Effective way to remove old, damaged paint or colored layers

You may need to combine several different methods to accomplish this task correctly. Read the various methods explained here and use the best combination of methods for your coating project.
â—† Scrape Whether it is smooth cement stone and hard fiber board, wood or ferrous metal, scraping is the most effective way to deal with flat surfaces. Make sure that the scraper is sharp and applies evenly when scraping in one direction; then scrape it at a 90-degree angle. The triangular or elliptical blade is more suitable for scraping corners and round surfaces. When scraping the hardboard, be careful not to apply force. For very hard surfaces such as hard or metal surfaces, double-handle scrapers can be used.
After the scraping is completed, use the medium size (#100) sandpaper to thin the remaining edges of the paint film.
Wear eye protection or masks to protect your eyes. Protect your skin with leather gloves or work gloves. Use a gas mask or respirator to avoid inhaling excessive dust.
â—† Wire Brushes On brick, cement and other stone and wood cracks, use hard metal hand brushes (brushing in the vertical direction). Power wire brushes are only suitable for areas that are difficult to handle and must be used with great care. Wear eye protection or masks to protect your eyes. Protect your skin with leather gloves or work gloves. Use a gas mask or respirator to avoid inhaling excessive dust.
â—† Grinding The scraped surface should be smoothed with sandpaper. When the substrate is wood or steel, dynamic grinding tools such as electric belt sanders can be used. Do not try to power cement stone, hardboard, aluminum or plastic.
â—† Power flushing The high-pressure clean water flow from the surface of 15 to 20 cm removes the old, loose paint film. Do not use harsh cleaning agents or bleach! Always spray at a horizontal or downwardly inclined angle. An upward angle will damage the siding. Since the jet may break the glass and damage the sealed area, be careful when flushing the area near the door or window. Do not perform power flushing on cork surfaces such as cedar or redwood. Wear goggles and waterproof clothing and boots.
Chemical Elimination Strong solvent scavengers are effective for most oil paints and latex paints, primers, stains and varnishes. Chemical scavengers can only be used in small areas where the surface is facing up, such as decorative borders and decorative lines. Make sure to choose the right chemical scavenger for your application. Follow the following points carefully:
- Allow children and pets to leave the area and remove all sources of ignition before use.
- Cover the floor and steps, and remove plants, carpets and Furniture.
- Apply a thick layer on a small area (approximately 0.2-0.3 square meters) with a cheap natural bristle brush.
- Allow sufficient time for its role (see manufacturer's recommendations).
- Carefully remove the softened paint film with a putty knife or wood knife and scrape them into cardboard boxes.
- If necessary, reapply more scavenger.
- Use a paper towel to clean the surface. Do not use steel wire to avoid surface fading.
- After completion, carefully dispose of waste according to the manufacturer's recommendations.
Note: Wear goggles or dust masks and long-sleeved shirts and trousers. Wear chemical-resistant gloves and chemical-resistant respirator. Follow all instructions and safety warnings. Some products are highly flammable and all fire sources must be completely removed before use.
There are also some odorless solvent-type scavengers, but because they are not strong enough to remove, they take longer to work.
â—† Heat Guns Heat guns designed to remove paint film - not propane guns or torches - are a good way to remove old exterior paints and varnishes. Follow these steps to work safely and effectively:
- Spread a layer of rags throughout the work area.
- Spray the rag regularly with a rubber hose to keep it moist.
- Spray a layer of water on the paint film with a heat gun.
- After the old paint film foams and becomes soft, carefully remove the paint film with a putty knife and place them in a metal container for processing.
Note: Wear goggles or masks and long-sleeved shirts and trousers. Use chemical-resistant gloves and respirator designed for use with heat guns. If you suspect that the old paint film contains lead, do not remove it with a heat gun. High temperatures can lead lead gasification, which will seriously harm health.