TIG Welding
TIG (Tungsten inert gas) welding is available at the Roundhouse after being certified on our equipment thorugh taking our TIG Welding class. The following page is a collection of resources to help members prepare for the class and to reference in the future.
A brazed joint is made in a completely different manner from a welded joint. The first big difference is in temperature – brazing does not melt the base metals. This means that brazing temperatures are invariably lower than the melting points of the base metals.
Equipment
Safety Equipment
TIG Welding gloves are more dextrous than MIG gloves. They are designed to protect from radiant heat, NOT splatter
Torch
The cup / nozzle focuses the inert gas onto the material and prevents oxidation.
Different materials: ($2-3) ceramic, ($6) pyrex
Different sizes; if thin metal, use smaller nozzle to focus the gas 8/32, 12/32, 16/32 === 4, 5, 6 sizes cup
Cullet - holds the tungsten rod; has a split in it to press into the tungsten rod to hold it;
Has different sizes too; if too large, tungsten can be loose and wiggle.
Cullet body - holds the cullet
Tungsten electrodes
Different size — if welding small = 2/32, medium = 3/32, large = 4/32; Size of nozzle is 4-5x tungsten
Different annoys for better starts / Ideal temperature ranges; standard: Standard: Lanthanum - standard 2%; Cerium
Note: Used to use Thorium — but that’s radioactive, so don’t use that
Different colors indicate different materials
Electrode stickout (distance from the surface)
TIG electrodes need to be sharpened to prepare for welding. The angle of the tip influences the properties of the arc.
Filler Rod
Generally same size at tungsten; Need to select the correct alloy based on the material you're using.
Some can be anodized; some cannot;
Power / Inverter
Selecting the correct power settings is a trial and error process, but can be guided by reference tables.
"DC" (Direct Current) TIG welding machines can be used to weld a variety of "ferrous metals" including mild steel & stainless steel, and also copper and chrome moly. (But NOT aluminium). To weld aluminium, you need a machine with "AC" (Alternating Current) capability.
TIG welding process
Travel angle refers to employing either a push angle (pointing in the direction of travel) or a drag angle, when the electrode is pointed opposite of travel.
The travel angle is 90 degrees
The travel angle is 45 degrees
Work angle is “the relationship between the axis of the electrode to the welders work piece”.
The work angle is 15 degrees
Brazing
Brazing for TIG (Tungsten Inert Gas) welding is a joining process where a filler metal with a lower melting point than the base metals is used to bond them. The TIG torch provides heat, while the non-consumable tungsten electrode remains unaltered. As the base metals reach the brazing temperature, the filler metal flows between them, forming a strong, durable joint.
Brazing differs from welding as it joins metals using a lower melting point filler metal, typically below the base metal's melting point. Welding, on the other hand, fuses metals together by melting the base metals themselves, often requiring similar or identical melting points. Brazing results in a stronger joint with minimal distortion and allows for joining dissimilar metals, while welding creates a more integral bond but may cause more significant heat-affected zones.
Aluminum Welding
Problems / Observation >> Possible cause >> Solution
High zappy electricity but not starting arc The full current isn’t flowing Make sure the clamp is attached to the table
Arc not forming Metal unclean Use new or clean metal; use a brush or a grinder to get down to clean metal;
Weld is all black and smoky Shielding gas is not protecting the weld Turn the gas on; turn on; Keep the nozzle at the weld longer after turning off the weld
Tungsten rod is getting black Insufficient shielding gas Turn up gas; turn up the post flow
Tungsten stuck to the material You went too close Move back a bit; goal is 1/16 inch
Puddle is taking very long to form; rest of material getting very hot Amperage too low Put up amperage
Puddle forming very quickly Amperage too high Lower amperage to a range you can handle
Puddle not forming (want to be at ~2 seconds) Not enough amperage Turn up max amperage; Press harder on the peddle
‘Turds’ are forming Putting filler metal in the puddle too quickly Establish a larger puddle before adding the filler rod