Stone carving using garnet blast abrasives
Cutting Stencils for stone carving
When using garnet blasting for stone carving you can choose to use stencils that you cut out either manually or with a stencil cutting machine that does the hard work for you. If you are choosing a hand prepared stencil, apply the resist material to the stone material, draw your design out on the resist and cut out the parts to be etched with an extremely sharp knife like an xacto or box cutter. Machine cut stencils are most often done from a design on a computer with a vinyl plotter/cutter. A huge advantage to using an automatic machine cutter is the design is retained in your computer to be reused whenever you want and to be easily resized as you wish.
Different techniques are used to create different effects.
Surface etching is a single uniform blasting that produces a uniform texture.
Shading is a multi-stage blasting technique in which carving is done to create different depths of blast, shading is done to create different shades of blast effect ranging in tone from 0% to 100%. Whereas other blasting methods produce a black and white variation, shading creates varying tones of gray. A skilled sandblaster can create shaded designs that look very much like black and white photographs. Because the shading technique requires delicate control, it is usually done with reduced pressure and blasted from a greater distance than for surface blasting or carving. A pressure pot is especially useful to maintain a low but consistent blasting pressure. Some people prefer to use very fine grit for shading projects. This technique takes a lot of time and practice to master and is not for beginners.
Multi-stage blasting is the technique that creates a strong contrast by removing part of the stencil and blasting long enough to cut deeply into the stone material – then removing the rest of the stencil to surface etch the rest of the design. It can be done in as little as two stages, or as many stages as you want to try to obtain your desired effect. Because your objective is to create a strong contrast between the different parts, it is very important to spend significantly different time blasting each stage.
Virtually any design can be created using surface etching, multi-stage designs usually need to be specifically designed to be done as multi-stage etching. It’s important to plan a multi-stage design carefully so that you are blasting components in the desired order to create your desired effect.
Carving is when stone material has been blasted using garnet or other blast abrasives such as superoxalloy abrasives in variable curves to create contour. This technique takes a lot more time than other sandblasting techniques and takes a lot of time and practice to become skilled at. Carving is most often done at high pressure and from a close distance. For that reason it is especially important that you use a strong resist that will stand up to the aggressive blasting pressure needed to carve deeply into the stone material. Much like multi-stage blasting, carving requires careful advance planning to create the desired effect. Carving is designed to be viewed from the smooth side. This should be kept in mind when blasting your varying curves and depths to create contrast and perspective on your piece. When planning out your design, it is a good idea to flip it over before cutting the stencil for your project.
Choosing your abrasive for carving stone
Picking the right abrasive blast material for your stone carving project is an essential step in this process When choosing the right blast abrasive for your project it is important to remember the cost factors and reusability of your material, superoxalloy abrasives from 10X Engineered Materials can save you both time and money on your next stone carving project.
Currently, KinetiX and EpiX are available from abrasive distributors around the US. If you don’t see a distributor near you, contact 10X and we will work with you to get you what you need. EpiX abrasive, which is best for precision applications such as powder coating and medical applications, is also available to purchase directly from the 10X Engineered Materials website.