The Sandblasting Basics

Sandblasting is a process that involves forcing solid particles at high speed using compressed air onto a surface to smooth, etch, or clean a hard surface. The systems used to sandblast surfaces have four main components: the air source (usually an air compressor), the sandblasting blast pot, the basting media, and a dust collector.  We use a large booth to house our blasting system, with the dust collector to clear the air in the room during blast operations.

Safety precautions when sandblasting.  Sandblasting operations require specialized safety gear to protect the operators.  First is high quality hearing protection, blast goggles to protect your eyes, and either a blast mask or blast supplied air system.  The blast mask has a filtering system to provide safe air to the operator, and the supplied air system provides a supply of fresh air through a blast hood and helmet.  Heavy duty gloves and a blast suit, apron or similar clothing will help protect the operator from ricochet.  Steel toed boots are also recommended to protect from heavy objects that might land on your feet.

After Sandblasting
Before Sandblasting

Sandblasting has existed for years, and for good reason.  If you have rust or paint to remove, a new steel surface to profile for coating, weld slag or discoloration, or a piece of machinery or equipment such as a cement mixer, a car haul flatbed or a bulldozer to repaint, sandblasting is the fast and effective method to prepare the surface.

First, we should clear up the question of sand.  We don’t use sand, don’t even stock it, when we talk about sandblasting we actually mean media blasting, as we primarily use the mineral garnet as our blast media of choice, but we also use crushed glass, baking soda, corn cob, aluminum oxide, walnut shells, starblast, coal slag and plastic beads, among other types of media. 

Before and After – Paint Removal

There are two broad basic uses for sandblasting.  First is removal of some type of contamination, such as paint – failing paint, wrong color or type of paint, rusted surfaces, concrete or tar on a surface and similar substances that exist on a surface.  The surface is usually steel, but can be iron, aluminum, or other type of structure. 

The second use is to prepare a surface for a coating, such as epoxy, paint or powder or e-coating.  It is often the case that the surface needs both types of basic use, removal of the old failing paint and the profiling of the surface for better adhesion of the new coating.  Steel with a profile offers much better coating adhesion since the profiled surfaces has a way to lock the coating to the tiny “peaks and valleys” of the blasted surface which improves the effectiveness of the coating by improving the durability of the coating. A corollary to this use is the customer who desires a uniform surface for cosmetic reasons but is not going to apply another coating after blasting.  This is usually stainless steel or aluminum, which don’t rust, where they need to remove weld marks and hide that removal by blasting the entire surface to look the same, or where they designer wants a profiled surface for appearance reasons.

There are other uses for sandblasting, such as etching or artistic uses (think of mugs or mirrors with etched sayings or names on them), but in the industrial blasting world, 90% of our work falls into the categories of removal of a material on the surface and preparing a surface for a coating.

Sandblasting provides fast and reliable surface preparation for many hard surfaces.  Indigo has industrial blasting experience that makes us experts in the use of all types of blast medias, on hundreds of different types of substrates, all to provide our customers with the results they need for improving their products.

Types of dry blasting media