Cutting rectangular ductwork requires careful measurements and the right technique. Use a measuring tape and pencil to mark the cutting lines accurately. Tin snips are excellent for straight cuts on smaller ducts. For more extensive or thicker rectangular ducts, a reciprocating saw with a metal-cutting blade is effective. 

Ensure the duct is well-supported and secure while cutting to prevent wobbling and maintain precision. After cutting, use a metal file to smooth any sharp edges, ensuring safety during installation. 

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.

It will likely take an experienced pro less than an hour to install a ground rod, which is another reason why letting them handle the job is such a good idea. Safety concerns aside, it would likely take you much longer to install a ground rod if you decided to take this one as a DIY job.

You should not do your own welding unless you have the proper training and experience. Most home electrical systems can only handle MIG welding, which creates weaker bonds than TIG welding and won’t work on certain metals or metal thicknesses. Both welding forms usually require the use of shielding gas, which can be dangerous to store at home. Additionally, welding machines create temperatures of over 3,000 degrees, and the sparks can blind you if you don’t have the proper equipment. As such, it’s usually better to hire a professional welder for your welding projects.