Tig Welding Test

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There are all sorts of tig welding tests for pipe welding that involve a tig root pass and hot pass...with a stick fill and cap.

This is a very common tig welding test that comes in all sizes and thicknesses...and in different material types.

You could break the bank trying to buy all the different sizes of pipe to get some practice before going to take a tig welding certification test.

Since a large percentage of tig welding tests are on carbon steel, one way to get some practice is to just get some 3/16 " thick cold or hot rolled steel flat bar that is 2-4 inches wide and about 8 inches long.

I made a video recently showing how a corner joint with a 1/8" gap could be used to simulate a pipe root gap and explained how the same mig welding settings and mig techniques could be used to weld the inside corner joint as was used on a open butt pipe weld.

Well guess what! The same joint is a great way to practice your technique before heading out for parts unknown to take a tig welding test.

I dont know about you, but I dont like driving for 15 hours to stay in some flea bag motel only to get up the next morning to fail a welding test because I didnt get any practice.

Its depressing, and humbling.

I would much rather feel some little bit of confidence from doing something close like a mock up ...if not the exact test.

The exact test is usually impossible to practice. But what if you could set up a mock up and use the amperage setting that worked for your test??

Would that give you an edge? I think so.

A corner joint using 3/16" 1/4", 3/8" thick carbon steel can provide experience, and is a confidence builder....and its cheap compared to buying beveled pipe welding coupons.

I get emails frequently from welders who are either going to a school that does not have beveled plates, or they are practicing on their own with plate or pipe they bevel themselves with a grinder.

So I figured I would share a practice joint that gives some real good practice. Also, I had acess to a few beveled plates.

You can order beveled plates from Triangle Engineering for a reasonable price...(roughly 7 bucks depending on current steel prices).

The bevels are coated with a special paint that you can weld over if you want..the paint is called Deoxaluminite.

Welding Steel

Steel is basically Iron and Carbon with small amounts of other stuff like manganese. Low Carbon Steel has .3 percent carbon. Not 3 percent but 0.3 percent or point 3 percent. That’s not much. For comparison sake, Cast iron has a full 3 percent and sometimes more. That’s why cast iron is such a pain to weld and also why low carbon steel is the easiest metal to weld… low carbon steel is also the cheapest metal to buy. Low Carbon Steel is what we use to learn to weld and low Carbon steel is what we compare all other metals to when we study metals. Why? Well it’s easier to understand stuff if we can compare it to something we already know and understand. How you gonna weld anything else if you haven't learned welding steel?

Stick Welding steel

Stick welding uses stick electrodes with flux baked on them. Stick welding is used on the farm, and on construction sites and in the field like on a pipeline. It still rules as the most commonly used type of welding in the world. Its portable, the equipment is simple and cheap, and windy conditions don’t much matter because the flux on the rod turns into slag that protects the weld from air.In the hands of a craftsman, stick welding can produce some high quality welds. Its easy to change from carbon steel to stainless steel…all you do is change rods.I have actually had folks ask me: Does anyone really still use stick welding? Then I explain to them that the arc they see from a distance on a high rise construction job, is most likely stick welding.All you need to know about stick welding rods is 6011 and 7018. They both run on a/c or dc reverse so a 225 amp Lincoln buzz box from home depot is all you really need for a whole lot of hobby welding.
6011 penetrates deeper and can weld downhill. 7018 will look better but they suck for downhill. A 7018 bead done by a good welder looks good and is ductile and strong.

Aluminum Welding Settings

1.wire feed speed : aluminum welding with a spool gun is very sensitive to wire feed speed. Slightly too much wire feed speed and the arc is not smooth. A smooth humming or hissing spray transfer is the goal with little or no sputtering sound. But just slightly not enough wire speed and the wire tries to burn back to the tip. Once that happens, you need to change tips.
2. Stickout: with mig welding steel using spray transer, , a short stickout is the way to go. A longer stickout is needed for Aluminum Welding with mig. about 3/4" seems to work, but sometimes slightly more works better.
3. gun angle: push, dont pull. pushing the puddle with a 10-15 degree gun angle is what works. Pulling makes for a sooty weld. Sometimes the weld is ok inside, and the soot can be wire brushed easily. But sometimes pulling causes oxides to be trapped in the puddle and causes porous welds.
4. cleanliness of metal: I will get some arguments on this one. If the metal is new and clean and free of oils. A good weld can be made without any cleaning. I will repeat that just in case someone thinks its a typo. If the metal is new and clean and free of oils. A good weld can be made without any cleaning.
If the metal is not new and has been outside growing a thick layer of oxidation, wire brushing with a stainless wire brush, or even some type of abrasive wheel that does not leave residue might help a lot. If the aluminum is heavily oxidized like you might find on a part subjected to salt air or water, cleaning with an abrasive wheel is a must, followed by an acetone or alcohol wipe...I prefer acetone.
5. gas flow: the rate of gas coming out of the mig gun is set at the flowmeter. With steel, enough is enough but more than enough usually does not do any harm until you get really high. Its just wasteful. But for mig welding aluminum, gas flow rate makes a lot of difference,. Too little flow, and the weld will be sooty with specks of black oxidation in the weld. Too much, and the puddle gets very erratic. The arc has trouble heating and melting the metal with all that cool argon blowing on it. The arc will often be very loud with lots of fine freeze lines and ripples in the bead.
6. purity of gas: Slightly contaminated gas, whether contaminated in the cylinder or as it comes out the mig nozzle sometimes goes unnoticed on steel. Its very forgiving. A slight leak in a connection, a pinhole in a gas hose, or moisture in the argon can all cause plenty of problems for aluminum welding with mig.
7. using a clean contact tip: aluminum mig wire is soft. any burrs on the contact tip can restrict wire feed and cause problems.
8. ground: A good ground is important with any mig welding job but especially important when migging aluminum. Also , make sure the aluminum part you are welding has a direct ground because arcing can dig deep and cause lots of damage...especially to machined surfaces.
9. internal inductance setting of power source: not all mig welding power sources are specifically designed for aluminum welding. Every mig welder has either an inductance setting knob...or an internal preset inductance. Inductance affects whether an arc is soft and sweet or harsh and digging, or somewhere in between. That is why finding the sweet spot settings for aluminum mig welding can be hard.
For higher end machines that were designed with aluminum welding in mind, are more forgiving and have much bigger sweet spot settings.
Anyone who has done much mig welding with a spool gun knows that even one small movement of the wire speed knob on the spool can make all the difference.
10. Temperature of metal.
when mig welding steel of any thickness greater than say 3/16" , it takes 3 or 4 beads done back to back to get the metal hot enough that the puddle acts very differently. The steel could be cold or hot and it welds similar.
Just a slight preheat of aluminum makes a huge difference in the way it welds. The first bead could be too cold, and the second bead, too hot..conductivity is the reason. Aluminum is much more conductive than steel.
If you are thinking this is an article trying to discourage you from mig welding aluminum, you are wrong. I am just trying to be real and lay it out there the way I see it. No need to sugar coat it. Anyone can buy a mig welder with a spool gun regardless of skill level ...and thats a recipe for discouragement without the proper heads up .

Arc Welding Project

Why did this simple job turn into an arc welding project?
Normally, Mig welding is the choice for fabrication jobs like this one.
It was a simple stand for a bender. A stick of 3 1/2" tubing with a flange plate welded on one end and a mounting base plate welded to the other...simple as they come.
So why Stick weld, when mig welding would be faster and easier?
Well...
My buddy tack welded one of the flanges with a tig welder and the tacks were so jacked up, so oxidized, so ugly, it was either cut the thing off, grind all the weld off and start over....
..or just whip out the stick rods and weld right over all the junk and call it good.
Sometimes, good enough really is good enough.
A 7018 stick rod burned in nice and hot will definitely hold till the cows come home on a stand for a tubing bender. I dont care if a 6 foot cheater bar is used for bending, these welds aint gonna give.
So instead of all that extra work for nothing, I decided to Stick weld this job.
Not only would the 7018 Stick rods burn thru all the crud better...but My pal didnt even have a mig welder hooked up at his shop...I would have had to haul one for a 30 minute job. ( actually, because I filmed it, it was more like 2 hours)
Anyway, The Everlast Powerpro 256 tig, stick, plasma combo welder was already there, hooked up and ready to rumble. I keep it set up for tig welding at my machinist friends shop. But swapping it over for stick welding only takes a few seconds...so thats what I did.
All I had to do was unhook the tig torch and plug in the stick leads.
The square tubing my friend wanted to use for this arc welding project was 3 1/2" x 3/16" wall and the flange mounting plates were 1/4" thick.
In this arc welding project video, I show how to center the tubing, tack weld, get it square, along with some arc welding tips for how to weld it without a bunch of stops and starts ...except on the corners.
I also show a tip for another way to prop for arc welding using a tig finger.
One thing every welder needs to know is how much tack welds draw...how much they will pull a piece out of square. Knowing how much the tack welds pull lets you pre position a piece to allow for that and lets you get things square and plumb without cutting tacks loose and reworking. Thats what you wind up doing if you dont allow for the tack welds drawing.
I can tolerate certain things not being perfect but things being out of square and out of plumb...drives me to distraction...I hate it.

Arc Force and Arc Control

What is the Arc Force / ARc control knob and what does it do?
The arc force/control lets you adjust whether you have a soft buttery arc or a digging arc.
Arc voltage drops as the arc gets tighter.
When you set the arc force knob high , the machine makes the arc dig more by sensing a drop in voltage when the rod is about to stick...an arc welding machine with arc force control compensates when the rod is about to stick by increasing the arc voltage. You can literally jam the rod in as tight as you like without sticking if you have it hot enough with the arc control set high.
Setting the arc force knob low, gives a soft buttery arc.If you were hardfacing backhoe bucket teeth, a soft arc might come in handy to prevent that hardface rod from diluting too much with the softer base metal.
Who wants to pay an arm and a leg for hardface rod only to have it turn out soft because too much base metal was melted?
Today , for this arc welding project, I set the arc force to dig because the 7018 rods I was using were old and had been sitting out in the air for like 2 years. I knew they would have a tendency to stick if I didnt set the machine for a digging arc.

Aluminum Welding Training

Aluminum Welding - Tig welding Aluminum. That is the way. If Yoda was a welding instructor he would have all his Jedi masters tig welding aluminum to make them strong in the force.
This is starting to sound like a line of BS so I better get to the point. What I am saying is that aluminum welding will make you a better welder of all metals....not just aluminum.
Why?
here are just a few reasons:
With Aluminum welding, You have to feed more rod...your rod feeder hand will have to get better and faster and that will help on all metals.
Conductivity...aluminum will make you pay more attention to your foot pedal amperage control because the heat changes a lot more than stainless or carbon steel
Seat Time/ Arc Time...practice like I outline here and you get lots more seat time.... you spend your time welding and not cleaning and wire brushing.
Getting a piece of aluminum about 1/8” thick and stacking beads on it is the best tig welding practice there is.
That’s a pretty strong statement but here is why its true:
Aluminum cools quickly and doesn’t form a grey oxide film like carbon steel does so you can stack beads , one on top of the other and the puddle will flow the same bead after bead…well , almost.
Aluminum conducts heat rapidly so you have to get used to working the foot pedal remote amperage. You cant get lazy and just leave your amperage in one place like you can with steel. Aluminum exaggerates everything that can go wrong with steel.
For example, too much arc length, too much torch angle, not enough amperage, too much amperage….all will cause problems and make you think more about how to fix your technique.
Aluminum has a big attraction for your tungsten electrode and wants to jump on it at every opportunity…(at least it seems that way.)
When ..not if, but when your electrode gets crapped up with aluminum, stop and clean it off with a sander. You can get away with a tiny bit of contamination when you are tig welding steel. Not so with tig welding aluminum...unless you like welding aluminum inside a big cloud of black soot.
With just one scrap piece of aluminum sheet, you can stack bead after bead practicing spacing your ripples, keeping your bead width consistent, welding fast, slow, medium.
The piece I welded for this page was 4” x 8” x .125” thick 3003 aluminum. It does not matter what grade you use… . whatever you can get your hands on will do.
I recommend welding a bead all around the edges first. That is really good practice controlling amperage…too much amperage and you roll the edge off and the bead gets fat and ropey. Too little amperage and you don’t even melt the rod without it just balling up.
Once you get an edge weld all around, practice just running beads and stacking them evenly. Not just running random beads, but practice with purpose. Purposefully stack beads as straight as you can.
Practice Welding right handed, left handed, weld fast , weld slow, add rod every 1/8”, try adding rod every 1/16” too.
Pay attention to the difference.
Which ripple spacing do you like better? Sometimes its just a matter of preference. Do you like the stack of dimes look? Or do you like tightly spaced ripples better?
Practice stacking beads diagonally too. When you are building up a big lug on an aluminum transmission case, you need to vary the direction of beads to spread the shrinkage stresses. That can actually help prevent distortion and cracking.
The time to get good at stacking beads is on a scrap piece of aluminum. Not on the actual job.

Tig Welding Pipe

A Tig Welding Certification test on pipe is usually done on a 45 degree angle. Also called the Arkansas Bellhole, but technically known as the 6G position.
Welding codes for administering tig welding certification tests are all very similar in that they all recognize a 6G position test as being the most difficult so they figure if a welder can change body position and hand position to adapt to the different challenge that each side of the pipe gives, then the welder can surely weld all other positions.
"Walking the cup" is a technique often used for tig welding pipe. what it means is that the tig cup is rested on the weld and wiggled or walked like you would walk a 55 gal drum on the floor...along the joint to make the weld.
Anyway, walking the cup is fine for certain situations but not for all. For example, Have you ever taken a tig welding certification test on 1/2" pipe?
Thats pretty small stuff to walk a cup on. ... Its very easy to slip right off.
I would much rather be able to shift gears and freehand when the situation calls for it than to be a one trick pony cup walker....wouldnt you?
When I first learned tig welding, it was on 2" pipe and I freehanded and rested my pinky on the pipe to steady my hand.
Later, I learned to walk the cup on bigger pipe.
But I do remember taking a welding test in a shop where the welding test inspectors were dead set against "cup walkers". Literally every welder who walked the cup that day, walked away without a job...
When in Rome, you are supposed to do as the Romans do...So when you roll up on a job where no one walks the cup, you might need to do as they do just to get the job.
Anyway, I am glad I was able to freehand because, by being allowed to hand around, I learned a new tig welding technique for putting in a root.
What is that technique for tigging in a root pass? Its in the video. But essentially, its just moving the tungsten forward and back instead of wiggling it sideways like you do on a root when you walk the cup.
Moving the electrode forward and back just is not possible if you are walking the cup. But its easy if you use a tig finger heat shield and rest your knuckles on the pipe. You can go sideways, forward and back, or as narrow or wide as you see fit...thats the benefit of not always walking the cup for tig welding certification tests or any other tig pipe joint.