Paint runs develop when excess paint drips from your brush, creating bumps in the finished coat. This process fixes runs that you discover once they are almost dry or completely dry, after it is too late to just wipe them away. You need paper towels, 220-grit sandpaper and a sharp razor blade or scraper. It takes about 15 minutes to eliminate a paint run and repaint the area.
- Blot or scrape the drip
You can blot a drip that is still partially wet to remove the excess paint. This smooths the area but still leaves a mark that needs to be repainted. If the drip is dry and hard, use a sharp blade or scraper to remove the bump. Work gently to avoid damaging the wall.
- Sand the area
Use 220-grit sandpaper to smooth the area. Wipe the sandpaper in the direction that the drip ran; do not move the sandpaper up and down. Work only on the drip's location, and keep the sanded area as small as possible. Use paper towels to wipe away the dust after sanding.
Apply another coat of paint to the marked area, and allow it to dry. If the mark is still visible, add a second coat.