What is Sandblasting?
Sandblasting is a general term used to describe
the act of propelling very fine bits of material at high-velocity to
clean or etch a surface. Sand used to be the most commonly used
material, but since the lung disease silicosis is caused by extended
inhalation of the dust created by sand, other materials are now used in
its place. Any small, relatively uniform particles will work, such as
steel grit, copper slag, walnut shells, powdered abrasives, even bits of
coconut shell. Due to the dangers of inhaling dust during the process,
sandblasting is carefully controlled, using an alternate air supply,
protective wear, and proper ventilation.
A sandblasting setup usually consists of three different parts: the
abrasive itself, an air compressor, and a blaster nozzle. For etching
and small object cleaning, a workstation to hold the piece of glass is
also needed, as is some sort of collector to gather up excess dust.
Sandblasting is primarily used for two somewhat different applications.
The first of these is to clean a surface of anything that may be
clinging to it. The second is to either etch or carve designs or words
into glass or a similar material.
The first sandblasting process was patented in the US in 1870. As a
cleaning method, it is often used for priming a surface for the
application of paint or a sealant. When painting, one doesn’t want to
trap dust, dirt, or bubbles in a previous layer of paint, or other
imperfections under the new layer. By launching small bits of abrasive
at the surface at a high speed, all imperfections are knocked loose and
can then be easily washed off, creating an incredibly smooth surface
upon which to lay the new layer of paint. Sandblasting may also be used
for such projects as cleaning the hulls of ships or large structures
such as the Golden Gate Bridge.
In decorating glass, sandblasting is a wonderfully popular technique,
with few substitutes. While hand-etching is possible, it is incredibly
time consuming and expensive, and laser-etching has a range of flaws
which make it a questionable choice. There are two main ways in which
sandblasting is used to decorate glass: etching and carving.
In glass etching, abrasive is blasted at the glass lightly to turn
the glass semi-opaque. This ‘whiting’ or ‘snowing’ of the glass can be
used to great effect to produce words or images. By adjusting the speed
of the sandblasting and the angle from which the abrasive is being
launched, differing shades can be created, allowing for some true works
of art. Glass is carved by steadily sandblasting the surface through a
stencil which protects the areas you don’t want to be carved out.
Sandblasting as a technique for carving can be very nuanced, with
differing depths and angles of cuts creating an array of lighting
effects that may be quite beautiful.
The cost of sandblasting equipment depends greatly on the scope of
the projects intended. A small home glass carving setup can be acquired
relatively inexpensively, while a system with a cabinet capable of
handling larger pieces of glass and more nuanced sandblasting can cost
significantly more. A professional-level artistic sandblasting setup
will likely be quite expensive. Industry-level sandblasting equipment
also varies in cost, again depending on the scale and scope of the
projects to be completed.
Source:
wisegeek
