Blasting or pretreating your surface is an essential step in the powder coating process. It ensures no contaminants on the surface before applying a new layer of material, which could lead to improper adhesion and reduced durability over time.
This guide will cover how it works, why you should be using it for your needs, and finally, provide some recommendations for blast media to use depending on what type of finish you’re looking to achieve.
How it works
Blasting is a process that uses an abrasive material to clean the surface of contaminants. It helps remove rust, debris and paint from the parts you want to coat with powder. It can expose any areas where there might be corrosion, so your next layer sticks better.
You can do blasting through an air compressor and special nozzle. The material used in the process can be sand, glass beads, or other small granular pieces. They get propelled out of a gun at high speeds using compressed air.
Blasting also prepares your part for other forms of coating or painting, including epoxy paint and urethane enamel. With any of these options, you will get better results. Don’t forget to use a Blast Booth for efficiency.
Why Use Blasting?
Below are the top three reasons for blasting.
1. Remove Contaminants
A key benefit of blasting is that it can remove any contaminant from the surface of your part. It will prevent further damage to your finish and ensure proper adhesion in future applications.
For example, if you’re using powder coating over an aluminium frame, but rust spots are present on the surface, that could cause an issue with the process. So, blocking out any possible contaminants before you begin will lead to a better outcome.
2. Prepare the Surface
Blasting can also prepare a part for coating by removing any signs of corrosion or damage. For example, if you have a bike frame painted in some places but not others, blasting it will ensure no rust. It will also make the powder stick evenly across all parts of your product.
3. Improve Surface Quality
Blasting can also improve the overall quality of your product by removing any visible blemishes or imperfections. That will ensure that the application of a new layer is even and smooth, which leads to an improved aesthetic over time.
What You Need to Know
Depending on the type of finish you want, your blasting media will vary. Most applications would use either glass beads or plastic media. The former is a good option if you’re looking for a smooth and glossy surface, while the latter will give you a matte surface.
If your parts are in less than stellar shape, glass beads might be the way to go. They can do a great job of smoothing out imperfections before applying powder. On the other hand, plastic media is a good option if there aren’t any marks or blemishes on your part. It won’t leave any marks, scuffs, or scratches.
As you can see, blasting is an essential step before applying powder coating to your parts. It provides a clean surface for the adhesive and removes contaminants so that you can ensure durability over time.