A beginner's guide to welding on the farm
Published 09/09/2015 | 02:30
Welding is an invaluable skill to have. Whether it's fixing a small break in a machine or bringing a labour-saving device to life, there's great satisfaction in being able to "do it yourself".
While the welding of some parts and materials require more sophisticated equipment and higher levels of skill than others, a lot of jobs can be done around the farm with even a fairly basic skill level and beginner's welding equipment.
Before you can begin welding you will need some basic equipment, much of which will probably be lying around the average farm workshop anyway.
A file, a wire brush and an angle grinder are all very useful tools for edge preparation. Once these three are assembled you will have to get your hands on a welder.
An arc welder is a cheap and cheerful option, typically costing from €200-€300. Arc welders are well suited to the beginner because they are cheap to both buy and run. Most are powered from a 16 amp, 220 Volt source, but some can even be run from a standard 13 amp 220 Volt source (three pin plug). Arc welding is the most common type of welding undertaken by novices.
A few safety considerations must be taken into account before you begin. Check that the leads of the welder are in good condition and that the electrode holder is undamaged.
Ensure that the dark glass of the welding helmet is intact and not cracked. If you have an automatic welding helmet (one that darkens itself when you start welding), check batteries are in good condition or if it is solar powered, that it is fully charged.
A pair of heavy leather gloves are also very useful to prevent burns caused by sparks during welding, or if you accidentally pick up or touch a hot piece of metal.
To get started, some steel plates are very good for practicing on. Clean the plates with a wire brush or an angle grinder, ensuring their surfaces are free from rust, dirt and grease.
This is a simple but very important stage in the welding process. It is almost impossible, especially for the novice, to get a clean, well formed weld on a dirty or rusty piece of metal. A 2.5mm or 3.2mm mild steel rod will do fine to get started. These can be purchased at any hardware or creamery and cost from as little as €10.
Attach the earth lead to the work piece and practice striking and maintaining the arc. This is the step that those starting out find to be the most difficult. The arc is struck in a similar way to how a match is lit; the end of the electrode (the rod) is scraped along the work a short distance and then rapidly lifted about 1.5mm. The end of the electrode must be kept roughly this distance from the work piece at all times to ensure a strong arc is maintained.
Novices shouldn't be afraid to experiment with the current by changing the current setting on the welder and trying again. The current setting depends on the thickness of the metal being welded and the size of the electrode being used.
The thicker the work piece, the higher the current you will need, and hence the thicker the electrode. If you find that the weld is lumpy and not penetrating the work piece and it is hard to maintain the arc then the current is probably too low.
However, if you find that the welder is burning through the steel too much, and if there are lots of spatters of weld at each side of the main weld bead, then the current is probably too high.
Practice is the only way of determining the correct current for the job, and it will come with experience.
Next Week: How to tell a good weld from a bad one