Sandblasting

Step by step instructions showing you how to sandblast a hand cut bottle, presented by Crafty Corner

What you need:

Sandblasting booth
Compressor
Sandblasting gun
Sandblasting sand (120 micron or better)
Hand cut glass
Particle dust mask
Artwork

Notes:

The compressor that you are you are going to use needs to be able to handle a minimum constant pressure of nothing less than 3bar (300Kpa) this would only be achieved with a machine that can handle at least 300l/min air flow or around 2.5 – 3 Hp.

Step 1

There are many ways of sandblasting a design onto the glass or you can simply sandblast the entire glass. Should you choose to be more creative, you can use mediums such as vinyl cut outs, steel stencils (the benefit of steel is that it can be used more than once) or hand cut vinyl stickers to make the design come alive after sandblasting. Most art stores also have a variety of stencils which can be used for sandblasting. Be sure to select a stencil made from a durable material such as plastic or vinyl, if you use paper, the sand in the blaster will simply cut through the paper, literally from the first use.

This step by step presumes you have a sandblaster, however we will briefly cover building your own basic sandblasting box. You will of course, need a compressor, as well as the sandblasting box. Buy yourself a large plastic container with a lid that can be tightly secured. If possible, the container should be 150l or bigger (see image below).
DIY Sandblastign box
Image from AR15.com

DIY Sandblasting Box

You will need to create two holes on the side of the container, these holes need to be large enough for your biceps to fit through. You need to have flexibility of your arms and hands once you start sandblasting, so ensure the distance between the two holes allows for this. Once you have measured the distance to suit your arms, mark the two holes and map off the circles. Drill a hole big enough to fit a jigsaw blade through and cut the two circular holes. It would be beneficial to line the freshly cut holes with a stretchy type fabric. Use silicone to keep the fabric “arms” in place. This will help reduce any sand leakage whist blasting.

Next mark of a small square area on the top of the box, this will create a window. It is essential to see what your hands are doing inside the box while you are spraying. The window should be as small as possible but still give you good visibility and light. You can choose to shape your window in a rectangle as well. This particular step is entirely up to you. Just remember that once you start sanding, the window will be affected by the sand being blasted. On the box I built, I also added a computer fan. (See picture). Once you start sandblasting the inside of the box gets very dusty, very fast and visibility is limited. The computer fan will help in this regard. You are almost ready to start sandblasting. It is difficult to find Silica Carbide in small quantities, so I opted for Silica sand used for children’s sand pits. I find the sand works best if it’s dried property and then sieved through a fine kitchen sieve.

Note: Because you are working with Silica, make sure you have a good quality particle mask to protect your lungs.

Step 2

Making sure you have your stencil firmly in place, you can now attempt to sandblast your glass. It is better to hold your glass a little further away from the nozzle. Hold the glass approximately 5cm away from the nozzle. We would suggest you start by sandblasting the bottom of the glass, making sure you have an even look once you have completed the base.

Step 3

Now, rotate the glass so that it rests lying sideways in your hand. Keeping the glass steady, using a painting motion, move slowly from the bottom of the glass to the top of your glass making sure you have an even distance from the nozzle at all times. Once you have gone in an upward motion over the glass, you will see the glass changing colour, following that line, now spray downwards towards the base of the glass, making sure you keep your spray even in both directions. Rotate the glass slightly so that you have a new spray line and repeat this step until the glass is evenly finished.

Step 4

It is important to check the quality of your spray before you remove any stencils or vinyl stickers. Once you have finished blasting the glass, use a cloth (damp if needed) to gently wipe surface. This will allow you to check the quality of your work. If you see any shiny areas, you’re not done. Remember: Once you remove your stickers or vinyl, you cannot always get them back in place and you will end up having a mediocre glass with shadows or smudge patterns. You cannot overspray a glass, so rather be thorough. If you have any doubt, re-spray the glass before removing and stencils.

Step 5

Once you are happy that you have an even spray over your glass, remove the stencil or vinyl, wash and dry you glass.