When you're working with any kind of metal in construction, you need to be sure that the surfaces are properly prepared for any kind of paint finish. Leaving the metal unfinished will lead to exposure damage, like rust and corrosion. One of the best ways to ensure that every surface is clean and ready for paint is through blasting. However, for the blasting process to be successful, you need to choose the right media for the job. Here are a few tips to help you select the media you need for the best possible results.
Strip Existing Paint with Aluminum Oxide
If there's any residual paint, oil, or other particles on the surface of the metal, aluminum oxide can strip it away. Just make sure you only use it on harder metal surfaces because aluminum oxide is hard and sharp. That means it will cause pitting in the metal if you use it on something that's too soft. The typical steel used in construction should hold up to aluminum oxide quite well.
Polish Surfaces with Glass Beads
If you are going to seal some of the metal against the weather without covering it with paint, consider using glass beads for the blasting in those areas. The surface of the glass beads will polish the metal without causing damage so you get a shiny, smooth finish.
Address Heavy-Duty Situations with Carbon Steel
If you're dealing with some particularly heavy steel surfaces and no other blasting media is cleaning it up, using carbon steel grit or shot will typically do the trick. The shot media is usually rounded, so it's best for surface polishing while the grit is more angular, making sharp edges for stripping rust and paint.
When All Else Fails, Go Softer
If you're torn between several different types of media, and you're not really sure what the metal will handle, opt for the softest one that you can. For example, when you're dealing with metal, things like baking-soda blasting will be the least abrasive while still getting the job done. Since it isn't particularly abrasive, you shouldn't have to worry about having pits and other flaws in the metal when you're done.
Any time you have blasting to do for surface preparations, the right media is essential. With these tips, you'll be able to keep your construction project rolling by choosing the best media for the surfaces you're working with.