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How to weld (Arc)


Author: NJR Steel
Article Views:10937
Categories: Manufacturing, DIY

This article is intended to teach you how to use a flux cored arc welder. This machine is one of the most basic welders available on the market today and is known for being both user-friendly and cost-efficient. Although there are several limitations as to what you can get away with on this machine, it is a great welder for beginners and is perfect for doing non-structural, ornamental welding.

An example of a flux cored arc welder
An example of a flux cored arc welder

Step 1: Safety

The first and most important thing to consider while using any sort of welder is safety. Not only is the electricity required for arc welding extremely hot, but it also generates dangerous UV light that can easily damage your eyes if you look directly at it. This is why you should always use the proper Personal Protection Equipment (PPE) while working on your welding project. This includes, but is not limited to: safety glasses, leather welding jacket, welding gloves, and of course, the welding mask (also known as a welding hood). It also really helps if you have long pants and close-toed shoes. Flux Cored Arc Welding (FCAW) is known to generate lots of sparks that can easily burn any unprotected areas of your body, so cover up! These sparks can also easily start a fire, so any flammable materials should be kept at a reasonable distance from the welding area.

That being said, welding can be a fun and exciting way to make things out of metal and after a bit of practice, there is endless potential to make some really cool stuff. So, lets get started.

Step 2: Gather necessary equipment

Before you start welding, you will need to make sure you have all the tools required for the project at hand. The following list should contain everything you will need over the course of your welding project:

  • Safety glasses
  • Welding mask
  • Gloves
  • Leather jacket
  • Ear protection
  • Pliers
  • Chipping hammer
  • Wire brush
  • Grinder with cutting/grinding/wire wheels
  • Clamps
  • Magnets
  • Tape measure / metal ruler
  • Fume extractor
  • and of course, the welder!

Step 3: Clean your metal

Although FCAW is known for being a process that can get away with welding dirty metal, it is still important to clean the area of the metal you plan on welding. This is generally done with some sort of wire brush, grinder, or even better, a grinder with a wire wheel. Removing contaminates such as rust or paint will drastically increase the quality of your welds, so taking the time to clean up your project before you start welding is always a good idea.

Prior to taking the grinder to your work-piece, you should always take steps to make sure the metal you plan on grinding is secure. This is generally done with clamps, but preferably not spring clamps as they don’t always exert the necessary force required to keep the metal in place while grinding on it. Weldors often prefer either a table vice or a C-clamp, as these tools allow the weldor to control the amount of pressure being applied to the work-piece.

Once the metal is secure, you are free to grind away until you have removed the majority of the substance getting in the way of the bare metal. While grinding, be sure to direct any sparks in a safe direction (i.e. not towards a person or a flammable object).

A weldor cleaning a sheet before welding
A weldor cleaning a sheet before welding

Step 4: Cut your metal

In addition to welding metal that has been sufficiently cleaned, you should also make sure your metal has been cut to the appropriate length. Correctly cutting your metal can be equally if not more difficult than the actual welding, depending on what you are working with.

An accurate cut starts with an accurate scribe, or mark, on the work-piece. This is generally done with a soap stone or felt-tipped pen and a ruler with a straight edge. Once you are satisfied with your markings, you can start cutting your work-piece When cutting extended lengths of sheet metal, it is a good idea to use some sort of guide to ensure a straight cut, like an angle or a long piece of square bar stock. For each cut, you should clamp the work-piece down so that it doesn’t go anywhere once you begin cutting.

Cutting a sheet of metal
Cutting a sheet of metal

Step 5: Set up your work-piece

Once you have cleaned your metal and cut it to the appropriate dimensions, it is time to get your work-piece set up so that you can easily tack-weld it together without having to fight with it too much. For mass production work, this is where you would typically devise some sort of jig that would allow you to easily set your pieces into place without having to think about it.

Making sure that the pieces you intend to weld are secured in the exact position you plan on welding them is extremely important. Welding loose materials can lead to countless mistakes and can add unwanted extra work to your project, so make sure to double and triple check your work-piece before you lay down your first tack weld. After you’ve lined everything up accurately, it is time to start welding!

Step 6: Turn on the welder and adjust the settings

Of course, adjusting the welder to the appropriate settings is another essential part of your project. If your sheet metal is a fairly thin gauge, weld on a lower setting with a lower wire speed. As the metal you are welding increases in thickness, you will want to increase the voltage and wire speed as you see fit. It is always good to do a couple test welds on some scrap metal to make sure your settings are right where they need to be before you actually start on your project.

If you are unsure about what settings you should use for your own project, refer to your user manual.

Step 7: Tack-weld the work-piece

After you’ve got everything lined up correctly and set your welder to the appropriate settings, tack-weld the corners of your work-piece together. When tack welding, it is important to make sure that you are actually fusing both sides of the metal together. When you pull the trigger on the torch, pay attention to where you are depositing the weld metal and that you are hitting the work-piece exactly where one piece comes in contact with another. Welding one side more than the other will lead to a lack of fusion which can result in the two pieces of metal not joining together properly. Remember to clean up the area you just welded with the wire brush to remove any slag generated from the tack weld.

Ideally, once you have tacked each corner together, your work-piece will have taken shape and you will be able to see if the sides are aligned and welded into the right position. If not, now is the time to fix your mistakes, as they will be much harder to correct after you finish welding!

A small box with its corners tack welded together
A small box with its corners tack welded together

Step 8: Fill in the remaining areas with ‘bead’ welds

Assuming that you tacked everything together correctly, you can now go back and fill in the remaining seams with bead welds. This is where you will really get to hone in your welding skills, so pay close attention to how your torch angle, travel speed, and electrical stickout affect the appearance of your welds.

The most important thing to consider while performing these welds is maintaining consistency in the above categories. In other words, once you’ve figured out the proper torch angle, don’t change it mid-weld. Your travel speed should be fairly fast, and you don’t want to speed up or slow down mid weld, but maintain a constant pace. Lastly, your electrical stickout should never be more than 1/2” or less than 1/4”, so keeping it at around 3/8” will be your best bet.

Mastering the consistency of your welding technique is the key to being able to weld proficiently, and it’s going to take some practice before your welds come out looking perfect. Keep this in mind if they don’t look great on your first try, just be patient remind yourself that practice makes perfect.

Bead welding the tacked welded sheets together
Bead welding the tacked welded sheets together

Step 9: Clean up your piece

After you’ve welded everything together, there is going to be a bunch of spatter and slag left over from the flux. Now is the time to use the chipping hammer and wire brush to remove as much of this as possible before you start grinding.

Once you’ve removed as much as you can by hand, grab your pair of locking pliers and clamp it to one of the outside edges of the work-piece. Carefully use the bench grinder to grind down your welds until you’ve basically removed the outer layers of your weld and the corners are flush with the sides. While grinding, make sure you keep the work-piece safely rested on the guard. You will probably have to re-clamp your locking pliers once or twice in order to effectively grind each corner. If you welded the edges correctly, each corner should look like a seamless transition on each side and should be free of any holes or cracks. If not, you may need to go back and re-weld the areas with defects and repeat the cleaning/grinding process until you reach the desired results.

At this point you are basically done with your weld!

Step 10: Clean up the area

Clean up the area you were working at and put all the tools back where you found them. This will make your next welding session all the more efficient.

Step 11: Profit!

Once you’re comfortable welding, try to get creative and make something awesome for the home or garden. The more you practice and the more projects you complete, the more you’ll wonder why you didn’t learn to weld sooner!

Source: Instructables


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