When newly applied, paint can apply an opaque sheen to metal components. However, it tends to degrade over time, resulting in a dirty-looking surface. Painting over it isn’t really an option, as any imperfections will carry through into the new coat as well.
Fortunately, there are ways to remove paint from metal without too much effort, leaving the surface as sleek as it was when it left the manufacturer. Choosing the best method will largely depend on the item being treated, so in this blog, the team atRed Label Abrasives will explain how to remove paint from metal without too much time, effort, or risk of damage.
Depending on the method you choose, you’ll need the following tools and accessories:
Surface protection in the form of plastic sheets, newspapers, drop cloths, or similar items
Disposable pan or pot
The paint scraper is ideal for flat surfaces and small jobs where the paint will come off without using chemicals. If you're working with a softer metal, such as brass, choose a plastic blade over a metal one to avoid damaging its surface. Choose a scraper that's comfortable to hold and suitable for the job (a wide blade for flat, wider surfaces and a narrow blade for smaller, difficult-to-reach areas).
For smaller items, boiling water can remove paint. Put the metal item in a heat-resistant container. In a kettle or teapot, boil water until it reaches a rolling boil. Pour boiling water slowly over the hardware, submerging it.
Wait until the paint begins to bubble before removing the hardware from the boiling water tray. In most cases, this will take about five minutes. (If the paint doesn’t bubble, drain the pan and repeat the process with more boiling water.) As soon as you notice the paint peeling off, put on heat-resistant gloves and carefully scrape off the loose paint while the hardware remains in the container. As a final step to remove dirt, grime, and tarnish, use a lint-free cloth.
Baking Soda / Vinegar and Heat
If you’re working with smaller items like hardware or door hinges, mixing baking soda and water or vinegar and water over a heat source is a natural way to remove paint from metal surfaces. This can be done on your stovetop with a disposable pan or pot. Add 1/4 cup of baking soda or vinegar to each quart of water and bring to a boil. Place the item in the pan and let it boil for about 15 minutes or until the paint falls off. Put on heat-resistant gloves and remove metal pieces with tongs. Use a hard-bristle brush or putty knife to scrape off any remaining paint.
Using a heat gun melts the paint, allowing it to peel off the metal. Put the heat gun on its lowest setting and hold it a few inches from the surface, moving it slightly back and forth. Start slowly and avoid overheating the area. When the paint begins to bubble or pull away from the surface, scrape it off with a paint scraper or putty knife. If the paint does not bubble, gradually increase the temperature until it does. Use heat-resistant gloves and wait until the metal has cooled completely before touching it.
If you’re working with more robust metal pieces like pipes, metal furniture, and larger flat surfaces, you can use an angle grinder to remove the paint.
The job can be accomplished using a variety of grinder attachments. Wire wheels are very effective, but they also throw off the most debris. Therefore, it's best to start with a less aggressive approach. Try flap discs, which are available in a variety of grits. Depending on the results, you can always switch to a coarser grit or wire. Red Label manufactures high densityEdgeCore Ceramic Flap Discs, which work great for removing paint and are some of the longest-lasting flap discs on the market.
Closed coat aluminum oxide, zirconia, and ceramic will all work for sanding paint off of metal. Ceramic delivers the most aggressive cut and the longest lifespan, so you’ll get your money’s worth when you use ceramic discs for metal sanding.
An angle grinder isn’t the only abrasive tool you can use to remove paint from metal. You can also use an orbital sander withmetalworking sanding discs. Orbital sanders are some of the most common tools used for sanding paint off of metal surfaces, especially for auto body work.
You can start with an 80 grit sanding disc for the initial paint removal, but you’ll want to switch to a 180 - 220 grit sanding disc once most of the paint is off. If you continue to sand with an 80 grit disc after most of the paint is removed, you can accidentally sand into the metal too much and weaken the workpiece.
You can use sanding sheets in combination with your orbital sander to sand tight spaces and corners. You can create a smooth finish on your metal after sanding by rubbing steel wool across the surface in a circular motion.
Paint stripper may be your best option for large metal pieces or those coated with spray paint. Before using this method, ensure that the area is well ventilated and that any potentially flammable items are removed.
Fill a glass or metal can with a small amount of the stripper. Chemical paint stripper should be applied to the metal using a disposable paintbrush, and let it set according to the instructions. You should see the paint bubble up from the metal surface as it sets.
Take a paint scraper and scrape off the bubbled paint from all the metal's flat surfaces. Switch to a nylon brush or scrubbing pad for crevices and harder-to-reach areas. The stripper should be reapplied and scraped or brushed away as needed until all the paint has been removed.
Next, dampen a rag with mineral spirits and wipe the surface to remove any leftover paint flakes and the bulk of any chemical residue. Finally, rinse the metal thoroughly with water to completely remove all traces of the stripper, then wipe it down with a fresh, dry cloth.
Tips for Better Paint Removal
You can use old toothbrushes to clean hard-to-reach corners and crevices.
Coarse grits below 80 and brushes with wire-bristled bristles should not be used on metal; otherwise, they may pit or damage the surface.
Follow the paint stripper's instructions and leave the chemical on the metal for the recommended amount of time.
Using mineral spirits and a clean rag, clean the item after all paint has been removed.
Ensure that paint, chemicals, and materials are properly disposed of.
Best Practices for Safety
Use the following safety measures when removing paint from any surface:
When working with a chemical paint stripper or angle grinder, make sure you are working in a well-ventilated area (outside, if possible).
When working with chemicals, wear gloves and a face mask to avoid potentially dangerous contact.
You can test your metal piece for lead if you suspect the paint contains lead (which is possible if it was applied before 1980). If the test is positive, protect yourself appropriately and use a removal method that wipes off the paint and disposes of it immediately, rather than grinding or dry scraping, which creates dust and airborne particles. It may be safer to call in a professional to remove the paint.
Red Label Abrasives: A Cut Above The Rest
When you’re working with larger metal surfaces, your best option may be to grind away any built-up paint. Red Label Abrasives manufacturesmetal sanding discs andflap discs that can remove paint without damaging the metal surface underneath. We also produce sanding belts, discs, sheets, and accessories that reflect almost four decades of experience in the abrasive industry, so if you need abrasives for general or specialty applications, we can help.
David Kranker is a writer and creative maker who has been covering the abrasive and knife-making industries on the Red Label Abrasives Blog since 2020. David spends his time continually researching sanding and bladesmithing to provide readers with the latest and greatest information. In his free time, David utilizes abrasives for many different home and auto projects at his home in Delton, MI.