Tech - The Basics Of Welding
Tackle your own metal repairs on your vintage Mustang project
Buying a Welder
As we mentioned, we’re concentrating on MIG welding for this story, as it’s the most popular welding process for automotive repairs and fabrication. It’s also one of the easiest forms of welding to learn. We’ll also briefly discuss TIG welding for those who like to work with aluminum and the plasma cutter for those situations where you need to cut metal fast and precise. We understand everyone has a budget limitation, but don’t buy a cheap welder. You’ll only be hurting yourself in the wallet, as you’ll most likely end up buying a better welder down the road. It’s okay to buy used equipment if it was taken care of and checks out. This is one of the few areas where it is best to buy name brand, as it is infinitely easier to find service parts and consumables for popular welders like Lincoln, Hobart, Miller, and others than it is something from a lesser available and known brand.
While we’d all love to have a shop full of welding and fab gear, generally starting off with a good MIG welder is going to get you pretty far with your project, especially if all you plan to do is weld in new metal to your Mustang project. TIG welders are great for aluminum fab work if you’re making your own oil pan or aluminum brackets, but otherwise isn’t critical for sheetmetal work. The same goes for a plasma cutter. Much of the bad metal you need to cut out can be done with a reciprocating saw, cutoff wheel, or even an air chisel, so you don’t necessarily “need” a plasma cutter. As such, we’re going to concentrate on MIG welder choices and just touch on other equipment that would be beneficial to rust repair and metal work as your budget allows.
MIG welders are available in several styles, including stationary, mobile, and even some with built-in power sources for remote job site work. For the typical home shop, we’ll concentrate on stationary and mobile units. Most small workshops can get by with a stationary MIG welder that you carry to the job location and set on the floor (optional rolling carts are available). These welders usually can be powered by 115-volt household current, making them easy to use anywhere around the house. The downside is often duty cycle, or the amount of time a welder can be used at a certain power level in ten minute increments. For example, if a certain setting says it has 70 percent duty cycle, that means the welder can be used for a solid seven minutes and then must be left to cool (with its internal fan on) for three minutes before being used again. For most welding where you’re placing a tack here and there and then a few one-inch stitches, duty cycle may not be a factor, but if you plan long stitches of welding, then duty cycle is something to consider.
Mobile welders have built-in wheels and a handle to allow easy movement around the shop, but due to their larger size and capacity they are often tougher to fit in smaller shops/garages and usually require 230-volt input voltage. So unless you have the proper wiring into your workshop space to power it, you’ll have to do some wiring upgrades to your garage. Or course, the duty cycle on 230-volt welders is higher as well. Lastly, the larger 230-volt welders allow you to weld thicker materials. If all you expect to do is automotive sheetmetal and raw material up to about ¼-inch, a 115-volt welder will suffice, but if you plan on welding thicker materials, like frame rails, crossmembers, and subframe connectors, then you should seriously consider the 230-volt machines.