How to Strip and Remove Powder Coating – A Complete Guide
When it comes to powder coating proper preparation is critical. If the surface has an existing powder coating on it, it is best to remove that powder coating prior to reprofiling the part and wiping it clean to apply a new coat of powder coating. This guide will cover the different ways you can strip and remove powder coating, the pros and cons of each, practical tips on when each method may be best, and general tips on how to perform each method of stripping and removing powder coating. Will start with the 3 options to remove powder coating and the pros and cons of each.
Option 1 to remove powder coating – Sandblasting
Sandblasting can be an effective way to remove powder coating but does have some limitations as well. The pros of sandblasting to remove powder coating include that you do not have to deal with expensive disposal fees like you may if using chemical strippers. Additionally, sandblasting will create a profile while you remove the existing coat of powder, which can reduce the two common steps of removing powder coating then profiling and cleaning a part to just one step of stripping any existing powder and profiling the product surface. Sandblasting is also usually cost effective as the blast media can usually be used a few times. There are a few potential drawbacks to sandblasting compared to chemical stripping or batch burn off ovens. First, sandblasting can be harder to remove powder coating quickly if you have a lot of recessed surfaces on your parts. Second, for occasional removal of powder coating sandblasting may not make sense because of the equipment you need (unless you want to consider outsourcing the work). Third, to truly benefit from media savings and reduced disposal fees relative to chemical stripping, you typically need a sandblast room to be able to easily reuse your media which means your room will need to be big enough to hold your largest parts. Finally, sandblasting can take a bit more time than batch burn off ovens.
Sandblasting offers the best option for prep and powder coat removal in a single step. It can also be one of the most effective options for job shops and batch work when you need to remove an existing powder coating.
Option 2 to remove powder coating – Chemical Stripping
Chemical stripping involves using chemicals like an aircraft stripping agent to remove a powder coating. The benefits of chemical stripping include that it can be quick as you can wash the part down with a stripping agent or wipe it down. Additionally it is effective at removing powder coating from recessed and fine areas easily. Finally, it can be easy to do for occasional part needs as you can purchase a small quantity of stripper relatively inexpensively. The limitations of chemical stripping for powder coating include the hazards of the chemicals that you use, the potential difficulties to dispose of the chemicals, and that you will typically need to use another set of chemicals to etch the surface to prepare for a new coat of powder coating to be applied. Chemical stripping is typically best for infrequent stripping of powder coated parts or for excessive recessed areas.
Option 3 for removing powder coating – Batch burn off ovens
Batch burn off ovens use high heat to burn powder coating off a part. This method is one of the fastest options available, it deals with recessed areas easily, and doesn’t have issues with disposal fees. However the limitations to batch burn off ovens for removing powder coating include needing a large enough oven to hold any given product, which can require a large initial investment and can require large gas volumes to run which may not be available everywhere. Additionally, ith a burn off oven you still need to prep the surface to be able to re powder coat it. Batch burn off ovens are one of the fastest and most effective ways to remove powder coating and if you will regularly need to remove powder coating quickly can be a great option, they are also best for high production as they can be placed in a line with a powder coating wash system.
Practical tips on using each method
Sandblasting for powder coating removal
If you will be sandblasting to remove powder coating, you will want to use an aggressive blast media like aluminum oxide or steel grit. These medias will help reduce how long it takes to remove the powder coating. You want to be sure you have a large air compressor as compressed air is critical to production in sandblasting. Below are a few additional helpful resources you can review for additional information on sandblasting effectively.
Chemical stripper for removing powder coating
To remove powder coating with a chemical stripper you want to liberally brush the stripper on the surface. You will also typically need a way to brush off any residual powder coating that can be left on the surface. You want to use a proper respirator and prior to using chemical stripper will want to learn how you will need to dispose of the chemical.
Batch turn off ovens for removing powder coating
The key to a batch burn off oven is to be sure it provides a high enough temperature to properly bake off the powder coating, which can often be 1600 degrees.
Final thoughts on removing powder coating
In general when it comes to removing powder coating for job shop and batch work sandblasting can be a great option as it is cost effective and can reduce the number of steps needed prior to powder coating a part. Chemical stripper is usually best for infrequent occasional powder coating removal. Batch burn off ovens are one of the fastest and most efficient options to remove powder coating are often the most expensive, they are usually used I high production settings or where high volumes of product must have powder coating removed.