Welding Tips and Tricks

Hi all!

All new to the forum, so I should warn you that my native language is Norwegian (which potentially could cause misspellings and unintentional poor orthography).

Now, to the point:
I'm a happy amateur welder. I've welded MIG for quite a few years and feel I've got to grips on that, but after reading and watching Jody's tutorials I realized that a TIG could (potentially) solve all my precision welding problems.

Beeing an amateur, I can't justify buying a high end AC/DC TIG machine (ESAB, Kemppi, Lincoln, Miller, etc), as they are excruciatingly expensive here in Norway (as an example the smallest Kemppi AC/DC TIG (160A) costs USD 6700, and the others are not much cheaper).

So I bought a cheap Chinese model. According to many reviews (here is one comment) it's supposed to be one of the better ones. It's a yellow Rilon, and as far as I can tell it delivers as promised.
Compared to the Everlast Jody has been demonstrating, it lacks a few settings. Among other things, I can't control the AC freq. To spare you all the details, I've included a picture of the front:

Forgive the long introduction, but I see you always ask "what type of machine are you using, what are your settings..." etc. So now you know my machine.

My first project has been putting together a welding trolley for the machine.
I've tried to weld different grades and thicknesses of steel with success, so I thought I'd plunge into the deep end by making my trolley in aluminum. According to Jody, aluminum is the most challenging material for beginners. (I also wanted a light weight trolley).

Then finally, my problem description:
I'm welding square aluminum tubing 3/16" thick. I use pure Argon gas set at approx 15 cfh. I use a remote pedal for amp control, and I've set the max amp to 120.

My main problem is that my problem is not consistent!
Some of the welds looks text-book, but most of them look like "Fido's behind" (to borrow Jody's description).

My main problem is getting the weld pool/puddle going. If I get a nice shiny puddle, then no problemo. I can feed in rod and get a nice stack.
However, if I fail to get the base metal up to temperature, the tip of my rod just melts off in droplets floating on top of the fuse line.

When I have problems getting the base material to form a liquid puddle, it looks like there's some type of "skin" on top of it. The "skin" looks like the somewhat warped surface you see on each side of the "stack of dimes" on a successful bead of stacked diamonds.
In other words, it's not liquid but looks like a thin solid layer floating on top of a thin liquid layer).
Through my own reasoning I figured this must be an oxidized layer of aluminum floating on top of the puddle. If I increase amperage, I just end up burning a hole in the tube (I've set balance to 65%).
As long as I have this oxidized layer, I'm unable to get the filler rod to blend with the puddle, and it floats helplessly as restless droplets on top of the base material.
Another problem that occurs when this happens, is that the droplets seem to rise towards the tungsten rod on reverse polarity. In other words, the droplet "jumps/stretches" up from the base material and clings to the electrode immediately after it's left the rod. That leaves me with a contaminated electrode, and I have to stop and re-grind it.

My main problem is that the problem is not consistent.
I can weld one or two sides with text-book beads, and then BAM the base metal refuses to form a shiny puddle.
I've thoroughly cleaned the surfaces (stainless steel brush), try to hold the torch close to 90 degrees (+/- 10 degrees), keep the electrode at a distance of approximately 1/8", etc. But when I get the "skin", I'm at a loss.
Sometimes I've been successful in "braking through" by stepping on the pedal immediately after the arc starts to "shock liquify" the base metal, but just as often this just leads to a burn through or a deep "dimple" at the start point. Other times, I simply can't get rid of it.
Needless to say, the moment the electrode gets contaminated or the work piece suffers from rod splatter, soot or whatever, I immediately stop and clean the work surfaces.
The problem is particularly pronounced when I try to weld the T-joint between the square tubing. I've so far been unsuccessful in creating a liquid puddle to dip the rod in. All I end up doing is melting the tube end and/or burning a whole into the adjacent side.
So...
does anybody have any tips or explanations to what's happening?

sros wrote:Hi all!

All new to the forum, so I should warn you that my native language is Norwegian (which potentially could cause misspellings and unintentional poor orthography).

English is a second language to you?

I don't believe it. You write English far better than most speak it.

Ottos right about the english!

But for you question, the ac current should be what breaks through the skin, not the heat, so try turning that on up first.

Secondly, fillet welds for me always seem to take more heat, I mean think about it, theree is alot more surface area, and potential for contamination, ect. But if you cant turn up your heat, can you preheat the workpeice? I dont know what the machines duty cycle is, but you could try to pre-heat the welding area with the tig torch, running up and down the peice for a little while.

I used to have that exact same thimg happen to me all the time, and mostly for two reasons: The aluminium was dirty, or i had'nt yet fully heated the work area(be patient becuase it can take awhile)


Best of luck in norway,

-Rick

Otto Nobedder wrote: English is a second language to you?

I don't believe it. You write English far better than most speak it.

Thank you, I'll take that as a compliment.
I use the dictionary vigorously (and also spent two years in the Texas as a student many years ago).

rickbreeezy wrote:
But for you question, the ac current should be what breaks through the skin, not the heat, so try turning that on up first.

Secondly, fillet welds for me always seem to take more heat, I mean think about it, theree is alot more surface area, and potential for contamination, ect. But if you cant turn up your heat, can you preheat the workpeice? I dont know what the machines duty cycle is, but you could try to pre-heat the welding area with the tig torch, running up and down the peice for a little while.

I used to have that exact same thimg happen to me all the time, and mostly for two reasons: The aluminium was dirty, or i had'nt yet fully heated the work area(be patient becuase it can take awhile)

I agree with your contamination concerns. Even the slightest bit of dirt and grease, or worse, a pre existing oxidized layer will ruin all attempts of getting a clean puddle. I experimented with some pieces of scrap metal, just to see how little it would take to ruin the weld.
Hence, I clean the work area thoroughly to avoid those kinds of problems.

What do you suggest I do with the AC? I can't adjust the AC frequency so I'm at a loss there. I guess I can adjust the balance to get more cleaning action. I've had it at 65% so far, but guess I could turn it more towards 30-40%. Unfortunately that's gonna make me more prone to tungsten meltdown so I'll have to ease up on the amps.

I'm welding in a cold garage, so your pre-heating tip might be well worth a try. It didn't occur to me to use the TIG torch to pre-heat the metal.
I will give that a try and report back.

That made a big difference.
I was finally able to make a successful T-joint. Encouraged by my success, I went and bought a cheap gas torch to make pre-heating easier.
I'm still not proficient by a long shot, though some of the beads looks fairly OK. The rest are more "functional" than eye candy, but at least I didn't burn through this time.

This probably doesn't apply, but I encountered yesterday and thought I'd mention it.

A fellow was making a simple repair on 1/4" Al, and was having trouble. He was using a Miller Syncrowave 250DX. I finally noticed, while he had the machine set on AC, He'd left it on "HF Start", instead of switching to "constant high-frequency". A simple oversight.

It wouldn't hurt to double-check your settings.

Since your problem occurs on fillets, but not flat welds, gas flow could be an issue. What type of flowmeter are you using? Do you have a tapered tube (with a floating ball), or just a gauge? If it's a gauge, it might not be correct, and you might try experimenting with less gas flow.

Glad to hear the pre-heating helped.

Steve

Unfortunately, I have little control over AC frequency on this model.
It has built-in HF start, but apart from that it doesn't seem to have any controls for AC manipulation (if you zoom in on the picture I attached in my first post, you can see the various controls available to me).
The only knob I can find for frequency modulation, is the pulse frequency knob (which only controls the amperage shift and not AC frequency as far as I know).

You're right about the flowmeter. I have a twin gauge (one shows bottle pressure and the other flow). I did actually suspect it might be off, just like you mention. So I reduced gas flow after hearing what I perceived as excessive "hissing" and cooling of the work piece.
That did actually help.

I mentioned the flowmeter because another poster was having a similar (but worse) problem. Simply introducing the rod into the gas flow drew air into the puddle and immediately oxidized the puddle. He tried another flowmeter, and voila, problem solved. In calm air, it takes very little gas flow to properly shield your weld. I suggest doing fillets on scrap while dialing down gas flow. When you find the minimum, mark it on the lens of the gauge, and stay a few CFH above this line.

I'm glad your cart project is working out well. ("Trolley" is common in British-English. "cart" is more common in American-English, so I guess you can tell which side of the pond I'm on. )

Steve

I had to check in the dictionary, and you're quite right. Among various interpretations of the word "cart", one describes it as "a shallow open container on wheels that may be pushed or pulled by hand".
If I look up "trolley", it contains a similar description but with (Brit-eng) in front of it. Beeing geographically closer to Britain, I guess I'm subconsciously influenced.
In Norwegian it's called "tralle" (welding cart = sveisetralle), so I guess that's why "trolley" was the first word that came to mind.

Trolley/cart finished this evening, and it came out all right!
I guess it won't win any prices (neither for design nor welds), but it's functional and sturdy and that's what I needed. I haven't welded on the arced handle bar in front yet, as I need to get hold of some bent pipe first.
I guess I will "pimp it up" later, by adding some hooks on the side or in front to hang cables and other utilities on, and I'll probably add in a drawer as well.

Ståle

sros wrote:...In Norwegian it's called "tralle" (welding cart = sveisetralle), so I guess that's why "trolley" was the first word that came to mind.

Ståle

Sveisetralle.jpg

Can you give me a reasonable phonetic spelling to pronounce that (sveisetralle)? I love to learn new words! I'm guessing this one sounds a lot like it's English spelling.

Excellent work on the "trolley", by the way. Is the drawing your work?

Steve

Otto Nobedder wrote:
Can you give me a reasonable phonetic spelling to pronounce that (sveisetralle)? I love to learn new words! I'm guessing this one sounds a lot like it's English spelling.

That's almost as hard as TIG-welding aluminum for the first time!

I don't know how to use the phonetic alphabet, but I'll improvise.
Here goes:
The first diphthong "ei" in "sveis" is pronounced like "ay" in "way". Actually like "s-way-s" but with a distinct "v"-sound instead of "w". The subsequent "e" is pronounced like the first "e" in "estate".
The third syllable (the "a" in "tralle") is pronounced like the first "a" in "apart" (more of a "ah" sound than the a in "awe" if you understand). These two "e"-s (sveisetralle) are pronounced the same.

You can also see we use contractions as the main rule in Norwegian. I.e. "sveisetralle" instead of "sveise tralle". So with an identical vocabulary we would write "weldingcart" instead of "welding cart".

-----

I made the drawing myself in "SketchUp", Googles free CAD software. Quite easy to learn (at least the basics of it). I just measured the length and width of the machine, then the height I thought would be a comfortable work height, and finally added some space in the back for the gas bottle.
Sketchup automatically displays all the measurements when you click the individual components with the measuring tool. You can display them in inches/feet or in the metric system as we use over here.

Ståle

Nice work on the drawings! I have a similar freeware cad program, but I have yet to experiment with it.

Thanks for the language lesson, too. I believe I understood it completely.

I had it close in my head, but, in the English custom, I wasn't pronouncing the second "e".

Steve

I know, that's the most common mistake english speaking people do when they try to learn Norwegian. I guess there are no words in English that ends with a pronounced 'e', so it feels very "unnatural" for you to actively pronounce it. In Norwegian, all (male) nouns ends with "en" (definite form), "er" (plural), or "ene" (definite plural).

In other words:

Tralle - cart
Trallen - the cart
Traller - carts (carts plural indefinite form)
Trallene - the carts (carts plural definite form)

Another noun like "bil" (means car) that doesn't have an "e"-ending in infinitive form, gets the same ending in definite and plural - bilen, biler, bilene.

-----

Well, enough grammar.
Like I said earlier, my lack of skills made me burn through the square tubing at two T-joints in the beginning (1). Are there any technique for filling the holes (that I have a reasonable chance of mastering) or is my best chance just to weld a new plate on top of it? That will just be an ordinary lap-joint with less chance of me burning through the tubing again.

I thought of splitting a piece of the square tubing diagonally (2) and welding the pieces on (3) after grinding down the damaged areas like shown below.
If I go for that solution, will it structurally be strong enough if I only weld where I've marked in blue (3), or should I weld it on the sides as well? (profile thickness is approx 1/8")

In your suggested repair, you will get more ultimate strength welding the sides INSTEAD of the areas you've indicated. Welding the sides gives you strength in tension. Welding across the web introduces two HAZs, and without welding the sides allows a lot of flex in the joint.

Repairing the holes isn't all that difficult. Are you able to back-purge the weld? Of course, make sure the gas has an escape path other than the holes. Maintain a lower current than you originally welded with, and work the torch in a tight circle inside the circumference of the hole. As a puddle develops (keep it pretty cool) start introducing rod on one side of the hole. Keep working in a circle, backing off on the heat as you go. Once you see the hole close, give it a good burst of heat while feeding in a bit more rod, then shut it off. For your sveisetralle, you will not need a perfect repair, but it will be good practice.

Again, I was fascinated with the language lesson.
If i follow,

Bil = car
Bilen = the car
Biler = cars
Bilene = the cars

Steve

I don't think I'm able back purge the weld, only have one gas bottle and that's connected to the TIG-machine.
If I could though, I think I would have problems with the gas escape path as the tube is closed. I would have to make two new holes (one to introduce the gas, and one for it to escape through) and that would be kind of counter productive I guess.

I'll weld the patch metal on as you suggested instead.

Otto Nobedder wrote:
Again, I was fascinated with the language lesson.
If i follow,

Bil = car
Bilen = the car
Biler = cars
Bilene = the cars

Steve

Spot on!

----

Takk for all hjelp så langt!
Mange gode og nyttige aluminiumstips for en novise innen TIG sveising.
Nå vet jeg hvor jeg kan finne hjelp når fremtidige problemer oppstår.

(which translates to:)
Thanks for all the help so far!
Many good and useful aluminum tips for a TIG welding noob.
Now I know where to find help when future problems arise.

Ståle

Ståle,

Here's how similar our language roots are:

"Takk for all hjelp så langt!
Mange gode og nyttige aluminiumstips for en novise innen TIG sveising.
Nå vet jeg hvor jeg kan finne hjelp når fremtidige problemer oppstår."

I understood 60% or so of that before I read the translation.

Steve

Yes we have common language roots in the Indo-European language that was later divided into North and West Germanic (East Germanic equals Gothic which is a dead branch).
Our language mixed again later when Vikings conquered and colonized England in the 8th and 9th centuries.

All place names ending in -thorp (torp), -ton (tun), -by (by) and -ham (from homestead which again comes from "heimstad") are of Scandinavian origin.
Even New York has Viking roots. It's named after York in England which is a simplification of Jorvik, the city's original Viking name.

I've never been to New Jorvik.

I've been to a ton of places that end in "ton"

I skimmed through your original post and some of the responses. Aluminum is difficult to learn but once you get some critical parts together, it welds like a dream and is very fun. Here are some set up numbers for your machine and process for weld preparation.

Machine Set up: these are basic parameters for your machine set up.

1. HELIUM.... I can not stress this enough. When welding Aluminum, ALWAYS USE HELIUM! I weld in the aerospace industry and every single welder I know flows helium in the process of welding Aluminum. Pick up a bottle of mix and it will make life much easier. It makes a huge difference. In aerospace welding of aluminum we use something different than a Argon/Helium pre mixed bottle. We actually mix a bottle of Argon and a separate bottle of Helium manually with multiple flow meters and Y valves, but there is way too much variables in that set up at this time.

2. Do not use a diffused cup on your Tig torch. Use a standard normal collet body with a cup size 5 or 6. Min. 3/32 tungsten, but I would use 1/8 on material with .188 wall thickness.

3. With material that thick, set your balance to a min. of 75%. You will have plenty of cleaning action on the EP side of the AC wave. The higher the balance number the more penetration and less cleaning you will have during the AC wave.

4. Don't worry about AC frequency. The least of your worries. Frequency becomes more important on very thin material and when welding joints with less than a 90 degree angle between two parent materials.

5. Turn the amps up. Good rule of thumb is 1 amp for every .001 of material being welded. This is rough but with Aluminum it will give you the "poop" you will need.

6. Don't worry about back purging. Unless you are x-raying the part, it's not needed.

7. Take your time. Let 'er get hot!!!!!

8. Min of 3/32 filler. Use 4043 filler since no rod spec is called out. This is fun welding.

Material prep:

1. Fitment. Make sure your joints are tight.

2. Clean. MAKE SURE TO CLEAN THE OUTSIDE AND INSIDE OF THE JOINT WITH ACETONE! Safety glasses and rubber gloves are a good idea.

3. Pre heat. Heat up the material that is to be welded. It doesn't need to be nuclear hot but say around 120-130 degrees is good for starters. This will also remove any moisture on the material. Water is very bad with Aluminum or any type of welding for that matter. Especially with Aluminum.

Start slow and let the heat along with the Helium mix do the work.

DC Aluminum welding but that is a whole different topic. Cheers and good luck.

cjfabs,

You are aware that Ståle has solved his original problem and completed his project?

You and I have ready access to helium. For most hobbyists, the cost is prohibitive even for a mix.

The only reason for a plain collet-body is to conserve gas, and this only applies in a dead-still environment (not the average hobbyist garage). I will argue for a gas lens every time, and only use a collet body when it is the only way to reach an extremely restricted weld.

You must realize the majority of the people here do not have access to the high-end equipment and facilities you are accustomed to.

I've welded cryogenic (LH2) vacuum-jacketed process piping using techniques you would consider primitive (I don't even use a remote pedal. I use a thumb control as an on/off switch.), and have never had a failure, or even a leak.

You should tailor your replies to suit the abilities and equipment of those asking the questions.


Steve

My reply was welding Aluminum 101. Not necessarily aimed at Stale's question. Just thought I would throw some info out. Helium is not that expensive and buying a dedicated Argon/Helium mix bottle is not needed. Just easier. And nobody welds Aluminum wih a diffused lens. Everybody that welds for a living uses the cheap ole regular collet body with a small exit diameter cup. They are cheap too. Stainless, Titanium and various alloys are a different story. Champagne cups and flowing 35-50 cfm as you know. I was trying to help and hoped maybe Stale would come back across my post and it would help him on future projects. Nothing I stated was over the top for beginners or garage/hobby types. Cheers

Balloon grade Helium works great and is not expensive. Don't waste your money on the more expensive stuff.

Cjfabs wrote:Balloon grade Helium works great and is not expensive. Don't waste your money on the more expensive stuff.

True. This occurred to me as well. I find He is less about cost than quantity. A "Balloon bottle" from "Party City" holds what? about 20 cf? For $20? This is probably a good deal for the hobbyist using 80/20.

I apologize for any harsh tone in my reply. I was (to my embarrassment) allowing a discussion on another forum to influence my emotions. And, I know better. (Or, at least, I otto nobedder .)

Steve

Cjfabs wrote:... Everybody that welds for a living uses the cheap ole regular collet body...

I have to disagree with this. I suppose it might matter just HOW you make your living, but I have always used a gas lens for everything I do, unless left without a choice based on access to the weld.

I have worked outside in blowing snow. I've welded in pouring rain. I'm currently working in a cushy shop job. I use a gas lens every time, and everyone I know who is serious about their trade does as well.

Steve