How to Weld Aluminum[MIG TIG] Complete Guide – My Welding Yard

Everything About Welding Aluminum You Need to Know, welding aluminum with steel,copper

Aluminum welding is a nightmare for many welders, and they are always frustrated about it; well, in this article, You will know How to weld aluminum. It is a very silvery-white, non-corrosive lightweight metal used in fabrication that makes this metal an ideal material choice in welding processes. This metal is widely used in many products, including drinks cans, kitchen utensils, and some airplane parts, because of its specific properties.

Aluminum metal has a sensitive nature, and a tough oxidized layer insulates it. Aluminum metal is difficult to weld because of its softness, and it is highly susceptible to impurities, which may lead to weak welds. Some factors that make welding aluminum difficult include contaminants, porousness, thickness, and oxidation.

This post is going to be very detailed, so fasten your seatbelts and let’s sink into the aluminum welding secrets and almost everything related to it.

Aluminum with Tig Welding

Tig welding requires a tungsten electrode (non-consumable), clean surface to remove oxides buildup on aluminum (the oxides have high melting points than that of aluminum that’s why there is a need to remove them before we start welding) and lastly, a shielding gas (often used argon).

A foot current is also necessary because of heat generation at the start of welding so that less heat is required from the electrode towards the end of the weld. For better results, use alternating current at a high frequency because they do not contact aluminum and reduce contamination.

how to weld aluminum

TIG aluminum welding is suitable for thinner pieces of the metal. Electrode tip shape for AC welding is “ball” ranging in diameter of 1-1.5 times the tungsten electrode’s diameter. Check the best tig welder for aluminum.

Aluminum with MIG Welding

To weld aluminum with MIG is very different and challenging, and the following should be kept in mind when MIG welding aluminum for the application.

  • Consider the metal’s thickness as MIG is for thick metal pieces with MIG you can weld 14 gauge and more rotund. To MIG weld aluminum thinner than 14-gauge, one can use AC TIG welding equipment.
  • Before welding, aluminum must be thoroughly cleaned and should be removed from any lubricant. For oxide removal, use a stainless wire brush. Aluminum requires 100% argon shielding gas as its non-ferrous metal with a 20-30 cubic feet flow rate per hour.
  • One should know the alloy of base aluminum and the finished part which is being subjected. Filler wires ER4043 and ER5356 are the best filler wires for MIG welding.

The desired mode is spray transfer. It is a smooth transfer of molten metal droplets from the end of the electrode to the molten pool. The droplets crossing the arc are smaller than the electrode. Always bear in mind that a compatible MIG welder is necessary for this Kind of operation.

MIG welding’s advantage is that there is no short-circuiting in spray transfer with a high deposition rate and relatively high efficiency. Choosing a gun or wire feeding system is an essential step before performing MIG welding aluminum.

Welding aluminum with Stick Welder

Stick welding is a bit messy process in which a heavily dipped electrode is used with DCRP (DC reverse polarity). Before starting welding, heat the aluminum metal first because a cold metal will not give us good results.

Its other name is shield metal arc welding, which is very easy to perform and inexpensive. This type of welding technique is often limited to small fabrication shops but can be used to weld aluminum smoothly. Consider these stick welders for aluminum.

We might have to weld aluminum in different forms. Here are some things to remember:

Welding an Aluminum Alloy

Not all alloys are to be weld with gas tungsten, arc welding, or gas metal arc welding. Every alloy has a unique characteristic. The aluminum alloys are of two types, heat treatable and non-heat-treatable. The second type of alloy is hardened through a cold working technique that makes the metal stronger.

The first type of alloy is treated at 400-degree Fahrenheit. If no heat treatment is done before welding, the welded area will be around 35-40 % weaker than the rest of the aluminum metal. Arc welding is the most commonly used technique for joining aluminum alloys.

Welding Aluminum alloys with steel

Welding aluminum alloys with steel are different from pure aluminum welding. Aluminum alloys can be joined to steel with brazing techniques, using mechanical fasteners and adhesive bonding. A thin layer of non-absorbent insulate is added between aluminum and steel when it comes into contact.

Plastics and rubber can be used for this purpose depending upon the application. Alternatively, we can prime the parts with a protective coating or can use polypropylene tape for insulation. The fusion of aluminum and steel is complicated due to different properties like dissimilar melting points, expansion coefficients, and thermal conductivity.

For joining these two metals use lasers, top create joint seems a logical step. The main focus is to keep the temperature as cold as possible and minimize the weld’s exposure time to high heating. That’s why friction welding is being used to generate bimetallic transition inserts between aluminum alloy and steel components.

Aluminum AC lines Welding

  • Apply powder flux on the base metal.
  • Pre-heat the base metal well. The main objective is to heat the most significant part of the metal, moving the heat from each side.
  • When you notice all the powder turns into a liquid state, this indicates 600-degree Fahrenheit temperature.
  • Now deposit the welding rod.
  • Apply the rod carefully, in such a manner by keeping the heat source to avoid burning the flux. For better flow, you can apply more flux.
  • When you are done with one side, apply it on the other side as well.
  • For the removal of flux, use lukewarm water, and the part is ready for installation in the vehicle.

Welding Aluminum alloy wheels

Suppose the aluminum wheels crack easily when hit strongly. For welding an aluminum cracked wheel, one should know some critical issues related to the aluminum alloy wheel, like the crack’s location, the direction of the damage, and the welder’s skill. If the damage is inside the barrel, it should not be welded.

The crack on the wheel’s backside crosses the flange and bead area at the right angle in wheel spins. Such damages can be welded. The fissure in parallel to the spin direction is not suitable for welding by making the wheel unbalanced at the welding area. Hence, the wheel will not run in a straight path.

Welding Aluminum With Copper

Both aluminum and copper metals cannot be welded together through direct contact because no bond is formed between them. For connection of these metals, one should use the proper connection method, avoiding direct contact. The main reason is that both metals corrode from galvanic action, and eventually, this act can cause a fire.

aluminum copper welding

Aluminum and copper are welded through a solid-state process in which we heat the metals at specific points. When they become soft, these metals are subjected to join. The most favorable method for aluminum copper welding is ultrasonic metal welding, where material vibrates parallel to the welding point so that heat is produced through surface friction. However, soldering is the best method to weld aluminum and copper.

Welding Aluminum and Carbon Steel:

One of the methods for welding these two metals is coating the steel with aluminum. The coating can be achieved through dip coating or by brazing the aluminum on the steel’s surface. When the layer is done, both metals can be arc welded. Proper care should be done to prevent the arc from infringing.

Welding aluminum and steel

Both metals have different metallurgy and different melting points. Carbon steel melts at 2500-degree Fahrenheit while aluminum melts at 1218-degree Fahrenheit. Because of this difference in melting points, arc welding will create a brittle compound with weak fusion. The only way to weld both is through solid-state welding, in which amalgamation takes place at room temperature below the melting points of the metal being fused.

Welding Aluminum-Bronze

Aluminum bronze is also an alloy with almost 12% aluminum, 5-6% iron and nickel metal, and copper. Aluminum copper welding can be done through the MIG welding technique. Argon gas and aluminum-copper core are required for welding.

Welding Anodized aluminum:

The parts of the aluminum should be welded before anodizing. The welding process requires electrical conductivity. Once anodizing is done, the aluminum metal will become non-conductive, so do not anodize aluminum before welding. The best alternative is grinding the area.

It is possible to weld aluminum after anodizing, but it is a very complicated process and challenging and not suitable for amateurs. For this use, power supply at maximum output current during welding, energize the arc just enough to create a puddle. Now add bead filler and shut off the power supply. Move over almost half the weld puddle diameter and keep repeating.

Applications of Aluminum Welding

These methods of welding aluminum can be used in various practical life areas.

 Aluminum Gas tank

Don’t use argon gas in the welding gas tank through MIG because it results in suffocation, ensuring no fuel or fumes in the gas tank. All welding processes should be according to safety standards and meet the required specifications. Before starting welding wash out the gas tank entirely with warm soapy water and then wash it with clear water. In removing fumes, small pieces of dry ice in the neck of the gas tank are used.

Aluminum can be welded using a milling machine with a specific FSW tool, which creates a unique joint invisible to X-rays. There is no need for any gas or heat in this process. It was used for making aluminum tanks for space vehicles. This type of welding gives as much strong weld as the base metal. This process is also called “friction stir welding.”

Aluminum Gutters

To weld aluminum gutters, firmly press both ends of the gutters so that both are closed together. Use a high-wattage, and place the soldier against the joint with a hand-held torch. After the metal is thoroughly heated, the solder melts along the joint. Keep in the notice that does not drill holes in the bottom side of the gutter.

Aluminum Evaporator Coil

When a leak occurs in aluminum evaporator coils, what should we prefer to either replace or repair them? The practical and cost-effective solution uses Handy One AL 822 brazing alloy because the traditional aluminum-silicon alloy starts melting close to the base metal melting point.

The recommended AL 822 melts lower the melting point of the base metal. This tool is a fluxed cored brazing alloy, so there is no need for other fluxes. In the center of the rod, a non-corrosive flux is generated. Now at that point, you can fill the repair.

Aluminum Engine Case

There are many ways to weld aluminum engine cases like it can be done with a stick welder, TIG welder, and MIG welded. These engine cases can also be welded by a gas process named aluminum brazing. But significant difficulties in case repairing are the high thermal conductivity and the low melting point of metal due to which distortion occurs.

Aluminum Exhaust

The best technique to weld aluminum exhaust is MIG welding. This welding is generally used for welding the exhaust system of the vehicles. The exhaust systems are often constructed with thin metals to keep them low in weight, making MIG welding the most suitable.

Welding Extruded Aluminum

Avoid all types of 7075 welding series in case of extruded aluminum. Arc welding is not suitable for aluminum. Extruded aluminum is also one of them. We cannot weld the alloys in the 2XXX and 7XXX through the arc.

Aluminum Engine

If the engine crankcase is made up of cast aluminum, you cannot weld it because of aluminum’s shallow melting point. The only possible way is to repair a hole or a crack in the engine’s crankcase. Moreover, engine repair costs are very high.

Aluminum Engine block

Aluminum engine blocks can be welded with TIG or MIG with 4043 filler wires. This filler will be preferable in TIG welding as one can have more control over it. Its welding is like that of cast aluminum. When dealing with aluminum welding, a temperature higher than 150 Fahrenheit is reviewed as a high temperature.

Aluminum Rims

  • Clean the wheel rims with a washing liquid to erase all the dirt and grease.
  • Now sand down the damaged part to eliminate any obtrude area. Smooth the surface by using finer sandpaper and let the rim be dry.
  • After that, fill the damaged portion. If you are using filler spray, spray it into the damaged area. Let the filler to set in.
  • Finally, conceal the damaged part before you paint. Apply the paint in thin coats and leave it to dry.

Aluminum Radiator

You can weld cracks or holes aluminum radiator through JB weld, super alloy 1, aluminum radiator repair epoxy, and soldering aluminum radiator.

Aluminum Rods

Aluminum welding rods play the role of filler material in welding. When you are welding two metal pieces with a torch’s help or using electrical current, these rods melt to fuse both elements. But remember that you cannot join dissimilar metals.

Aluminum Bike frame

When you try to weld aluminum, it cannot be re-welded with its original strength like steel. Replacing bike frames is better than repairing them.

Frequently Asked Questions FAQs

Can you weld an aluminum block?

Heat the area to a temperature not so strong to warp it, bezel out the piece to go back on. TIG can prove useful for welding aluminum blocks.

Can you Weld Aluminium Boat Hull?

When you have to weld an aluminum boat or repair it, the only possible option for this TIG welding or MIG welding is to use a stick welder. Any negligence may prove fatal if your boat starts taking on water at sea. So strong welding is required in the boat hull.

Can aluminum body panels be repaired?

In the case of welding aluminum body panels, use MIG welding with shielding gas. That’s a good option for welding automotive body panels. It isn’t easy to straighten out the welded panels because expansion heat distorts the closely fitted metal edges very severely.

Can you weld a cracked bell housing?

When the question arises about welding a cracked bell housing, no doubt you can do it with TIG welding. The main reason for the cracking of bell housing is worn transmission and excessive vibration from the engine mounts.  Replace it as soon as possible.

Final Verdict

I am glad you made it. I have put a lot of effort in writing this guide and almost everything related to aluminum is now in one place I hope you will like it also if you feel something is wrong or misinterpreted then you can write in the comment section. Thanks

Hello Everyone, I am James from Kentucky and been into this welding fiasco for 13 years in that time I have worked as a private welder and did most of the auto restoration work. In this recent, COVID-19 outbreak I decided to start a welding blog and share welding tips along with product reviews.

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