Aluminum is one of the most important metals in welding and construction industries. Its applications and importance cannot be overrated.
In the past, aluminum is often thought to be difficult to weld, but this is not entirely true at present. Aluminum can now be easily welded to make amazing structures.
There are several methods of welding aluminum material which includes MIG, TIG and Stick welding processes.
The choice of the method to employ generally depends on the material thickness.
TIG welding is best for welding thinner stuff, whereas, MIG welding is best employed for welding aluminum up to 1/8 inch or thicker.
From the other end, Stick welding can be used to weld both thick and thin aluminum materials. In this article, you are going to discuss how to weld aluminum using five different welding methods.
How to Weld Aluminum with MIG
Metal Inert Gas welding is one of the most popular welding techniques employed by both welding enthusiasts and professionals as well.
This welding process uses shielding gas and a consumable electrode which is continuously fed via a welding gun.
Welders who are used to welding steel will require to make some certain adjustments while welding aluminum.
This is because aluminum is a much softer metal and a better conductor of heat as compared to steel.
Therefore there is a need for more control over the power supply; the feed wire must be larger and also the feed rate of the electrode must as well be well regulated.
The following paragraphs highlight the process of welding aluminum using MIG welders
Step one:
Choose the right equipment and materials
Get a powerful welding machine for welding thicker metals. A 115V welding machine is strong enough to handle up to 3mm thick aluminum with sufficient preheating; a 230V welder can be used to weld aluminum of about 6mm thick or more. If you are going to be welding aluminum regularly, it’s advised you consider investing in a welding machine with an output power greater than 200A.
Use the appropriate shielding gas
Generally, clean aluminum welding is achieved using pure argon as opposed to steel welding where a mixture of argon and carbon dioxide is used. Aluminum welding does not require new hoses, however, regulators that were specifically designed for carbon dioxide may need to be replaced.
Use Correct electrode
The thickness of the electrodes used plays a vital role while welding aluminum. You will agree with me that thinner wire is very difficult to feed, whereas, thicker wire needs a very high amount of current to melt. A good electrode for welding aluminum should not be less than 1mm in diameter. One of the most preferred electrode selections for welding aluminum is 4043 aluminum. Harder alloys such as 5356 aluminum are easy to feed but need higher current
Step two:
Using the appropriate technique
Aluminum feeding kit should be used to feed the electrodes. Aluminum feeders are available in most stores. These feeders allow you to feed aluminum wire with the following features with much ease and accuracy.
Large holes on the contact tips
Aluminum is generally known to expand more than steel when heated. This means that the tip will also need larger holes than those of steel wire of the same size. Nevertheless, the holes must be small enough to provide effective electrical contact.
U-shaped drive rolls
The drive rolls to be used should be good enough not to shave the aluminum wire. The outlet and the inlet guides of the aluminum feeders should not shave the softer aluminum wire.
Non-metallic liners
Non-metallic liners help greatly to minimize friction on the wire as it goes through the feeder.
Position gun
The gun cable should be kept as straight as possible to allow the wire feeds properly. Softer wire is know to easily bend or twists as a result of feeding restrictions.
How to Weld Aluminum with Torch
A lot of people have troubles welding aluminum material using a torch. Well, if you also belong to this category of men, then this article is for you. Keep reading as this paragraph is going to teach you how to weld aluminum with a torch in three simple steps. But before then make sure you have all the right equipment intact. Get a torch with a pinpoint tip (something like a propane torch).
First Step: Get the Right Equipment.
A good torch and brazing rods are the most important materials you need when welding aluminum. Make sure you invest in the right materials to avoid issues while doing the job. Get a correct torch, a torch with more pin-point would do a better job. Also, aluminum brazing rod with a working temperature of approximately 800 degrees Fahrenheit will be good enough to get you going.
Second step: prepare the area to be welded
Make sure the joint to be welded is well cleaned before heating. Anytime you want to weld metals together ensure that the joint is cleaned off. This is because clean metals stick better to clean metals. Doing this will also make the welds cleaner and stronger. Use a wire brush to clean both surfaces
Final step: Brazing Aluminum
Now you are ready to get heating. Apply the flame on the joint to be welded until the temperature is hot enough to melt the rod. Sweep the tip of the rod through the joint. If the metal is hot enough, the rod will melt, and the joint will fuse. If not, you will need to heat the joint one more time and try again. Once this is done, then wait for the joint to cool. You will have a strong joint.
How to Weld Aluminum with a Stick Welder
In the past, so many people use TIG welding method for aluminum, this method is still widely in use. However, other methods like Stick and MIG welding, are currently gaining popularity. These methods can produce high-quality welds and require less training compared to the so-called famous TIG method. Stick welding method has some advantages over MIG and TIG welding processes in that; the equipment needed for this process are relatively cheaper, you don’t need gas bottles, regulators, torches or other related equipment.
The following steps highlight the process of welding aluminum with a stick.
Step 1: Know the Properties of Aluminum
Aluminum is soft and light in weight, it can easily be cast, formed and welded. Aluminum can easily be combined with other metal by welding. It has excellent thermal and electrical conductivity. Aluminum is highly resistant to corrosion and its melting temperature is relatively low compared to other metals like iron and steel.
Step 2: Cleaning and preparation
Aluminum is easily oxidized to form a thin layer of aluminum oxide in the presence of oxygen in the air. This layer must be cleaned before welding; doing this will help deliver high-quality welds. To prepare aluminum for welding, the surface to be joined can be scraped using a sandpaper or a wire brush.
Step 3: Current and polarity settings
The first thing you need to do is to get your DC SMAW power supply. The current and polarity settings vary slightly depending on the type of electrodes used. Used the manufacturer’s current and polarity specifications. Or more so you can take some few trials on the joint to be made.
Step 4: Joint preparation
The design of welded joints for Aluminum is almost similar to that of steel. But because of the increased fluidity of aluminum under the welding arc, there are some important things one must put into consideration. With lighter gauges of aluminum, less groove spacing is by far better. A V-shaped groove is mostly preferred. This is a type of joint allows to weld from one side only, as such, smooth and high penetrating bead is achieved
Step 5: welding procedure
The stick electrodes are used to create an arc around the joint to be welded; this produces a high amount of heat that melts the metal parts. When melted, the metal gets mixed with a filler and soon joined the two metal parts into one.
When arc welding aluminum with a stick welder, an extruded flux-coated electrode is used with DC Reverse Polarity. The electrodes are covered in the same manner as steel electrodes. The flux-coating helps provide gas shielding around the arc and the molten aluminum puddle, it also combines to form a slag, thereby removing the aluminum oxide.
How to Weld Aluminum with a Spool Gun
Learning how to weld aluminum with a spool gun may require some serious practice in the workshop and not just online training. This is because sometimes things might go wrong, especially with your settings and technique. Therefore you need some time to learn how to regulate the wire speed, amperage, and other key settings. However, we’ve tried our best to put down some of the key tips you need to get started
1. Get the correct Spool gun for your welder.
Most times, aluminum wire easily jams when you are using the wrong spool gun for your welder. I believe you wouldn’t want to waste your time feeding a jammed wire out of your welder! You will do yourself a lot of favor by getting the right spool gun that will make easier to feed the wire.
2. Clean the metal
The first thing you need to do if you want to achieve a high-quality weld with aluminum is to begin by cleaning the joint to be joined. Although sometimes you may get away by not cleaning the metal if it is a brand new and does not have any particles on it, but the best advice is for you to clean it first. You can use an angle grinder or a wire brush for the cleaning purpose to prevent weld contamination. Some professional welders even use acetone to clean off the weld before starting the work.
3. Set the right Gun angle for welding aluminum
For aluminum welding, 10 to 15 degrees is ok to get the job. Any deviation from this could lead to problems with your weld. Note! Attention to the details is a must if you want to maintain proper angle while welding aluminum.
4. Voltage and wire speed control
The amperage and wire speed must be well regulated when welding aluminum with a spool gun. Too High temperature and too much wire will spoil your work and leave you with nothing but a mess you will have to clean up with your angle grinder. It is advisable to use the chart on your welder to test with a few different wire speed and voltage settings before starting the main job.
5. Gas Flow for welding aluminum
To avoid your arc from hissing too much or jumping around, it’s good you correctly adjust the flow of the shielding gas. This is because too much shielding gas will ultimately cool off the weld puddle and as such makes it very hard to maintain a steady, tight arc.
6. The temperature of Metal for welding aluminum.
Investigations have shown that preheating aluminum gives much neater and stronger welds. You may consider preheating the metal a bit prior to sticking your arc especially if you are working in a cold climate. Doing this will make you get the best result ever.
7. Test your settings
When it comes to welding aluminum, even professional welders have to run some few test passes before attempting the main job. Nobody will want to cover his workpiece with spatter and burns the tip right from the start. Hence, it’s very important you test your gas flow, amperage, wire speed and stick out length in the first place to work out the kinks, erratic arc and too much oxidation in the puddle.
8. Wire Stick Out
Just a little extra wire on your tip will go a long way to save you a lot of troubles, and from burning up the tip of your spool gun. The ideal stick-out is around 3/4 inch. Meanwhile, you may need a longer stick out for some other projects. In either case, it is important to point out that too much stick out more than the required will dump too much metal in your puddle, and you may likely lose control of the puddle. This will, in turn, leaves you a bunch of spatters on your workpiece.
How to Weld Aluminum without a Welder
Generally speaking, welding aluminum is not as hard as most of the people thought is. The process is simple and easy to learn. Wondering on whether you can be able to weld aluminum without a welder? Well, we got you covered. This instructable will teach how to weld aluminum without a welder through the following simple steps. All you need to have is your torch, some aluminum brazing rods and nothing more.
1. Get your torch
Most people prefer using Blue Bernzomatic propane torch, but it’s preferred to use a yellow premium torch as it is hotter and works much better and quicker.
2. Brazing rods
Aluminum brazing rods are must-haves whenever you think of welding any kind of aluminum material. Because without it these rods your work done is automatically zero.
3. Cut Aluminum Tubing
Aluminum is a very soft metal; the cutting can be done using the regular woodwork saw blades.
4. Clean the joint to be welded
One important step worth noting is cleaning the joint to be welded. This is very important as it helps deliver cleaner and stronger welds.
5. Heating
Clamp the tubing and then heat up the aluminum using the propane torch. At about 1200 degrees Fahrenheit, aluminum will start to melt, but the brazing rod only melts at about 700 degrees Fahrenheit. The essence of this heating is to get the aluminum hot enough to melt the rod and not the tubing.
6. Braze the Aluminum
Sweep the brazing rod along the joint until it’s filled and the weld formed. Then follow it up with more heating to make the weld stronger. Note: if the aluminum is not hot enough, the brazing rod will only clump up and will not stick to the tubing. You will master the art of welding aluminum without using a welder with patience and constant practice because your first few tries may only be failures and ugly joints.
FAQ
1. What are the settings requirement for welding aluminum?
A: Well, the settings requirement needed to MIG weld aluminum is quite similar for all positions. 21 to 23 volts is enough to get the arc to spray transfer in most cases. If welding out of position, you will need to feed the wire as fast as possible to keep the weld.
2. Is it necessary to use gas to MIG weld aluminum?
A: The answer is yes. This is because the aluminum easily oxidizes in the absence of the gas and you will only be welding the oxide. As such, the weld will only tack, and only the surface became welded.
3. What drive rolls is best for welding aluminum?
A: There are quite several drive rolls designed by various companies. From nylon coated to the push-pull system (which has a small drive motor in the gun). Nevertheless, what matters the most is using the appropriate tip and liner. A bigger tip for aluminum and Plastic for liners. However, most professional welders prefer using quad rollers as they are made to size for aluminum wire.
4. Can I use a wire feed welder to weld aluminum?
A: The truth is yes, you can. However, you need to be extra careful doing such, as a small mistake could damage the aluminum because of its high temperature.
5. When is it proper to stack aluminum beads?
A: Well, this majorly depends on the type of job and the load the weld will be bearing. Aluminum is rarely used for structural jobs. It’s more recommended on structural T-joints and corners. Therefore, you can weld both sides, grind the beads and then lay another bead on top. This is to ensure that the weld holds.
6. What could possibly cause my MIG welds look like surface solder with lots of black soot?
A: Well, this could be caused by so many factors like using an incorrect mixture of shielding gas rather than using pure argon, incorrect gas pressure or volume, or even wrong size shroud.
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