Wear a face mask if handling extremely fine-grain silica sand. If inhaled, it can irritate the throat and lungs. Silica sand is available from online retailers. It is fairly cheap - small quantities shouldn’t cost more than 20 dollars. If you want to operate on an industrial scale, specialty retailers can offer competitive rates on large orders - sometimes lower than $100 per ton. If it is not possible to find sand sufficiently free of iron impurities, their tinting effect can be countered by adding small amounts of manganese dioxide. Or, if you want greenish glass, leave the iron in!
Lead crystal can contain up to 33 percent lead oxide; however, the more lead oxide, the more skill required to shape the molten glass, so many lead crystal makers opt for less lead content.
Quartz sand without additives becomes glass at a temperature of 2,300 degrees Celsius (4,172 degrees Fahrenheit). Adding sodium carbonate (soda) reduces the temperature needed to make glass to 1,500 degrees Celsius (2,732 degrees Fahrenheit).
The molten glass can be poured into a mold and let cool. This method was used by the Egyptians, and it is also how many lenses are created today. A large amount of molten glass can be gathered at the end of a hollow tube, which is then blown into while the tube is turned. The glass is shaped by the air entering the tube, gravity pulling on the molten glass and whatever tools the glassblower uses to work the molten glass. The molten glass can be poured into a bath of molten tin for support and blasted with pressurized nitrogen to shape and polish it. Glass made by this method is called float glass, and it is how glass panes have been made since the 1950s.
The precise temperature for annealing can vary based on the precise composition of the glass from as low as 750 degrees Fahrenheit to as high as 1000 degrees Fahrenheit. The rate at which the glass must cool may also change - generally, larger pieces of glass must cool more slowly than smaller pieces. Research proper annealing methods before beginning. A related process is tempering, in which shaped and polished glass is placed in an oven heated to at least 600 degrees Celsius (1,112 degrees Fahrenheit) and then quick-cooled (“quenched”) with blasts of air at high pressure. Annealed glass breaks into shards at 6,000 pounds per square inch (psi), while tempered glass breaks into small pieces at no less than 10,000 psi and usually at around 24,000 psi.
Even at the extremely hot temperatures reached in this method, it can be difficult to melt silica sand in a grill. Add a small quantity (about 1/3 to 1/4 of your sand’s volume) of laundry soda, lime, and/or borax to your sand before you begin. These additives lower the sand’s melting temperature. If you’re going to blow your glass, have a long, hollow, metal tube handy. If you’re going to pour it into a mold, prepare your mold beforehand. You want a mold that won’t burn or melt from the heat of molten glass - graphite works well.
Heavy duty oven gloves or mitts A welder’s mask A heavy duty apron Heat-resistant clothing
Heavy duty oven gloves or mitts A welder’s mask A heavy duty apron Heat-resistant clothing
Make sure the hose is secure and will not move - if it comes loose while you’re making your glass, you should not approach the grill if it’s extremely hot. Turn the vacuum on to test your hose positioning. An accurate hose will blow directly into the vent.
Hardwood (or “lump”) charcoal burns hotter and quicker than briquette charcoal, making it a better choice if it’s available. [2] X Research source
If you’re still not able to reach high enough temperatures, experiment with replacing the lid while introducing air through the vent.
