Flux core welding sometimes referred to as tubular electrode welding, is a technique developed from the MIG welding process. It is a type of arc welding that uses heat produced by an electric arc, which is struck between the work material and a continuously fed tubular electrode wire.
Flux core welding is effective in working with thick joints and is a versatile welding technique. This type of welding is frequently used in general repairs, shipbuilding, and other various forms of manufacturing. It is accessible as the equipment is relatively cheap to buy.
For pro flux core welding tips, here’s the ultimate guide on tubular electrode welding.
Prepare the Metal
Flux core welding is far more tolerant of surface contamination than MIG or TIG processes. Despite this, it’s best to ensure the surface of the metal base is cleaned thoroughly. While tolerance to contamination is useful, rust and dirt can still contaminate your weld.
Prepare the metal using a degreaser to perform an initial clean. Purchase dedicated metal brushes for different metal types and use these to complete the cleaning process. Make sure to clean the section of the base metal where the ground clamp is attached. This will eliminate potential resistance in the welding circuit.
For thick metals, you should bevel the edges. This helps create a total fusion for welds, particularly for butt joints. By reducing the thickness, it’s easier to develop a strong initial weld that you can build upon.
Set Up the Equipment Properly
One of the most important flux core welding tips is to get to know your welder. In flux core welding, you must use a DC electrode that’s set to negative. This setting is called straight polarity, and it can be adjusted by connections located on the inside of the welder, beside the drive rolls.
Before you start any welding project, make sure to check the cables. Examine the connections to confirm that they are tight and aren’t frayed. Look out for sparks or any damage.
Standard drive rolls may become damaged during flux core welding. Knurled drive rolls are better suited as the flux core wire is softer than solid wire. Ensure that your welder is fitted with these.
Test the wire tension on the drive rolls and wire spool hub. Ensure the tension matches the recommended level from the owner’s manual. This will encourage optimal wire feeding during use.
Carry out proper maintenance by getting rid of excess spatter from the contact tips, replacing contaminated or worn contact tips, and removing the wire if it becomes rusty.
Wear Safety Clothing
No matter what type of welding you’re doing, safety should always be a priority. The best way to protect your eyes, face, and body is through safe clothing and equipment.
A quality helmet shields your eyes from potentially harmful UV and infrared rays. It also prevents sparks and hot splatter from burning your exposed skin. Determine whether you need a variable or fixed shade lens as this has a big impact on price. Switching speed, power source, weight, and design should also be considered. It’s recommended to wear safety glasses beneath your helmet.
Welding gloves protect your hands from sparks and extreme temperatures. Flux welding, in particular, requires welders to wear gloves made from very strong materials. Leather from cowhide, elk, or deerskin provides an excellent core material. When combined with Kevlar thread, these gloves can provide an exceptional level of heat protection.
Avoid cuffing or rolling your clothes, and invest in a sturdy pair of work boots. You may also be interested in specialized welding sleeves, aprons, or jackets.
Choose the Right Wire
Flux core welding often involves using mild steel. Using a versatile wire is one of the best flux core welding tips that one can get. It can be used in various positions and is available in a range of sizes. When choosing the wire diameter, .030” is effective for general-purpose welding applications.
If you work mostly with thick materials at high heat levels, you should increase the diameter. .045” is the maximum diameter for powerful output welders.
Setting the Voltage and Amperage
It’s important to set the right voltage and amperage for your specific project. How much it requires is dependent on the thickness of metal, joint configuration, welding position, and wire diameter.
An experienced welder may know instinctively what’s necessary. However, there are reference charts and online calculators available to help establish the correct voltage, amperage, and feed speed.
Ensure You Have Adequate Ventilation
When welding in confined areas, you must ensure you have adequate ventilation. Welding processes involve several different toxic materials and gases. These can combine to become very dangerous if inhaled.
In potentially harmful atmospheres, using monitoring instruments helps detect danger quickly. If you can’t set up proper ventilation in your workspace, you can use air respirators or masks for breathing clean air.
Always Drag in Flux Core Welding
Dragging refers to a pull technique, where the tip of the welding machine is pointed toward the weld pool and dragged away from the completed weld. Dragging the torch ensures splatter compiles on the completed weld, minimizing porosity issues.
Pushing the welder can cause slag to develop in your weld puddle, creating a dirty weld. A good rhyme for remembering this technique is: “if there’s slag, you must drag.”
Learn Your Work and Travel Angles
Work angles refer to the welding gun position in relation to the welding joint plane—these change depending on the welding position and joint configuration. For example, a butt weld is a 180° joint. The gun should be held at a 90° work angle. For a T-joint (90°), the welder should be held at a 45° angle.
A travel angle is in relation to the angle of the welder when it is held in a perpendicular position within the plane of the weld joint. In general, travel angles are between 5° and 15°. Travel angles over 25° can cause spatter, arc instability, and a lack of penetration.
Learning work and travel angles ensures more even welds and helps avoid undercuts.
Flux core welding is a difficult skill and involves a lot more than knowledge. It requires hours of practice and dedication to perfecting your welds. With time, welders will learn the best approaches to projects, as well as potential issues to look out for.
Equipment and preparation are key. Prepare adequately by cleaning the metals and checking your equipment. Prioritize your safety and get to work. There are endless amounts of projects to take on.