00:00 |
- Almost all metals can be TIG welded but the procedure from producing a high quality professional weld differs a little between material types and each requires a few setup and setting changes which we've outlined in detail in the material specific section of this course.
|
00:16 |
These material specific modules dive deep into the best practices for working with different materials and give a complete list of baseline settings to get yourself started so make sure that you check out the relevant module before launching into a project.
|
00:30 |
Regardless what material you're welding, it's important to first test out our technique and welder settings.
|
00:37 |
The best way to do this is to grab some scrap metal and begin setting up for a series of test welds.
|
00:42 |
Before striking an arc for the first time, we should first complete what's called a dry run.
|
00:48 |
By moving through the motions in a dry run, we move the torch over the intended weld area without striking an arc.
|
00:55 |
This gives us a really good idea of where we should position our test piece and what supports we can incorporate into our setup to make for a smoother weld motion.
|
01:04 |
Before we go any further, let's talk about the grip that we have on the torch, comfort is critical when we want to produce a consistent quality weld and by holding the TIG torch like a pencil, this gives us additional maneuvrability with the torch head.
|
01:19 |
The angle of our torch is also important here, we want to tilt the torch so that the tungsten is angled in the direction that we're travelling at approximately a 15° angle.
|
01:30 |
This will allow us to introduce the filler rod into the weld pool directly in the stream of inert gas.
|
01:37 |
For 90° corner welds, we want to have the torch at a 45° angle to the corner which means that we're favouring both edges of the weld evenly, while still maintaining the 15° angle in the direction of travel.
|
01:51 |
You might be holding the torch correctly and have the angle right but one of the harder things to learn when TIG welding is maintaining the correct distance between the tungsten and the work piece.
|
02:02 |
We typically have it in the range of 3 to 5 mm away from the weld pool and it can take a lot of practice to control this arc length.
|
02:11 |
Keeping it as short as you can without allowing the electrode to touch the base metal or the filler rod.
|
02:17 |
It can also be beneficial to slightly open up the arc by lifting the torch when introducing the filler rod into the weld pool.
|
02:24 |
With our dominant hand directing the TIG torch, our other hand will be adding in the filler rod.
|
02:29 |
When initiating the arc, we need to spend a moment getting heat into the part.
|
02:34 |
The thicker it is, the longer we have until the weld pool forms.
|
02:38 |
This weld pool is recognised as a wetting of the material and should have a bright lustre as it becomes fluid.
|
02:45 |
Once the weld pool has formed, we can begin adding the filler rod and moving the torch along the weld.
|
02:51 |
The motion of dipping the filler rod must be carried out within the protected area of our gas stream.
|
02:57 |
As soon as we dab the filler rod into the molten weld pool and begin to move along our weld, it's important to keep the tip of the filler in this protected zone so that the filler rod material isn't contaminated by the atmosphere while it's still hot.
|
03:11 |
This is easy to overlook and initially you'll often find you're pulling the filler rod back out of that shielding gas flow.
|
03:19 |
Just concentrating on making small movements and keeping the proximity to the arc close will help this.
|
03:26 |
This brings us to the actual process of feeding the filler rod into the weld.
|
03:30 |
By using a combination of your thumb, index finger and middle finger, we can learn to feed the filler rod into the weld pool, while maintaining excellent control of the filler rod.
|
03:40 |
The aim here is timing your filler rod inclusion and the amount of filler rod you add.
|
03:46 |
These two aspects will have the largest effect on the size and consistency of your weld bead and practice here is the key to perfection.
|
03:54 |
The technique just covered is really all most welders will ever need to worry about, however for specialist alloy welders who spend a lot of time performing long weld runs, learning to feed the filler rod through your hand while also simultaneously adding the filler rod to the weld pool is important.
|
04:13 |
This is of course because as we add the filler rod to the weld, the filler rod is consumed, becoming shorter.
|
04:20 |
Unless we can also feed the filler rod through our hand while we're adding it into the weld pool, sooner or later, we're going to run out of filler rod which will require us to stop the weld in order to reposition the filler rod through our hand again.
|
04:32 |
We mention this for the sake of completeness but I do want to stress that this is an advanced technique that even many professional fabricators can't perform consistently so don't beat yourself up about it.
|
04:44 |
For most of us, stopping the weld to reposition and reset the filler rod in our hand is absolutely fine.
|
04:51 |
It's common to get a little complacent and forget about the torch position when we are learning to weld so remember to keep the arc length as short as possible and favour both halves of the material that you're welding equally.
|
05:03 |
One exception to this rule is when we're welding a thicker material to a thinner one.
|
05:08 |
In this case, we should be focusing the majority of our heat input into the thicker material and only spend just the required amount of time moving this heat into the thinner material in order to produce the desired weld.
|
05:21 |
We've already stressed the importance of preparation but beyond that, the welding technique is really the key to your welding success so this is something you're simply going to need to put the time into practicing until it becomes second nature to you.
|
05:34 |
At first, it will likely feel a little like trying to rub your belly with one hand while patting your head with the other but time on the torch will commit these actions to muscle memory which is when you can really start laying down weld beads that you can be proud of.
|
05:49 |
There's no way to rush this learning curve and you need to commit the time to practicing it.
|