A TIG welder is a multifaceted welding tool capable of performing various activities according to a welder’s demand. But when beginners come into the field, they have a lot to explore what a TIG welder can pull off. Almost all of them have this question: can you braze with a TIG welder? If you can, how? Also, does it do a good job?
You can braze with a TIG welder. It resembles other welding operations but with additional steps requiring you to place the tack filler, pulse the welder for getting control, and prevent the base metal from melting.
TIG brazing is a handy technique for brazing. But using a TIG welder in a workshop is a daunting task. Keep reading on to learn more about brazing, TIG welders, and how you can braze with a TIG welder.
What Is Brazing?
Welding and brazing are pretty relatable to metalworking techniques as they both use a filler metal to create a seam for two connected metal pieces. However, they differ from one another too. Welding requires the fusing of the base with the filler to synthesize. On the other hand, brazing works as molten glue by patching the filler between the joined pieces.
Both techniques need shielding gas like argon. The Welding process is more apt for metals having similar points of melting. But brazing is better suited for joining dissimilar metals.
Luckily, you can do both activities with TIG welders, one of the most versatile gears for Stick as well as MIG welding methods.
Pros & Cons Of Brazing With A TIG Welder
Brazing with a TIG welder definitely has its benefits. But as expected with every other thing, it comes with drawbacks too.
- Precise and high-quality brazing
- Aesthetically pleasing beads
- Satisfying performance on thin metals
- Perfect for dealing with motorcycle frames and different automotive sheet metals
- Capability to work on exotic metals like titanium that conducts electricity
- Difficulty in controlling all the process aspects simultaneously (controlling filler feed, welder travel, and gas flow altogether requires massive focus and dexterity)
- You cannot afford to make mistakes here, which applies to beginners. Any error in the process will lead to unstable and ugly welds.
- The activities are challenging for beginners because they are slow processes requiring high expertise for flawless results.
While it is apparent how benefited you will be from brazing with a TIG welder, I have to stress the point that metalworkers have to conquer a decently sharp learning curve if they want to develop sturdy and good-looking beads.
How To Braze With A TIG Welder?
The process of brazing with a TIG welder consists of a number of steps, which I have to introduce with further explanation. So pay attention while reading them. Any knowledge gap will cause you to create undesired output.
4 Fundamental Components Of Brazing
- Heat Source: It allows the filler ware to get melted for TIZ brazes. You want a very high-temperature rate to melt tungsten, steel, and other similar metals. So, stay cautious around a brazing operation.
- Shielding Gas: Inert gases protect a welder from the surrounding oxidizing elements. You can also use a mixture of argon and helium.
- Welding Torch: A tungsten electrode, a welding cup, a black cap, a collet body, and O-rings, combined, form a welding torch. You can incorporate valves to magnify the flow control, too.
- Filler Wire: The choice of filler wire depends on the type of brazing job. Silicon Bronze is a commonly used filler for brazing purposes.
How To Set The Welding Torch?
- Air-Cooled Torch: You will heat your filler wire here.
- Tungsten Electrode: It protrudes from your welding torch’s end, and it is the heat contact point for your filler wire.
- Collet Body: It is that part of your torch which keeps the tungsten in place. It also acts as the base for your welding cup.
- Welding Cup: It helps keep the shielding gas in the welding pool. It also reduces contamination and oxidation of the brazing operation.
How To Assemble The TIG Welder For A Brazing Project?
- Putting The Tungsten Electrode In The Collet: Do not strip or over-tighten the soft copper threads within your torch. You want to handle your tools gently to sustain their longevity.
- Placing The Back Cap: There will be copper alloy threads on that back cap. So, again, do not strip them. You can use your hand to tighten them. Do not bring in tools to do that.
- Locking In With Collet: The cap and the collet should fit comfortably onto any ending point of the torch. Remember that an O-ring is there to prevent the gas from escaping. Direct it toward the cup instead.
- Installing The Cup: Thread the cup onto the front end of the torch until it rests on the torch insulator.
Now assembling should be over, and the torch should be ready for brazing operations.
How To Prepare The Shield?
- Turning the gas on slowly (Otherwise, the flowmeter gauge ball might crack the tube if you turn on the pressure too quickly.)
- Setting the airflow within the range of 15 and 20 cubic feet/hour
- Keeping the DC amps at 125
- Testing the pedal and ensuring its smooth functioning
Remember to provide 7 to 8 seconds of gas post-flow during operation. It is for avoiding oxidation and protecting the red-hot tungsten when it cools down. When the arcs are out, leave the post-flow over the material.
How To Handle A TIG Welder For Brazing?
It is crucial to note that it is a forward procedure to braze. You have to push (NOT pull) the tungsten electrode through your weld pool.
When using a TIG welder, dragging your tungsten will make the welds vulnerable to the Venturi effect. That can increase the joint porosity. That will produce unstable brazes.
Instead, you need to push your torch vertically at 10 to 15 degrees. Righthanded welders have to shift to left from right, and vice versa for lefties.
Compress your foot pedal to initiate the welding arc. Some torches might require you to scratch or tap start, while others might not.
How To Set The Filler Wire For Brazing?
Remember I told you that using a TIG welder for brazing asks for additional steps? Now I am going to explain them to you.
Introducing The Filler Wire:
It lies on the weld pool’s leading edge. Each contact will leave rounded marks in the braze. The final effect of the look is known as “Stacking Dimes.” The contact marks need to be congruous in spacing and size for perfect brazes.
Be careful not to melt the wire with your arc. Also, do not let it drop into the base metal. That will minimize control dramatically and increase the possibility of molten metal’s random drips getting left beside the seam. That would be a terrible waste of your filler.
Leave tacks on the corners. You can try tacking bits of the wire into those corners to join the metal pieces quickly before carrying on with the seam. That will keep them stable enough to allow you to work without holding them and continuing your job at the same time.
Leaving The Wire In The Weld Pool:
Some techniques need the wire put into the weld puddle’s front. But you have to use some lay wire method and put the filler always on the pool’s front page for solid brazes.
Preventing The Metal Base From Melting:
There is a reason a welder needs to put an additional wire in their braze without dabbing it. It is to prevent contact between the base metal and the torch. Ideally, the torch’s heat should affect the filler only, not its base.
Apply pulse functionality for precision:
Two pulses/second will give you more control. And it helps keep the pool stay cool, reducing overheating.
Adding The Correct Amount Of Wire:
The wire diameter is the rough amount of wire you should push into the pool. Using more may cause a bulky seam, and using less puts the torch at the risky position of burning through your filler into its base.
What Type Of Tungsten Is Suitable For Using A TIG Welder For Brazing?
The suitable one is a 3/32” tungsten with a sharpening point of 30 degrees. It will produce the best arc strikes having low burn-off points, helping the electrode last longer.
That is a huge advantage considering how expensive it is to stock tungsten in your workplace as a rare resource of metal.
How Far Is The Tungsten Supposed To Plug Away From The Welding Cup?
It is paramount to know the measurement because (i.e., 9/16”) is the highest length of the tungsten you expect protruding from your torch’s end.
The standard will assist you in controlling the TIG torch while increasing the braze quality at the same time.
What Are The Problems In Assembling TIG Welders?
The most common problem occurs when you cannot keep the tungsten tight in the collet. It is resultant of threading the cap without seating the collet and electrode in the TIG torch first.
You cannot solve it by tightening it down the cap or cup. The only way to fix it is by loosening that cap, seating the electrode in the collet correctly, and retightening the cap afterward.
The other problem is not understanding the cup measurement. The size of a welding cup comes with a single number (i.e., 9). The number tells you the width of your cup. For example, a 9 cup means the diameter is 9/16 of an inch.
Leaving Some TIPS!
Enjoy the free tips to get the best results from TIG brazing.
- Consistency Of Travel Speed: The torch’s travel speed determines the bead width. If you do not keep it consistent, the brazes will look inconsistent.
- Faster Speed: Faster travel speeds equal narrower beads. If you move too quickly with your torch, it may lower the weld integrity. It will also create a lack of filler spread around the seam.
- Slower Speed: Moving the torch at a slower pace will increase the bead’s heat-affected zone’s side, leading to porosity and discoloring of the seam. As you saw, too fast or too slow speed rates impact the beads badly. So, keep it consistent. Determining that will come easy as you progress as a welder. Try practicing beads on scraps till then to get an idea of how quickly you should move the torch around the base.
Compared to some brazing types, using TIG torches is somewhat complicated and sounds like a hectic job to novice welders. And I will not argue. It does require a lot of experience and practice to master this art.
Nevertheless, using TIG torches is the most versatile method of brazing. Besides, it is worth the time and effort. So, do not give up and keep practicing until you become the best.
All the best!