Selecting the right welding gas for your MIG and TIG application can make or break your project.
The reason for this is simple – different metals have different properties.
Metals therefore react differently to the elements in the oxygen in the air once they begin to melt during a welding process.
A welding gas, or shielding gas, is designed to protect your metal from contamination once it begins melting and thus protect the integrity of your weld.
Without the appropriate welding gas your metal can contaminate and your welding join can become frail overtime.
So, with that in mind, lets talk about welding gas or shielding gas.
The appropriate welding gas for welding a particular metal will differ depending on whether you’re MIG or TIG welding.
The thickness of the metal must also be taken into account.
Before we talk about the different welding gas combinations that are appropriate for different metals, it is worth getting to know some basic information about the different gases themselves.
The most commonly used welding gas for MIG and TIG applications. Can be used pure or mixed with other gases. Argon is colourless, odorless and non-toxic gas. It composes 93% of the earths atmosphere but it can create an oxygen and nitrogen free inert shield, making it appropriate for welding a wide range of metals and alloys. It is frequently mixed with Hydrogen (H2), Carbon Dioxide (CO2), Helium (He) and Oxygen (O2) to optimise the quality of a weld depending on the thickness and characteristics of the metal.
Helium is an extremely light and non-flammable gas. In fact it is the second lightest gas behind hydrogen. It is odorless, non-toxic and tasteless. Its primary function as a welding gas is to provide an inert shield and prevent contamination through oxidisation for a wide range of metals. These include stainless steel, aluminum, copper and magnesium alloys.
CARBON DIOXIDE (CO2)
Carbon Dioxide is an odorless, tasteless, and nonflammable gas which is found in the earth’s atmosphere. As a welding gas it is commonly combined with argon (Ar) as an inert shield for low alloy steels, mild steels and carbon steels.
Once again it is non-toxic, odorless, colorless and tasteless. It is the lightest of welding gases. As a welding gas, hydrogen is commonly combined with Argon for high temperature metals, especially stainless steel. It is commonly used in plasma cutting processes.
Occasionally used as a welding gas, usually in combination with argon for use on duplex stainless steels. Nitrogen is again colorless, odorless, and non-toxic. It is non-flammable at normal atmospheric temperatures. Propane
OK, Now that you now the basic about the main gases used in welding, lets talk about which ones and which combinations, are appropriate for the metal you want to weld. Let’s start with MIG welding
MIG welding of Mild Steel
If you’re looking for an all-purpose Mild Steel welding gas an Argon-Co2 combination is your best option. Argon-CO2 blends produce minimal spatter, a nice bead appearance is forgiving on thinner mild steels meaning it is less likely to burn through. eWelders sells an 86% Argon-14% Mild Steel welding gas from Ross Welders which we recommend as an all purpose mild steel gas. We sell these in 12 x 1120g cylinder bulk packs at an extremely competitive price and include free shipping to save you money. Click here to view this product. As an alternative you can use a pure Co2 mix. This will provide a deeper weld penetration but will result in a rougher weld than if you use a Argon-Co2 mix. It is therefore worth keeping in mind depending on the project. eWelders sell a pure Co2 welding gas bulk pack here.
If you’re looking for an optimum welding gas combination depending the thickness of the mild steel, different Argon-Co2 combinations are available from specialist gas dealers.
Here is our is recommendation:
0-4mm Mild Steel: 93% Argon, 5% Co2, 2 % Oygen (O2)
4-12mm Mild Steel: 84-86% Argon, 14-16% Co2 (Click here)
12mm+ Mild Steel: 78%Argon, 20% Co2, 2% O2
MIG welding of Aluminium
Argon is generally the go to gas for aluminium welding, whether you’re TIG welding, or MIG welding. We recommend you use a pure argon shield when welding aluminium base metals less the 15mm thick. eWelders provide free shipping on 12x1120g cylinders bulk packs of pure argon for $379. This represents super value for welders who regularly weld aluminium.
For welding thicker metals a helium mix can be added to increase the penetration. Start at about 20-25% helium for 15mm thick and then increase the helium content as the aluminium gets thicker. Helium mixes will increase the price of the welding gas shield, in comparison to argon.
DO NOT use a welding gas containing any Carbon Dioxide or Oxygen when welding aluminium, regardless of whether you’re using MIG or TIG process at it will contaminate the metal and affect the weld quality.
MIG welding of Stainless Steel
Stainless steel does have different properties to mild steel.
These need to be taken into account when selecting your welding gas shield. However, it is far less fickle than aluminium and the welder has various shielding gas options.
An Argon-Co2 blend will provide good results on common stainless steels.
But stainless does contain a higher level of chromium which increases its resistance to corrosion. This contributes to a slightly higher melting point than mild, carbon-based steels.
For this reason many welders opt to use a helium combination as helium conducts more heat and increases the weld penetration. Helium will increase weld speed but won’t necessarily translate to cost saving because it is more expensive than Argon and creates higher consumption rates.
For high quality welds consider an argon-helium-Co2 blend with about 25-33% helium and 1 Co2. This will create a high travel speed, better control of distortion in thin material, and superior bead shape.
Mig welding of stainless steel to Mild Steel
Consider a Argon-Co2-helium blend contain 25-33% helium and 1% Co2.
Pure argon is generally the welding gas of choice for use as a shield when using the TIG process. TIG welding is generally suited to welding stainless steels and aluminium. When welding aluminium, a pure argon gas such as this one can be effectively used for metals up 18mm thick.
Once the aluminium base metal exceeds this width it is worth adding a helium blend to increase weld penetration. We recommend a 75% Argon 25% helium blend for aluminium welds thicker than 18mm.
A similar principal applied when choosing a welding gas shield for TIG welding of stainless steel. Pure argon can effectively be used for a width of up to 8mm. Once the stainless steel exceeds this width add switch to an argon-helium blend.
What welding processes do I need my welder to perform?
This is probably the most commonly asked question among beginner welders, and it is often the subject of confusion. But don’t be daunted when trying to to decide whether you need, TIG function, MIG function, MMA function or all three.
Welding is a complex skill but the following information will give you a basic overview in the main welding processes. Keep this information in mind when making your choice but If you require more detailed advice after reading this information, don’t hesitate to give us a call and we can assist further with advice in choosing your welder. It is important to note, that no one welding process is perfect for all welding applications, so if you’re looking to perform a versatile range of applications, you may wish to purchase a multi-purpose welder, capable of performing MIG, TIG and MMA function.Click here to view our multi-purpose range.
Here is a basic guide to the three main welding process (MIG, TIG and MMA):
MMA (Stick/Arc) Welding
MMA welders use an electric current flowing from a gap between the metal and the welding stick, also known as an arc-welding electrode. This form of welding is great for welding most alloys or joints. It can be used indoors and outdoors and is a good choice if you plan to weld in potentially windy conditions. It is effective on rusty and dirty metals.
A key to Stick welding is learning to strike and maintain an arc. This can be a challenge but once mastered it is a very effective form of welding on many metals. It is generally suitable for welding metals no thinner than 1.02mm (18-gauge). Welds should be cleaned upon completion. It is an economical form of welding and is is great for welding thicker metals of 6mm or more. They are a good choice for farmers, hobbyists and home maintenance chores.
Key MMA welding points
- Great for windy conditions
- Effective on thicker metals
- Effective for welding dirty or rusty metals
-Good for general DIY jobs, home maintenance and farmers
Click here to view our range of MMA (Arc) welders
TIG welding is an arc welding process. It uses a non-consumable Tungsten Electrode to produce the weld. This weld area is protected from contamination by a shielding gas, along with a filler metal. TIG is an extremely precise form of welding and gives the welders great control and stronger welds than other processes.
It is most commonly used to weld thin sections metals, including alloy steel, and stainless steel, because of the precision it gives the welder. It is also an ideal process for non-ferrous metals such as aluminum, magnesium, and copper alloys. It is a more complex form of welding and will require more time to master. But once you’ve got the hang of TIG welding it is a brilliant process.
Key TIG welding points
- Extremely precise, and produces strong welds
- Precise results on thin metals.
- Ideal for allow steel, stainless steel, aluminum, magnesium, copper alloys.
Click here to view our TIG inverter welders
MIG welders use a wire welding electrode on a spool. The spool is fed automatically at a constant pre-selected speed. The arc, created by an electrical current between the base metal and the wire, melts the wire and joins it together with your base metal.
MIG welding is clean, and it is great for thin and thicker metals. It is easy to master as long as you don’t rush in without doing your research. MIG welding is effective on a wide range of metals including steel, aluminum and stainless steel. It is effective on metals as thin as 0.4mm
Key MIG welding points
- Easy process to master Very clean welds
- Effective on a wide range of metals including steel, aluminum and stainless steel
- Great process for welding thin metals with precision
Click here to view our compact MIG welders
Metal chart. This chart provides you with a useful guide of which process are suited to which metals.
|Exotic (Magnes, Titanium)|
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By Kym Morgan
21 May, 2014
MANY a welding successful workshop has been established in the Aussie backyard shed.
After all, the shed is often a man’s own private space and it can provide the ideal atmosphere for a day’s welding.
But there are a few dos and don’t when it comes to setting up your shed as a welding workspace so bare these things in mind before you start your project.
If you are in the market for a shed in which to set up your welding workshop, we recommend these guys - cheapsheds.com.au. Cheapsheds is Australia’s biggest selling online shed retailer and they have a massive range and offer first-rate customer service.
Good luck and happy welding
29 Apr 2014
ALUMINIUM WELDING is to the welding industry what Luis Suarez is to the Liverpool Football Club.
It can be difficult to work with but it’s extremely important.
Aluminium is one of the most widely used metals in the modern world and any serious welder is probably going to need to master it at some point.
Don’t agree? Have a think about aluminium’s role in automotives and construction and for a start.
In automotives, aluminium is used in car, truck and bus engines block, transmission housing and body panels. In construction, it’s used in sheet products for roofing and wall cladding and in castings for builders.
Then there’s aluminium’s role in packaging, and the electrical sector. You get my drift!
So, rather than avoid aluminium welding it’s time to embrace it, master it and massively increase your welding skill set in the process.
This Blog is dedicated to the art of TIG Aluminium welding, which I believe is the best process for working with aluminium but in a subsequent blog I’ll cover off on MIG aluminium welding. I recommend steering clear of Stick aluminium welding. Getting precise enough welds for aluminium using the Stick/Arc process is a massive ask and I don’t recommend it.
Ok, so TIG aluminium welding. let’s get into it.
Prepare for your project
As with every welding process, preparation is key. Remember the old saying, if you’re given hours to chop down a tree, spend the first seven hours sharpening your axe.
Make sure you’ve got the tools you need
Given we’re talk about TIG aluminium welding this an obvious one. More specifically, you should consider investing in a TIG inverter welder with AC (alternating current) function if you’re seeking to achieve high quality aluminium welds. The reason AC welders are more effective on aluminium, and magnesium, is because of the properties of these metals.
Aluminium forms an oxide layer when exposed to air and this layer has a far higher melting temperature than the base metal itself – 1982C, compared to 648C.
If not removed properly, this oxide layer will inhibit proper weld fusion and affect its quality.
A TIG welder with an alternating current basically erases this oxide layer from the surface, so that the integrity of the weld is not compromised when the base metal melts. eWelders.com.au sells a big range of TIG welders with AC/DC function starting at $1199. A big investment, but extremely cheap compared to our competitors.
Way out of your price range? Don’t despair. It is possible to aluminium weld with a TIG inverter that only has DC function which start fromjust $249 in price here. The key will be cleaning away the oxide layer manually before you start your weld. We will cover off on this a little lower in this article.
The aluminium Filler Rod will bond your two pieces of aluminium together, as we will explain later. These can be purchased inexpensively at eWelders here.
You will use this as your shielding gas. Pure argon is an economic alternative. For added stability you can use argon with 3% helium.
Obviously you’ll need to protect yourself when carrying out aluminium welding. Click here for our article on welding safety and preparation but in the meantime make sure you cover off these basics.
Prepare the aluminium
Ok, now that you’ve got the equipment you need its time to get ready to weld.
First of all, you should clean your aluminium. As I mentioned earlier, if you are using a TIG inverter which only has DC function, it is crucial that you do this in order to remove the oxide layer that will have formed on your aluminium. This layer has a far higher melting temperature than the base metal and, if not removed, will compromise your weld. To clean your aluminium sheet:
Prepare your filler rod
To complete your cleaning preparation your should clean the filler rod you intend to use. a dirty filler rod can contaminate the weld so use an abrasive cleaning pad to clean the rod before you start.
Before you start have a few practice runs. There’s no need to light the torch for this if you’re trying to save on metal.
The filler rod
A few final bits of preparation!
Preheat the aluminium
Aluminium is much more cooperative if it has been preheated to about 175C. Failure to do this can lead to a weak, shallow weld. To preheat your aluminium weld you can set your oven to 175C and put it in there. Don’t worry about the sheet melting while it’s in the oven. Remember, aluminium has a melting temperature of 648C.
Alternatively, use a gas torch to heat the heat sink that the aluminium sheet is clamped to. This will distribute the heat throughout the aluminium.
Fit your aluminium sheets together as tightly as possible
TIG welders don’t like it when the metals are not fitted together nice and tightly prior to welding. It can result in a weak weld. Fill your sheets before you clamp them to avoid this.
Set your welder to the appropriate settings
Congratulations, you’re done!
Don’t be disheartened if you’re first attempts at TIG aluminium welding is a raging success. You’re taking on a more advanced leve welding skill here and it will take a few attempts to master.
By Kym Morgan
17 April 2014
SO, you’ve taken on a welding project? First of all, congratulations on making a brilliant decision.
Having the ability to weld not only introduces you to a highly satisfying, incredibly addictive, hobby it also opens up a whole new weld, i mean world, of possibilities.
Sorry, no more cringe worthy puns, i promise!
Look around you, chances are something within your immediate vicinity contains a weld. You’re car is full of spot welds. Look at the the hand railing nearby, the table across the hall, the metal shelving out in the garage…You get my point.
Welding is a key part of the manufacture of so many products which play an important part in our everyday lives. Welding also plays a part in all of the super-structures around us (like buildings and bridges) and the auto-motives we use every day.
By becoming proficient in welding and taking on your first project you are about to enter an art-form which will not only give you satisfaction and enjoyment, but help you to carry out DIY and renovation jobs, make new products, and save money.
With any welding product, a few golden rules apply and I wanted to share one of them with you today.
This rule applies whether you are undertaking a MIG, TIG or MMA welding process. It applies whether you’re carrying out a basic repair around the home or carrying our a major car restoration project.
Plan your welding job meticulously and ensure you have all the equipment you need to do the job right, and to do it safely.
Purchasing equipment for that first welding job can seem like a major expense. But remember, many of the purchases are one-offs, so these are investments in future welding projects, Ultimately by undertaking welding projects yourself you can save money, not to mention get a massive amount of enjoyment and satisfaction.
So, before you start your project, make a list of all of the equipment you will need to do the job right, and to do it safely.
The welding machine
Obviously the starting point is to buy the right welder for your project. If you haven’t already done this, you’ve come to the right website. At eWelders.com.au we have a massive range of more than 100 quality welding machines which you can view here. If you need technical support on this important decision, you can contact us.
I’m not going to go into too many specifics about which welder to chose in this blog, as this is another topic in itself. But, for those still to chose a welder, your starting point will be to ask yourself these three basic questions:
Once you know the answer to these three basic questions, you’re well on your way to buying the right welder. Don’t be overwhelmed by the highly-technical nature of welding, and the amount of choice that is out there on the market. Start by asking yourself the above questions and doing a little research. eWelders frequently asked questions section has a handy guide to which welding process are suited to which metals. Click here to view this. For a beginner, it will definitely be worth purchasing a kit with your welder. These kits will come with things like welding guns, leads, torches and regulators, to save you having to buy them separately. Contact us if you need some technical support and always buy your welder through a reputable dealer such as eWedlers.com.au.
What comes next?
Once you have your welder and you’ve worked out your welding process, it is time to make a list of all the materials and consumables you are going to need to do the job right. This will obviously vary greatly from job to job. But you will need to check off the following points.
Whether you’re using MIG wire, TIG filler rods, or MMA electrodes, ensure you think about the amount of consumable material you will use during your project and stock up accordingly. Also ensure you get the the right consumable for your project. Different MIG Wires are suited to welding different metals, for example. The good news is, all of eWelders’ consumables are clearly labelled and explained on our site, making it easy for you to select the right consumable. Click here to view our consumables.
Safety should be the upmost priority for any welder. Welders expose themselves to electric currents, potentially harmful gases, extreme heats, and debris. Therefore you need to protect yourself before you start your project.
It is imperative that you use a specialised set of welding gloves whenever you weld. As you will see when you visit eWelders’ gloves page here, they are not expensive but they do play a crucial role in the protection your hands, because welding gloves are made from leather and are flame resistant. Do not use ordinary gardening gloves, or cheap cotton gloves when you weld.
You are going to need to protect your eyes, and your whole face when you weld. Without a hemet you risk damaging your eyes due to exposure to the extremely bright ultraviolet light which occur during a weld. You also risk burns to your face from sparks that fly up off the metal as you weld. Again, a welding helmet can be purchased inexpensively at eWelderscom.au’s helmet’s page. For beginner welders, we recommend you buy an auto-darkening helmet. auto-darkening helmets automatically adjust the lens to darken and protect your eyes when you strike an arc. THe helmets adjust far quicker than you can blink your eyes. This not only protect you it give you the advantage of being able to see what you’re doing prior to striking your arc. eWelders only sells auto-darkening helmets.
Like your gloves, it is important to invest in a specialist welding jacket because welding jacket’s, unlike many general jackets, are non-flamable. Once again, eWelders.com.au has a good range of well-priced jackets for you to browse here.
Now that you have your safety equipment, and your welder, start to forward plan.
There is a good chance you will need something to cut your metals with during your welding project. eWelders stocks a comprehensive range of plasma and gas cutting machines which can be viewed here. If you do not wish to purchase a plasma cutter at this point, you could consider purchasing a metal cutting saw, although be prepared for sharp edges around your cuts, meaning you are also likely to need an angle grinder.
If you’re working with sheet metal it may also be a good idea to have a pair of metal snips handy, and a sheet metal brake, to help you snip and shape your metals.
Once you have all of your safety equipment, your welding and cutting equipment, and your consumables sorted, it’s time to buy your metals. You can visit any hardware or sheet metal store to purchase your metals but do your homework. Work out how much of each material you need, allowing for off-cuts.
For beginners, it will be worth buying some practice cuts.
There are a whole host of other equipment you may need to consider before you start your project, which is why it is important to have a plan.
At your home workshop, for example, you may needs a work bench, and a trolley. You are also likely to need tools like clamps, and chipping hammers, and you may need to purchase cables, leads and adapters. eWelders is a comprehensive welding supplier and stocks all of this equipment.
Remember, by purchasing all of the equipment you need before you start your project, you are setting yourself up for success. You are also less likely to have to down tools when you realise you are missing something you require. THat is a massive momentum killer! Most importantly, you’re setting yourself up to weld safely, and to enjoy your project.
Good luck, and keep reading our blog for more useful welding tips.