TIG welding is a versatile form of metalworking and can be applied to a wide array of different metal types, including exotic metals, but it is most well-known for being suited to welding metals of thinner thicknesses, such as aluminum sheet metal. TIG welders allow metalworkers to weld in a variety of positions.
But can you TIG weld upside down on aluminum? The answer is yes, aluminum can be welded with a TIG torch upside down, provided the metalworker is working from a position of stability and has a method to control the torch while working overhead.
Welding with a TIG torch on a piece of metal in the overhead position can be difficult if you don’t know what you’re doing. Read on to find out how a TIG torch can accomplish this task and the steps you need to take to pull it off.
Welding Aluminum with a TIG Torch
Welding aluminum can be performed with a TIG torch, but there are several factors that have to be taken into consideration before doing it. Welding aluminum brings with it a specific set of challenges that can make it difficult to weld on, such as the following:
- Oxidation: Aluminum oxidizes, and this layer of oxidation does not melt until 3,700F. This layer of oxidation helps with the anti-corrosion properties of aluminum but can make welding conduction difficult. This oxidized layer must be removed in order to weld.
- Low melting point: Aluminum has a low melting point of 1,221F, especially in comparison to steel, which is 2,500. Aluminum’s low melting point can make precise heat input control vital for a successful weld.
- Hydrogen absorption: When aluminum is liquified, it absorbs hydrogen very easily. Melted aluminum and filler metal can trap hydrogen gas from the atmosphere during welding, which then forms bubbles in the cooled metal. This leads to porosity.
Welding Upside Down
Welding upside down, or in an overhead position, can be especially tricky when you’re trying to weld aluminum.
The low melting point of the aluminum means you have to worry about it dripping onto the floor if you don’t control your heat and filler well, it is difficult to work precisely when you’re having to work in a contorted position, making ergonomics a factor.
It can also be hard to figure out how to control the TIG pedal from an upside-down position, which can nevertheless be accomplished in a few different ways with planning, practice, and careful work.
Welding with AC Current on a TIG Torch
While it is more common to find TIG torches being operated with a DC current, welding with AC current is necessary to work an aluminum weld. Many professional-grade TIG torches are capable of both AC and DC current conversion.
AC current is necessary for an aluminum weld because using AC current with the welder allows it to clean away the layer of aluminum oxide on the outside of a piece of aluminum, which has a much higher melting point than the aluminum underneath and must be cleared away in order to start an effective weld pool.
When welding aluminum upside down with a TIG torch, it’s important to remember to buy a TIG torch that has AC current settings and doesn’t just operate on DC current. To weld aluminum with a TIG, you’ll need the right tool for the job.
Methods of Pedal Control While Welding Aluminum Upside Down
One of the hardest parts of doing a TIG weld upside down is figuring out how to control the pedal. This can be accomplished in one of two ways:
- Set up a platform or pedal holder. If you have to work overhead while in a standing or otherwise contorted position, you’ll need to set up scaffolding or some kind of platform to position your pedal so that you can reach it. A pedal holder can hold the pedal at a useful angle.
- Purchase a finger control. Remote TIG controls allow you to maintain control over your amperage regardless of your positioning while you weld.
- Have an assistant work the pedal. If you’re having to hang upside down during a weld and have no access to the foot pedal and can’t use a finger control, you can have an assistant work the pedal in response to your amperage requests.
Finger-Controlled TIG Torches
Probably the best (if perhaps the most expensive) option for welding aluminum is to invest in a remote or finger control for your TIG setup. While this can be a somewhat costly investment for the shop, it can pay for itself in high-precision welds and not having to weld while simultaneously pretending you’re in a game of Twister to reach your pedal.
Because aluminum is so touchy to weld with and has specific requirements for a decent end result, you’ll want to give yourself as much control over the TIG torch as you can get. Once the aluminum oxide layer on a piece is broken through, the aluminum melts quickly, so controlling the weld is crucial.
Tips for a Better TIG Weld with Aluminum
Other than making sure you have good control over your heat input and making sure you’re using the correct current, there are some other things you can do to make sure you get a good TIG weld with aluminum. Follow these tips to get a better resulting weld:
- Watch your filler rod. Be sure to keep it out of the heat to avoid having the aluminum puddle begin dripping downward onto the floor. This is a particular danger while welding upside down since once aluminum begins to melt, it melts quickly.
- Use adjustable frequency control. Many of the higher grade TIG models come with adjustable frequency controls, and using them can result in a more tightly focused arc.
- Pulse welding. One of the best ways to control a TIG welder is through pulse welding, which many TIG models come equipped for. Pulse welding allows the aluminum to cool between pulses and decreases the build-up of heat-affected areas that can make the weld become less precise as it goes on.
Methods for Learning to TIG Weld Upside Down
As with any specialized welding tactic, there are a few different ways you can go about learning how to do it overhead or while positioned upside down.
The most obvious way to learn how to TIG weld aluminum upside down is to practice over and over again. Welding is a skilled craft, and the accumulation of skill requires repeat experience. So grab a pile of scrap metal and start welding until you get a feel for it.
Another way to learn tricks on how to TIG weld is to learn from an expert. There are many experienced welders out there willing to impart some knowledge, so never be embarrassed to ask someone with more technical experience for help or a demonstration. You might learn something you’ll use for the rest of your welding career.
Another method of learning about how to do upside down aluminum welding with a TIG torch (or any other kind of welding) is to join a few niche welding forums online, such as WeldingWeb, and ask around. Welding boards are full of enthusiasts who are happy to help you with whatever your ongoing project is, and joining an online community of welders can be rewarding in other ways too.
Practice Makes Perfect When It Comes to TIG
TIG welding is one of the most well-respected welding arts because it can be regarded as more difficult to learn or master than other types of welding. However, its utility with thin materials and the precise welding it is capable of makes it perfect for working with aluminum as long as some basic requirements are met.
With a few extra control adjustments and lots of practice, welding aluminum with a TIG torch upside down or in any other position can be a snap.