A complete guide on how to remove powder coating
Whether because of a coating failure, the need to update and refinish, or cleaning racks and hangers, sometimes you need to strip a coating. Though its durability is one of its greatest strengths, it is possible to remove powder coating from a substrate without destroying it in the process. You can remove powder coating with a chemical stripper, abrasive blasting, or extreme heat. There are even lasers designed to remove coatings. Here we will go through the three main methods to remove powder coating, outlining the pros and cons of each, followed by a guide to removing powder coating at home.
1. Chemical stripping
There are a range of chemical strippers available to remove powder coating from a substrate, each with a different application. There are hot and cold chemical stripping methods. Hot strippers are used like a caustic bath, kept at 175°F. The coating will soften, dissolve, swell, and then fall off, or be washed off. Cold chemical strippers are usually solvent-based and can be applied with a brush or in a bath.
Chemical stripping is relatively fast and economical, and it will leave you with a uniform surface to your substrate once the coating is removed. If the part is more delicate, chemical stripping can be the the only way to go. The downside of chemical stripping is that the environmental, safety, and disposal issues often outweigh the benefits. They also do not provide a surface profile on the substrate (like sandblasting), which may be necessary if you intend to reapply a coating.
2. Thermal stripping
Powder coating can be removed by the application of heat through a bake-off, burn-off, or fluidized bed stripping system. The heat breaks down the coating until it is just an ash residue, which can be removed by water or blasting. The substrate needs to be able to withstand the temperatures required to destroy the coating, which can be as high as 1200°F.
- Bake-off stripping systems: These are batch processes in which parts, hangers, or racks are loaded into an oven heated to 650-750°F, which is the temperature point at which most powder coatings degrade and eventually ignite. After several hours only ash should remain, which will need to be washed off.
- Burn-off stripping systems: At 1000-1200°F, this method uses the hottest temperatures. It causes the coating to ignite quickly and burn off from the substrate (hence the name). It can as little as 10 minutes for this process. Water is once again used to wash away the ash.
- Fluidized bed stripping system: This system uses a heated medium such as sand to transfer heat to the part. The coated part is lowered into a fluidized bed of heated medium ( at 800°F), and as the coating breaks down the ash is removed by the medium that is causing it. The part does not require additional cleaning.
Using heat to remove powder coating is one of the fastest removal methods, and it does not have the disposal issues involved with chemical strippers. Like chemical stripping however, it will also leave the substrate without a surface profile, possibly causing issues with future coating application.
3. Abrasive blasting
Abrasive blasting uses an abrasive media such as sand, and propels it at high speeds at a surface in order to strip the powder away. As well as sand, glass beads, steel beads, dry ice, garnet, water and plastic are used. Aggressive blasting can remove the powder coating quickly, but damage the substrate, leaving it rough. A gentler blasting method will preserve the surface profile, though it does take longer. Abrasive blasting is done in a sandblast room or a sandblast cupboard, depending on the size of the part and the thickness of the coating being removed.
Abrasive blasting is the cheapest option of the removal methods, if your substrate is not out-sized or irregularly shaped. It is also the method that will leave the substrate with a surface profile. Abrasive blasting does take longer than the heat and chemical options, at a rate of about 30 seconds per square inch. It also requires the part to be washed prior to blasting as otherwise contaminations may become embedded in the substrate, compromising the integrity of the part.
Which is the right removal system for your part?
In order to determine the best option for your powder coating removal needs, you need to know your substrate, how you plan to use it, and what result you want from the removal process.
- FAST REMOVAL: If you want the job done quickly, thermal stripping may be the way to go. A burn-off system is the fastest option.
- LOW COST: The cheapest stripping option is abrasive blasting, though this depends on the job – larger jobs require longer time and therefore more work hours.
- DELICATE PART: If your part is delicate or will not withstand high heat, chemical stripping is the best option.
- POST-STRIP COATING NEEDED: If you are planning to apply a new coating and need a surface profile, chemical and heat stripping will need further substrate preparation, while abrasive blasting leaves a rough surface for further coating.
- LOW ENVIRONMENTAL IMPACT: Thermal stripping systems such as a bake-off system are usually fairly environmentally friendly. If environmental or health considerations are important, avoid chemical stripping.
- STRIP GREASY/DIRTY PARTS: If you have parts, such as engine or chassis parts, which are greasy or dirty and you don’t want the hassle of cleaning it, thermal stripping is the appropriate system. The grease and dirt burns away with the coating.
- ALUMINUM: Chemical stripping works for aluminum as it does not damage the underlying part.
- STEEL: Abrasive blasting works well for steel substrates, as does thermal stripping under controlled conditions. Chemical stripping is also applicable.
- WHEELS/RIMS: A combination of chemical stripping and sandblasting is often used to remove powder coating from wheel and rims.
Where to find powder coating removal contractors
The process of applying a powder coat begins with the proper preparation of the substrate, including a cleaning step. This means that if you need to remove a powder coating, the place where it was applied is often the best option, as they likely have the necessary equipment already. There are powder coating companies across the country, and we have prepared thorough breakdowns of the businesses in these cities:
If you would like any more information on how best to remove powder coating, or would like to be connected with businesses and companies in your area, our experts are on hand. Get in touch through our “request a quote” button and we will do our best to assist you with your project. If you are removing powder coating in order to recoat an item or part, our powder coating prices overview will guide you as to your best options.
How to remove powder coating yourself
The industrial powder coating removal processes outlined above will probably not help the do-it-yourself remover – it is unlikely you have a sandblast room out the back! To remove powder coating yourself, you will need to use a solvent or chemical treatment. As noted above, this can be some nasty stuff, so you need to take every precaution when using it. When removing powder coating at home you should follow these steps:
- Make sure your work space is well-ventilated, with a solid floor (a garage is a good option). Wear safety clothing, including gloves, goggles and a mask or air-purifying respirator. Have a surface prepared to place the item on during the stripping process, such as a drop cloth or cardboard.
- Spot test the item with the stripper. Leave the stripper for the time recommended in the instructions, then test the powder coat with a scraper. If the paint is still stuck fast, try another spot test and allow more time for it to work. If this works, move ahead, otherwise you may require a different product.
- Apply the stripper. Coat the part being stripped and leave it for the same amount of time that you previously determined was needed for it to work.
- Scrape the paint. Once the time has elapsed, use a bladed paint scraper to remove the paint and the solvent. Dispose of the removed paint carefully. Go over the part with an abrasive pad or steel wool to ensure that all the paint and solvent is removed.
- Wash down the part. Rinse the part with water and wash it down with detergent.
Products for removing powder coating at home
There are a number of chemical stripping products available for consumers. Prices are an indication and may be subject to change. If you would like any more information about removing powder coating, please contact us through the “request a quote” button!
|PowderStrip||PS-1L Powder Coating Stripper||$160 for 5 gallons|
|Rust-Oleum||Aircraft Remover||$20 for 1 gallon|
|Jasco||Premium Paint & Epoxy Remover||$30 for 1 gallon|