TIG welding is a popular arc welding process that relies on the use of noble gases such as argon to complete a strong weld on a variety of metals. If you are going to be welding with one of these noble gases, you will need cylinder-argon. This term refers to argon that comes in a pressurized cylinder that can be hooked up to welding apparatuses. These cylindrical canisters come in a variety of sizes, from large canisters designed for use in heavy welding operations to small canisters that are suitable for the welding hobbyist. These tanks may be refillable, helping to increase cost efficiency in a welding operation. There is a vast inventory of cylinder-argon on eBay, including both cylinders and associated accessories such as gauges, wall brackets, and meters that are all useful in a welding shop setup. The canisters that are available in this inventory may be empty or full, with the empty tanks typically available for a lower cost than those that are full of argon.