Mirror illusions have always been a unique type of entertainment. They leave your mind both…
Have you ever noticed the seamless etched designs that can be found on mirrors, windows and glass, and wondered to yourself how they were made? The most common method of adding texture to the surfaces of these pieces is through Abrasive Blasting. Sandblasting is one technique that can be utilized to alter the surface of glass. There are also a number of other blasting techniques out there you can choose to use outside of sandblasting. The majority of these methods are commonly used to alter a smooth surface to a roughly textured one, or to forcibly clean hard to remove contaminants from the exterior of the material being treated.
Curious to see how this type of work came to be, or how you can make something similar yourself? Keep reading to learn more behind sandblasting, the other methods out there, and how to use a sandblaster to create your own unique etched work.
The History Behind Sandblasting
Sandblasting first came into existence in 1870 when inventor Benjamin Chew Tilghman was inspired to invent his own sandblaster. There isn’t concrete evidence to support this next statement, but it is believed that Tilghman was inspired to create his invention after seeing the effects windblown sand had on windows in the desert during his travels as a Brigadier General.
Tilghman continued with his work in 1870 by patenting his work in the United States under US patent 108,404 as well as having it be patented in the UK. A year later, he was recognized with the “Great Medal of Honor” at the 40th Exhibition of the American Institute of the City of New York.
Tilghman’s sandblaster was just one of many inventions he worked on and patented over his lifetime. The majority of his work revolved around sharpening, engraving, and cleaning the surfaces of materials.
Sandblasting is just one of the types of Abrasive Blasting Techniques out there. Below is a comprehensive list of the other methods you can find to etch on glass, from most abrasive to least abrasive materials.
With each method, it is important to remember to stay safe when working, and be aware of the materials you are using. For some, these items can cause anaphylactic shock for individuals with specific allergies.
- Sandblasting – with this method, sand is used with an air compressor to treat the surface of whatever material you are using. It works similar to rubbing sandpaper over everything, but leaves an even finish throughout the surface of the glass. It is best to work with this in a well ventilated area since the type of sand used is silica sand.
- Shot Blasting – takes metal shot pellets that are used to treat harder materials like concrete or metal surfaces. The machine is loaded with beads, then has its surface blasted to remove debris and stains. This method is makes for easy cleanup in that it hardly leaves behind any dust.
- Ice Blasting – also known as wet-ice blasting or frozen-ice blasting, is a method that takes frozen water particles with an air compressor and propels the material onto the surface to clean it.
- Dry Ice Blasting – with this, air and dry ice are combined to dislodge contaminants on a surface by having frozen carbon dioxide particles hit the surface at high speeds. No cleanup is really necessary since the ice eventually dries and turns into a gas.
- Glass Bead Blasting – takes glass beads that are propelled at a high pressure to remove surface deposits without damaging the material. It is often used in auto shops to remove paint on vehicles, as well as on pool tiles to take off calcium deposits.
- Plastic Media Blasting (PMB) – uses ground-up plastic stock or natural materials such as walnut shells and corncobs. This is used to treat softer substrates like with deflashing plastic components, cleaning molds, waxes, adhesives and sealants.
- Sodablasting – uses baking soda (sodium bicarbonate) that gets blasted onto a surface with an air compressor. It can be used to treat cars, industrial equipment, as well as remove particles like rust or oil.
- Acid Etching – is done using hexafluorosilicic acid which is prepared by dissolving silica in a mixture of hydroelectric acid (hydrochloric acid), quartz powder, calcium fluoride, and concentrated sulfuric acid derived after heating.
- Glass Etching Cream – a simpler version of acid etching. You can purchase a solution online to start. Prep your glass surface for treatment by cleaning it, then apply the cream with a wooden stick (typically accompanied with your etching cream kit) over your design. Wait the allotted amount of time necessary for it to affect the glass. Then clean the cream off by wiping down your glass with window cleaner and allow to dry completely.
**WARNING: First Surface Mirrors can not be treated with acid etching techniques because it is not able to penetrate the aluminum layer on the surface.**
Safety with Sandblasting
You should always plan out safe working habits when using machinery built for sandblasting. Sandblasting uses crystalline silica sand, which can cause serious respiratory problems such as silicosis or possible death from silicosis. The current OSHA permissible exposure limit (PEL) for breathing in crystalline silica ranges from 8-10 hours of exposure time. To prevent yourself from getting hurt when working, follow these tips:
- See if you can substitute silica sand for something less damaging such as natural products like walnut shells which are less abrasive. If you need something that is more abrasive, try another method such as shot blasting.
- Put on safety glasses to protect your eyes from getting irritated from the dust that gets stirred up when the air compressor is in use.
- Have respiratory protection by wearing a face-mask while you work, preferably one with supplied air. (Here’s an explaining on the difference between Respirators and Dust Masks).
- Wear gloves, heavy boots and thicker clothing to protect your hands, feet and body from the materials that will get blasted back at you while working, especially if you do not own a blasting chamber.
How it all Works
Now that the safety methods have been covered, let’s explain how sandblasting works. For starters, it’s best to make sure you have the right tools to do your project. First and foremost, you’ll want to decide on the type of glass you want to etch onto. This website has an extensive variety of glass mirrors you can chose to utilize in your project. Our video is based on First Surface Mirrors, so we will be sticking to covering how to sandblast that type of mirror. Which isn’t too different from treating a regular mirror, it will just have variations on the types of visual effects you can achieve.
You only need a few things to get sandblasting underway: the material you’re sandblasting, your sandblasting machine, and the abrasive material needed to go into the sandblaster. Additional items include your safety gear, as well as a sandblasting chamber if your company or you yourself can afford one. These are excellent at protecting your hands and arms when treating your glass.
Sandblasting can be used for both industrial and artistic purposes. Here are the start your process:
- Grab your glass and place your design on the surface. This can be done by carving into the vinyl covering your glass, or if there isn’t vinyl, you can place tape over the areas you do not want treated and leave bare the areas you wanted textured.
- Put on your safety gear listed from earlier and take your design to your sandblaster.
- If you have a blast chamber, put the glass inside and center it, ensuring it is stable sitting on its own. Close your lid and ensure it’s securely shut before putting your arms through the built in rubber gloves.
- Turn on the sandblaster with the switch it has, and aim your nozzle at your glass. Start blasting about six to twelve inches away to ensure you get an even coating over the entire surface, making sure to get all those hard to reach corners.
- Once you’ve finished blasting your piece, turn off the sandblaster and remove your work from the blasting chamber. Take your piece and clean it with water, or take glass cleaner and a microfiber towel to wipe off the surface.
You can do further research on the specific types of abrasive techniques you are interested in using for your project, as well as see the additional types of sand and natural abrasive materials you want to use to blast onto your project’s piece.