How to Weld With a Flux Core Welder
Welding has a come long way since the early days of a heating metal red hot and forging it or hammer-welding it together. As years went on a gas torch was used to heat the metal and filler rod was added to join metal. Then electric arc or “stick welders” came about. After that wire welders were invented and it really brought the welding process down to the “average guy”. Wire welding is a process where the welder feeds filler wire from a spool and an electrical current causes the filler wire to arc and melt into the base material. This process is fairly simple but it still can be daunting for a beginner. We decided to cover the basics for welding with a flux core welder.
What is Flux Core Welding?
Wire welders can come in a few different styles with the most common being a Flux Core welder or a MIG welder. Often all wire welders are called “MIG Welders” but technically that isn’t correct as the MIG welding process requires an external shielding gas while Flux Core wire welding does not require gas. A flux core welder uses a welding wire that is covered with a flux that when it burns it creates the coverage or shielding needed to keep the molten weld puddle free of impurities in the air. Flux core welding is great for welding outside or remotely where bringing a bottle of shielding gas on site isn’t possible. It also is great for beginners or home hobbyist welders as it takes one factor (and cost) out of the wire welding process.
To begin Flux Core welding you need to obtain a welder that can weld flux core wire. Most entry level machines can flux core weld but not all can MIG weld also. The Eastwood 90 Amp Flux Core Welder is a great inexpensive entry level welder but it doesn’t allow the use of shielding gas to MIG weld. We suggest if you’re planning to grow into your welder you pick a MIG welder that can handle flux core wire as well. The Eastwood MIG 135 also works on 110V input and can do both MIG and Flux core welding. You will pay a little more up front but you will get more power and also the ability to weld with MIG wire and shielding gas.
Once you have a Flux Core welder you can load your wire. Flux core wire will have a silver color versus a copper color of MIG wire. This coating is what burns off and shields your weld. The smallest flux core wire you’ll commonly find is .035 wire and will be difficult to weld thinner materials like sheet metal. Once the wire is loaded and fed through the tip of the MIG welder torch you can clean off a spot close to where you’re welding down to bare metal to attach your ground clamp. A clean ground is extremely important and can cause performance issues of your welder if you don’t have a clean ground. Finally you can clean the area you need to weld down to bare metal. While the flux core welder will burn the metal and wire to bond them together it will weld poorly if you try and weld through old coatings, rust, or undercoating. We suggest using a grinder with a flap disc to clean the weld seam on both sides of the seam.
Finally you’re ready to weld. We suggest covering any surrounding areas you don’t want weld spatter on as Flux Core welding does put off more sparks and spatter than MIG welding due to the process. You can used a welding blanket to cover large areas or welding anti-spatter spray to cover hard to reach areas. Begin welding by keeping the welding wire approximately an 1/8″ or less from the welding tip and hover it just a 1/16″ above the metal before pulling the trigger. Once you pull the trigger look for the puddle to form and begin moving across the weld seam left to right if left handed or right to left if right handed. Technique plays a big roll in the welding process and you will want to practice on scrap metal for your first passes with a welder.
You can clean up the weld area after welding with a wire brush as there will be welding spatter and residue from the flux core wire burning. Don’t forget to spray primer on the areas you welded to seal them up from rusting quickly as a welded panel flash rusts easily.
You can get all of your welding supplies to begin Flux Core welding HERE.