Posted by Patrick Moreau on August 10, 2019 in Shopping
A few advices on welding equipment, MIG and TIG welders, plasma cutters. MIG welders use a wire welding electrode on a spool that is fed automatically at a constant pre-selected speed. The arc, created by an electrical current between the base metal and the wire, melts the wire and joins it with the base, producing a high-strength weld with great appearance and little need for cleaning. MIG welding is clean, easy and can be used on thin or thicker plate metals. Similar to MIG welding, flux-cored arc welding (FCAW)* is a wire-feed process but differs in that self-shielded flux-cored welding does not require a shielding gas. Instead, flux-cored wire is used to shield the arc from contamination. This is a simple, efficient and effective welding approach, especially when welding outdoors, in windy conditions or on dirty materials. The process is widely used in construction because of its high welding speed and portability.
5 MIG welders tips: how to become a better welder and how to pick the best welding equipment. Use the smallest tungsten that will get the job done. Use the smallest tungsten to get the job done. …within reason. Another way of saying this is don’t just use a 1/8” electrode for everything. There are jobs where a 1/8” electrode is great like for welding 3/16” thick aluminum. But what if you are welding on the edge of a .030” turbine blade? A .040” electrode will be plenty to handle the 15 amps and will give much better starts than even a 1/16” electrode. Too large an electrode can cause an erratic arc and contamination…and A bad start where the high frequency tries to arc up inside the cup and off the side of the tungsten can easily melt off a thin edge and scrap an expensive part. 2% thoriated or lanthanated tungsten electrodes hold up at high amperage better than most all other electrodes. When welding at higher amperages, often times you can use one size smaller electrode by using 2% thoriated or lanthanated. And that is a good thing.
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. Searching for the best TIG Welders? We recommend Welding Supplies Direct & associated company TWS Direct Ltd is an online distributor of a wide variety of welding supplies, welding equipment and welding machine. We supply plasma cutters, MIG, TIG, ARC welding machines and support consumables to the UK, Europe and North America.
Get filler metal charts to let you choose correct rods for whatever materials you are welding: Alcotecs Aluminum filler metal chart . Go online to alcotec.com for an aluminum filler wire chart. You probably won’t find a filler metal chart that covers welding dissimilar metals so here is your filler metal chart right here: are you ready? Here it is… if it you don’t know what metal you are welding, but it sparks when you grind it, and it is not titanium, try using hastelloy W. or 312 stainless. Hastelloy W TIG welding rod has become extremely expensive. 312 stainless is also a very good rod choice for welding steel of unknown composition. For a critical weld, you should not just rely on 312 without knowing the metal type..you should determine the metal type for any critical weld.
The welding setup, welder settings, and electrode selection will impact how fast welders can work. Industrial welders invest time in planning the size and shape of their welding areas, how parts are laid out, and how they supply their shielding gas. Testing settings or an electrode on a piece of scrap metal, especially for a beginners, will save time in the long run. Learn more about setting up an efficient shop here. Welding Downhill Increases Welding Speed: While welding downhill is a faster way to weld, it’s not as strong as welding uphill. On most projects it’s not worth sacrificing strength and durability for the sake of welding speed. However, if the metal is thin enough, then welding downhill won’t make the weld weaker and may even be the correct technique for the job. Learn about uphill and downhill welding and see these diagrams of vertical and downhill welding.
Contact tips can have a significant impact on MIG welding performance since this consumable is responsible for transferring the welding current to the wire as it passes through the bore, creating the arc. The position of the contact tip within the nozzle, referred to as the contact tip recess, is just as important. The correct contact recess position can reduce excessive spatter, porosity, insufficient penetration, and burn-through or warping on thinner materials. While the ideal contact tip recess position varies according to the application, a general rule of thumb is that as the current increases, the recess should also increase.
Should the electrode accidentally touch the metal or the filler, the electrode often becomes contaminated — meaning some of the rod or base metal gets stuck to it. Once the electrode is contaminated, the arc cone becomes misshapen, making it difficult or impossible to aim the arc with precision, and the boiling contaminants on the electrode may spit out impurities, further compounding your problems. The angle between the torch and the base metal is important, too. You need to angle the torch slightly to see the puddle, and provide access for the filler rod. A 15-degree angle is a good starting place, although some welders prefer a bit more or less. If you hold the torch at 45 degrees (or more), you’re losing a lot of the coverage from shielding gas, and the flatter angle will make the puddle longer than it is wide. For the record, the torch is tipped with the electrode pointing forward, in the direction of motion. Source: https://www.weldingsuppliesdirect.co.uk/.