: If the house was built before 1978, assume the paint contains lead unless proven otherwise. You can purchase lead paint test kits at most hardware stores. Proper lead abatement procedures are crucial if lead is present; consider hiring a professional.
- Surface Preparation:
- Clean the Surface: Wash the exterior surface with soap and water to remove dirt, mildew, and other contaminants. Allow it to dry completely.
- Scrape Loose Paint: Use a paint scraper to remove any loose or peeling paint before sanding. This will extend the life of your sandpaper and make the sanding process more efficient.
Choosing the Right Sander
Several types of sanders can be used for removing exterior paint. The best choice depends on the size and type of surface:
- Orbital Sander (Random Orbital Sander): A good all-around choice for most surfaces. The random orbital motion helps prevent swirl marks.
- Belt Sander: More aggressive than an orbital sander, making it suitable for large, flat surfaces where you need to remove a lot of paint quickly. Be cautious, as it's easy to gouge the wood if you're not careful.
- Detail Sander (Corner Sander/Mouse Sander): Useful for getting into corners and tight spaces.
- Hand Sanding: For small areas, intricate details, or to touch up areas missed by the power sander, hand sanding is necessary.
Selecting the Right Sandpaper
Choose sandpaper based on the condition of the paint and the desired finish:
| Grit | Use |
|---|---|
| 40-60 | Removing thick layers of paint, very rough surfaces. |
| 80-120 | Removing remaining paint after scraping, smoothing rough surfaces. |
| 150-220 | Final sanding, preparing the surface for priming and painting. |
Important Considerations:
- Start with a coarser grit to remove the bulk of the paint and then gradually move to finer grits to smooth the surface.
- Use sandpaper specifically designed for paint removal; it tends to clog less.
- Change the sandpaper frequently as it becomes clogged with paint.
Sanding Techniques
- Secure the Sandpaper: Attach the sandpaper to the sander according to the manufacturer's instructions.
- Start Sanding:
- Apply Light Pressure: Let the sander do the work. Applying too much pressure can gouge the wood or cause the sander to stall.
- Consistent Movement: Keep the sander moving in a consistent pattern, overlapping each pass slightly. For orbital sanders, a circular or back-and-forth motion works well. For belt sanders, move in the direction of the wood grain.
- Sand in Sections: Divide the surface into manageable sections and complete each section before moving on.
- Check Your Progress: Periodically stop sanding and inspect the surface to ensure you are removing the paint evenly and not damaging the wood.
- Dust Removal: Frequently vacuum or wipe down the sanded surface to remove dust. This will allow you to see your progress and prevent the sandpaper from clogging.
Post-Sanding
- Clean Thoroughly: Vacuum or wipe down the entire surface to remove all dust and debris. Tack cloths are effective for removing fine dust particles.
- Prime: Apply a high-quality exterior primer to the sanded surface. This will help the new paint adhere properly and provide a uniform finish.
- Paint: Apply two coats of high-quality exterior paint, following the manufacturer's instructions.
