MIG welding machines handbook: how to become a better welder and how to pick the best welding equipment. The arc is shaped like a cone, with the tip at the electrode and the base on the metal being welded. The closer the electrode is held to the metal, the smaller the base of the cone — but as you pull the electrode farther away, the base (and puddle) gets larger. If the puddle gets too large, gravity will simply pull it away from the base metal, leaving a hole. This is why thin-gauge metals are especially challenging for beginners. Perhaps the most important skill needed for TIG welding is moving the torch in a controlled manner, with steady forward movement, while keeping the gap between the tip of the electrode and the base metal consistently small — usually in the range of 1/8 inch to 3/16 inch. It requires a lot of practice to precisely control the arc length, keeping it as short as you can without allowing the electrode to touch the base metal or filler rod.
One of the “cardinal sins” that almost every shop commits is over-welding. This means that if the drawing calls for a 1/4″ fillet weld, most shops will put down a 5/16″ weld. The reasons? Either they don’t have a fillet gauge and are not exactly sure of the size of the weld they are producing or they put in some extra to “cover” themselves and make sure there is enough weld metal in place. But, over-welding leads to tremendous consumable waste. Let’s look again at our example. For a 1/4″ fillet weld, the typical operator will use .129 lbs. per foot of weld metal. The 5/16″ weld requires .201 lbs. per foot of weld metal – a 56 percent increase in weld volume compared to what is really needed. Plus, you must take into account the additional labor necessary to put down a larger weld. Not only is the company paying for extra, wasted consumable material, a weld with more weld metal is more likely to have warpage and distortion because of the added heat input. It is recommended that every operator be given a fillet gauge to accurately produce the weld specified – and nothing more. In addition, changes in wire diameter may be used to eliminate over-welding.
Several advices on welding equipment, MIG and TIG welders, plasma cutters. ARC Welding : ARC welding is one of the oldest welding processes around. It uses either an AC or DC power supply to create an electric arc between the welding rod and the workpiece metal to melt the metals and join them together. This style of welding is relatively inexpensive and very portable but it does require some practice to get good consistent welds and the welds will probably require some arc weldercleaning up afterwards. ARC welding is less suited to welding thinner materials but there is a large range of specialist electrodes (welding rods) available for ARC welders depending on what materials you are welding. ARC welding is versatile but more suited to heavier applications.
Flat-Position Welding Increases Welding Speed : It’s common knowledge that welding in a horizontal position will be the easiest and fastest way to weld. A flat position is not as taxing to maintain and the welding puddle will stay in place. Take some time to evaluate each project before beginning in order to make sure the majority of welds can be completed in this position. If a job calls for vertical welding, see this article about vertical welding. Core Wire Feeder Increases TIG Welding Speed: For professional welders hoping to speed up TIG welding, a core wire feeder will add filler metal through an automated process. Watch this video on how it works. This enables welders to work with both hands and to maintain a constant flow of wire into the welding puddle. Ed Craig at the Frabricator writes about the wire feeder process first developed in Europe, saying it is “suitable for all-position welding on materials of any thickness, the process addresses traditional GTAW limitations and can enhance both manual and automated TIG weld quality and productivity.” See more info at https://www.weldingsuppliesdirect.co.uk/welding-equipment/mig-welders.html.
Don’t use too much torch gas when welding aluminum on A/C. Don’t use too much torch gas when welding aluminum on A/C. Aluminum takes a lot of amperage to weld. Even though the melting temperature of aluminum is less than half that for steel, it takes about twice as much amperage to weld. Why? Because aluminum conducts heat away from the weld puddle faster than you can put it in. this brings me to an important point. Do not use more argon than necessary on your torch gas. If you do, it will be like blowing cool air on something you are trying to heat up with a torch. All that argon blowing on the part makes for a loud erratic arc because the arc force is so great. Have you ever lit up on a thick aluminum casting and listened to how loud the arc is? I bet your torch gas was up around 20 like the books recommend. That’s too much for aluminum (unless you are using an argon helium mix).