Eight tips for creating a good weld

Mathew Hefferan of WIA Image: WIA

It’s important to know the basic principles to create a safe, strong and clean weld. Mathew Hefferan, field applications specialist at Welding Industries of Australia (WIA), shares his top eight tips to creating a good weld.

1. Safety

The first thing to consider before starting is to ensure the correct safety equipment. This includes gloves, a fire-resistant jacket and a helmet.

Even an occasional welder can make the most of the latest technology in welding safety with WIA’s BlueFX and ViewFX helmets.

Designed for the welder who wants protection, performance and comfort at an affordable price, these helmets feature auto-darkening technology making it even easier to remain safe, especially for people new to welding.

2. Select the right machine for your weld

Considering the variety of welding processes available, selecting the right welding machine for your workshop could be a confusing and difficult decision. Matching the best process to the application can be the difference between profit and loss.

There is no single welding process suitable for all welding situations. For this reason, it is necessary to weigh the advantages and disadvantages of each welding process.

The most common welding processes used for fabricating metals are gas metal arc welding (MIG), flux-cored welding, gas tungsten arc welding (TIG) and shielded metal arc welding (stick electrode). To make an evaluation of the welding process most appropriate for the job at hand, the following factors should be considered:

  • type of material being welded
  • thickness of the material
  • welding position
  • type of welding power source and the amount of current available
  • time requirement

Machines have come a long way too, allowing for compact multi-process machines (MIG, flux-cored, stick and TIG).

3. Select a process

MIG, flux-cored, stick and TIG? Don’t get confused by all the different terms.

Wire welding uses spools of wire fed through a gun, and the constant feed minimises starts and stops. This makes it easy for relatively inexperienced welders to create good looking joints. It’s also faster, more economical and better suited to welding thin sheet metal.

There are several types of wire welding, including:

a. MIG (metal inert gas): MIG welding relies on a constant stream of shielding gas to protect the weld from contamination. The gas is plumbed into the welding gun from a gas bottle. The limitations to MIG welding are that it can be difficult to use outdoors (wind can blow away your shielding gas), and you have to cart around the gas bottle.

b. Flux-cored: Flux-cored welding uses wire that is specifically designed for use with or without shielding gas depending upon the wire being used. Those designed for use without gas (self-shielded) are often recommended for outdoor work

c. Stick: Stick welding is frequently the best choice for quick repairs and is often the first process that most beginners learn. It’s easy to set up and as the name suggests, it uses a stick electrode like Austarc 16TC and 12P, so you don’t need a wire feeder. Stick is slower than MIG welding, but often more forgiving when working with dirty or rusty metal. Stick is not recommended for thin sheet metal welding.

d. Tungsten Inert Gas (TIG): TIG welding is preferred for architectural work or automotive work where the weld has to look good. It’s also a good way to weld thin metal and sheet metal and achieve a seamless look. On the difficulty scale, TIG is usually considered the hardest to learn, but it’s not out of grasp if one puts in the effort. TIG machines can weld a variety of metals, but if you’re looking to specifically TIG weld aluminium then a machine with AC/DC capabilities is required (for example the WIA Weldarc 200i AC/DC machine).

Different processes suit different materials and if you are intending to weld a variety of materials it is worth investing in a multi-process machine such as the WIA Weldmatic 200i and Weldmatic 250i.

4. Ensure your material is clean

Another important step in the process is to make sure that all the materials are clean. Any oil, rust, paint or mill scale can cause contamination and will result in a poor weld. Before you start the welding process, brush all your equipment, surfaces and materials down to ensure everything is clean.

5. Select the correct settings

Having the correct settings on your welding machine will place a huge impact on the quality of your weld. Every WIA product comes with a product data sheet that will enable you to determine the optimum settings for your weld.

6. Maintain the correct stick out

When MIG welding, it’s important to maintain the correct contact tip-to-work distance (CTWD). If the CTWD is too close, it will cause excessive tip wear, and if the CTWD is too far, it will result in a reduction in amperage; both issues will result in a poor weld.

The optimum CTWD for a 0.9mm wire is 10 to 16mm and for a 1.2mm wire is 16 to 19mm.

7. Adjust your machine for every weld

Check your reference chart and adjust voltage and wire feed to suit. Make several practice welds on some scrap metal to ensure comfort with the settings.

8. Practice, practice, practice!

Finally, as with any skill, practice makes perfect. The more welding you do, the better you will become.