Welcome to our first welding tips for machines article, in it we will go through the basic selling points & features found on welding machines, the kind of applications and metals they are good for and certain pitfalls you might want to stay away from. Armed with these welding tips as a novice welder you would be able to make a smarter purchase in your first welding machine.
Welding much like anything else is a skill and takes years to perfect. However, it can be quite quick and easy to learn as long as you take some time to understand the physics about welding in general. Because of the fairly recent widespread use of inverter technology in welding, striking the weld (which is usually the trickiest part of learning welding) becomes much less frustrating thanks to the easy arc.
Safety equipment such as auto-darkening helmets makes the process much faster, safer and less frustrating than years ago when they weren’t around. We will be going over the most important welding tips & facts 90% of beginners don’t know. From Arc welders to flux cored welding. The below guide is only a basic beginners article and has been formed out of the most common questions we get in the store about welding in general. We will be focusing on welding machine information primarily, and in the future feature, some how-to information about the actual actions of welding itself.
Nearly every technological advancement in the field of welding has made it safer than before. Inverter welders are more energy efficient and greatly reduces the risk of fire or electrocution. Auto-darkening helmets practically removed the danger of Arc Eyes (flash burns to the eyes) and other injuries to the facial area. Its just very important to understand the elements & physics of welding in general, as long as you respect these you can avoid injury long term. Just always use gloves, helmets and avoid using long thin extension cords. Important welding tip, avoid standard welding helmets, Auto-darkening helmets are really cost effective and they work. If you ever get Arc Eyes you will regret it.
- helmet (avoid normal helmets if you can, get auto darkening), make sure you get ones that cover at least a large portion of the head. Most good helmets do.
- Gloves, overall & skin cover. The heat radiation from welding will give you a very unpleasant skin tan.
- Additional hat or banana to protect facial hair and your upper head
- welding apron to protect the legs area
- safety shoes or at least leather shoes to prevent conductivity in the rare case of a short circuit.
You will see these machines everywhere and with good reason too. They work. The main difference between these machines and the technology before them (oil cooled welders) is the output being DC current. AC current (alternating current) is fed into the machine, the inverter transformer changes that into a DC voltage (low voltage high amperage) and the result is a much lighter, energy efficient machine. The DC current also tends to cause less sticking and less spatter than the big copper transformer machines from years before. Inverter welders also have a very good duty cycle for their size and cost. When you move over to more industrial machines heavy copper transformers are still popular.
- due to the digital nature of the electronics running the transformer more precise and accurate current output can be chosen.
- typically air cooled (also cools down much faster than older oil cooled machines)
One of the main selling points discussed on welders is the duty cycle. Duty cycle is mainly the explanation of how long a welder can weld at a certain current output. Most welders will display a duty cycle percentage along with a current output for example 60% @ 200A. The percentage is derived from how long the welder can output that current in a 10-minute window without overheating (under a certain room temperature).
So this welder will weld at 200A for 6 minutes before its transformer becomes too hot and shuts down. The welder must then rest 4 minutes in a 10-minute window in order to be used again. This means 6 minutes on 4 minutes of, exceed this and the welder might overheat or cut itself out. However when the output current is reduced the duty cycle greatly improves. A welding tip we recommend to customers is to pick a machine about 25% above what you will use and you will never reach the duty cycle under normal conditions.
Please bear in mind there are many variables at play here so manufacturers do tend to be ambitious with their specifications. So we advise our customers to go for 25% above the current they need to get a well-performing machine for the cost. In a South African climate welding in the 40C sun, the 60% duty cycle becomes unrealistic on any machine.
ARC Welding (MMA Welders)
Also called shielded metal arc welding. The staple every workshop should have, it all begins with the old trusty arc welder. Welding is done by creating a fusion between a shielded metal rod and the metal being welded. Arc welding rods are covered with a type of flux that when the weld & heat is created the flux burns creating a shielding gas around the weld protecting the weld from its enemies oxygen, moisture and other gasses present in the air around you.
MMA (manual metal arc welding ) welders are currently the cheapest and most reliable machines due to the fact that they are very widely used and have no moving parts. Its usually on an MMA welder that most welders learn the skill. MMA is still the most popular welding solution and more widely used on ferrous metals. The only problem they have are the fact that the welder needs to stop welding every few seconds to change the rod, and ARC welders are not very good for precision work and non-ferrous metals due to their deep penetration, and splatter around the weld.
- cost-effective, super compact machines
- can be utilized as a TIG welder on ferrous metals (explained below)
- no gas required
- very easy to learn (great for beginners)
- not considered great for fabrication or manufacturing (rods are quite short and need to be replaced every few seconds)
- fewer consumables, only rods are needed.
A few welding tips on welding rods
Quality of the weld depends greatly on the rod used. Aspects to consider is quality, thickness, metal, type of current, the direction of the weld. All these aspects are explained on the cover of the packaging of the product.
However, some brands do not suggest amperage used for each thickness of rod so some prior research must be done in order to get the right welder & rods. Feel free to use this calculator from Millers to identify the right thickness of rod: ARC welding rod calculator. The thickness of rod depends on what kind of thickness you are planning on welding on. The thicker the rod the deeper the rod will penetrate to look at your steel being welded and take it from there.
The nice welding tip about choosing the right rod is you can achieve a very good duty cycle on the welder if you use a lower setting on the welder. You can buy a small 160A machine and still weld for hours at a time if you use a 1.5 mm rod at a lower amperage than the maximum of the machine. In other words, you can save money long term by getting a larger machine and lowering the risk of the machine picking up problems over time. Just remember to keep these rods absolutely dry at all times.
MIG Welders (Metal Inert Gas Welding)
MIG welders are different to ARC welders in the biggest sense because they use a fed wire instead of rods. The wire (steel) is fed from the roller or feeder through a torch and then protruded from a tip. Because most wires are just metal, the weld must still be protected to an inert gas is also fed throughout the torch to shield the weld from oxygen and moisture. The reason for MIG welders widespread use is the added benefits of being able to weld continually for longer compared to rods or TIG welding. The welder can weld as long as the roll still is being fed and the duty cycle holds out. This makes it very popular in the fabrication business where longer welds are necessary for example sealing pipes or water tanks.
The resulting weld is also cleaner and created with less spatter than ARC welding. Problems with MIG welding include having to deal with gas bottles or the more expensive flux core wires explained below. They also require more training and additional settings to start with (wire feed speed for example). They are more costly machines because of the additional wire feeder system and more complicated torch mechanisms.
some things to look out for when getting a MIG machine
- pay attention to wire thickness and the feeder size compatibility
- decide if you need to use GAS or NO GAS. If you need to use flux core get a machine with revers-able polarity.
- consumables include. Tips (various sizes), Gas shrouds (with skilled welders these last a long time), gas and the wire.
Types of Welding Gas for MIG or TIG Welding
This point will be on MIG welding & TIG welding. To answer this question yourself easily you simply need to understand what happens when you weld (fusion). When welding metals are melting creating large amounts of heat, during this process heat attract moisture & oxygen from the immediate environment and this will cause the weld to become very brittle. So Gas (in most cases CO2 or ARGON gas) are used to create a temporary shield around the heated area to keep it safe from the enemy or welding water. Benefits of using gas are the weld is practically clean with no slag to clean up.
The only decision left is done I use CO2 or ARGON gas. CO2 gas is the more common and cheaper to use. In today’s industry, you are more likely to come across CO2 & ARGON mixtures, the reason for this is a mixture creates less splatter than pure CO2. CO2 gas is typically used for ferrous metals these are metals containing iron. Pure Argon gas, however, has much less penetration than CO2 mixtures and for this reason, it is popular to use on non-ferrous metals such as aluminum, magnesium or copper. In most stores hiring gas bottles, you will find a CO2 Argon mixture and will work 90% of the time. Only when you are working on more complicated metals you will have to switch to pure gasses or different mixtures.
- less dust and spatter compared to flux based welding (MMA and Flux core)
- a better choice for non-ferrous metals compared to Flux core.
- depending on brands used can work out cheaper per meter of weld due to high costs of flux cored wire.
Flux Cored Arc Welding
Similar to how ARC welding rods work this is accomplished by using the flux that is filled inside the welding wire used. You see the weld must still be protected from oxygen & moisture in the environment, so flux is filled inside the wire to shield the heated weld. Benefits of this are less effort and no need to worry about gas bottles. The biggest problem with flux core wire is an additional cost of wire & some slag being left on the cooled weld. Due to the fact that you don’t have to worry about additional gas bottles, this solution is more compact. For welding on thinner alloys in most cases, you will have to switch the polarity on the MIG welder and only some have this feature. The handle of the welder is basically switched from + to -. This changes the direction of the current and changes the penetration of the weld. A good welding tip to know is to not do flux welding on a MIG machine with no such feature. You can find this feature near the drive roll or the front of the machine.
- can be used in windy conditions thank the slag being formed on the weld
- more productive than gas shielded welding up to 100% faster depending on the equipment used
- slag needs to be cleaned up after welds
TIG Welding (Tungsten Inert Gas Welding)
TIG welding while probably being the least common practiced type is by far the most advanced and precise. A very popular choice for non-ferrous metals due to the shallow penetration and better control over the flow and arc of the weld. Instead of using rods or wire the user manually feeds the metal into the weld by hand so the welder has absolute full control over every aspect of the process. The result is a much finer control when working with a sensitive material such as aluminum or magnesium, but the rate of the welding process is much slower. Other problems include the fact that the torch handle warms up over time and can even melt or cause the welder injury if precautions are not taken. Argon gas is usually the go-to choice since non-ferrous metals are welded in most TIG welding cases. TIG welding is not possible without gas at all. The arc is created by the tungsten tip located in the shroud of the welding torch. The shroud is made out of a ceramic material due to the massive amount of heat present for extended amounts of time.
- very precise
- the go-to choice for thin aluminum and other non-ferrous metals
- more professional machines allow the welder control over nearly every aspect of the weld.
- learning is on a curve, takes more time and patience to master.
- speed vs metal welded ratio is low (it’s slow)
- consumables include the tungsten tip, the shroud, gas & metal rods.
- tungsten tips are sharpened according to the material being welded.
TIG Welding with a DC Arc Welder
Interesting welding tip, you can scratch start TIG weld with any DC inverter ARC welder by simply connecting a TIG torch, the gas would just have to be fed from the bottle directly to the torch. When using an arc welder to TIG weld just remember the polarity is still the same so would only work on thinner ferrous metals. Because the torch has no control from the machine the arc is started by manually scratching the surface or the metal. Not quite as precise as using a conventional TIG machine with a trigger, but a really handy trick to add more value to your existing ARC welder.
PS: not all Scratch TIG torches will fit normal DC inverter MMA machines. Make sure the plugs fit. Most torches for sale are intended for screw-in fittings found on TIG machines where the gas goes to the torch. For this, to work, you need a TIG torch with no trigger and a separate tube for the gas and a male lug lock in fitting (called DINSE connector)
Thank you for taking the time to read this basic introduction to welding tips article. We wrote it to help our customers make the right choice in product. There is plenty more to be said about what has been mentioned above but this is aimed to be a very basic introductory article. We will be publishing more in-depth guides about each aspect of welding going forward. If you have any questions about any info here or if we got anything wrong please comment below or interact with us on social media. We really like to interact with customers.