The cost to weld aluminum averages about $14 to $22 per pound. The type of metal factors into the overall cost of any welding project due to the cost of the materials and the expertise required to work with it. Some of the most common metals used by welders include:

• Magnesium alloy: $7–$16 per pound

• Low-carbon steel: $11–$12 per pound

• Stainless steel: $13–$15 per pound

• Copper/brass: $24–$29 per pound

• Cast iron: $38–$79 per pound

• Titanium: $60–$85 per pound

Welders use a variety of methods in their trade. Different types of welding are better suited for different purposes and contexts. For example, stick welding is a versatile form suitable for most metals and alloys. The most common types of welding include:

• Stick welding: $100–$1,000

• Metal Inert Gas (MIG) welding: $250 and up

• Tungsten Inert Gas (TIG) welding: $250 and up

• Gas welding: $150 and up

• Forge welding: $15–$25 per hour

Cutting round ductwork requires precision and the right tools. A duct cutter, specifically designed for circular ducts, is ideal. First, mark the cutting line on the duct using a measuring tape and pencil. Then, position the duct cutter's blade on the marked line. Apply steady pressure, rotating the cutter around the duct. The sharp blade creates a clean, precise cut. Alternatively, a reciprocating saw with a metal-cutting blade can be used for larger round ducts. Ensure the duct is securely held in place while making the cut to prevent slips and maintain accuracy.

Professional metal fabricators typically charge around $70 per hour, but the total cost of your project will depend on several factors. The largest cost drivers are the size, complexity, and design of the project, as well as the price and type of metal used. A good way to estimate the total cost is to multiply the cost of raw materials by four; typically, one-quarter of the total goes toward materials and three-quarters toward labor. Your geographic location can also influence costs, as labor and material prices vary by region.