Don't get me wrong, if I thought using several different types of tungsten would help my welding, I would do it. But if one single type will do, then I don&#;t want different kinds and colors of tungsten electrodes in my toolbox.
If you are like me, sometimes without thinking, I grind off the color code so I can have 2 sharp ends. If I have several different types of tungsten electrodes in my toolbox, I can't easily tell them apart without the color code.
Back when I worked in aerospace, the Safety Department required me to find a substitute for 2% thoriated electrodes because of all the negative news about thoriated electrodes being radioactive. So I did some pretty extensive testing to determine the best all-around tungsten electrode for both DC and AC that would work on all metals, steels, superalloys, titanium, aluminum, magnesium, etc.
For me, the three criteria that were the most important for TIG welding anything from razor blade thickness on DC, to thick, aluminum and magnesium castings on AC are:
1. Low amp crisp DC starts and restarts
2. Stability at 200 amps on AC with a 3/32&#; tungsten.
3. Works well with both transformer AND inverter TIG welding machines.
If a tungsten electrode fits these 3 criteria, then its a good choice for an all purpose tungsten electrode.
So therefore, I tested:
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E3
Trimix Blends
Layzr
2% Ceriated,
2% Thoriated
1.5% Lanthanated
2% Lanthanated
And several others
On DC, there were only very minor differences &#; they all worked pretty well. But on AC, the 2% lanthanated was much more stable up to 200 amps than the rest of them were.
The 2% lanthanated electrodes worked well on low 1 amp DC arc starts, and also worked better than the others on AC, whether using a transformer welder or inverter.
So that is why I recommend using 2% lanthanated if you are looking to settle on one, single best, all-around tungsten electrode.
I don't want to give the wrong impression that 2% lanthanated is the best for every single application....because there is no one single tungsten type that is best for every specific application.
You would need several different types of tungsten to get the absolute best for each application and sometimes the difference would be so small, it would be hard to tell.
With all the aerospace welding tests I have administered, all the job shop work I have done over the last 10 or 11 years, and all the YouTube videos I have made, I have only used 2% lanthanated electrodes for everything since around .
And that sure made things simpler for me!
So if you are looking for the best all around tungsten electrode for TIG welding all metals, I hope this article helps simplify things for you.
Tungsten welding electrodes cannot be destroyed during the welding process as they aren't dissolved into the weld pool. Extraordinary consideration should not allow the electrode to contact the welding pool to stay away from weld pollution. This would be alluded to as tungsten consideration and may bring about weld disappointment. Terminals will regularly contain little amounts of metallic oxides, which can offer the accompanying advantages:
Assist in bend beginning.
Improve current conveying limit of the electrode.
Reduce the danger of weld pollution.
Increase electrode life.
Increase weld security.
These TIG electrodes are unalloyed, 'rare' tungsten with a 99.5% tungsten least and are generally minimal. They give great curve strength when utilizing AC, with either adjusted wave or unequal wave and consistent high-recurrence adjustment.
Pure tungsten electrodes or Rare tungsten electrodes are liked for AC sine wave welding of aluminum and magnesium since they furnish great bend dependability with both argon and helium protecting gas. The rare tungsten terminal effectively frames a balled end yet tends to spit at higher flows, and this ought to be viewed when making basic welds.
These TIG electrodes are alloyed with about 2% ceria, a non-radioactive material, and the most bountiful uncommon earth components. The expansion of this little level of cerium oxide expands the electron outflow characteristics of the electrode, which gives them a superior beginning trademark and a higher current conveying limit with no spitting.
These are universally handy terminals that will work effectively with AC or DC electrode negative. Contrasted and rare tungsten, the ceriated tungsten electrodes accommodate more prominent bend soundness. They have phenomenal curve beginning properties at low current. Whenever utilized on higher current applications, the cerium oxide might be concentrated to the unreasonably hot tip of the terminal.
This condition and oxide change will eliminate the advantages of the cerium. The non-radioactive cerium oxide has marginally unique electrical properties when contrasted with the thoriated tungsten terminals. The cerium electrodes function admirably with the Advanced Squarewave power sources and should be ground to an altered point.
These TIG electrodes are alloyed with non-radioactive lanthanum oxide, frequently alluded to as lanthanum, one of the uncommon earth components. These terminals have incredible bend beginning, low disintegration rate, curve dependability, and fantastic re-start attributes.
Expanding 1 &#; 2% lanthana expands the greatest current conveying limit by around half for a given size terminal utilizing rotating current contrasted with rare tungsten. The higher the level of lanthana, the more costly the terminal. Since lanthana terminals can work at marginally unique bend voltages than thoriated or ceriated tungsten electrodes, these slight changes might require changing welding boundaries and methods.
The lanthana is scattered uniformly all through the whole length of the electrode, and it keeps up with a honed point well, which is a benefit for welding steel and treated steel on DC or the AC from Advanced Squarewave power sources. Accordingly, the 2% lanthanated tungsten electrodes function admirably on AC or DC electrode negative with a sharp end, or they can be balled for use with AC sine wave power sources.
Thoriated electrodes, both 1 and 2% are ordinarily utilized electrodes since they were quick to show better bend execution over rare tungsten for DC TIG welding. Be that as it may, thoria is a low-level radioactive material; along with these lines, fumes, granulating residue, and removal of thorium raise wellbeing, security, and ecological concerns.
The moderately limited quantity present has not been found to address a wellbeing peril. Be that as it may, if welding will be done inbound spaces for delayed timeframes, or then again if terminal crushing residue may be ingested, uncommon precautionary measures ought to be taken concerning appropriate ventilation. The welder ought to counsel an educated security workforce and find suitable ways to avoid the thoria.
These terminals are generally liked for direct current applications. In numerous DC applications, the terminal is ground to a shape or pointed. The 2% thoriated tungsten electrodes will hold the ideal shape in those applications where the rare tungsten would liquefy back and structure the ball end. The thoria content in the electrode is liable for expanding the existence of this sort over the rare tungsten.
This TIG tungsten is alloyed with zirconium oxide (zirconia). It is liked for AC TIG welding when the best work is vital and where even the littlest measures of weld pool pollution can't go on without serious consequences. This is refined because the zirconium alloyed tungsten delivers an amazingly steady circular segment that opposes tungsten spitting in the curve.
The current conveying ability is equivalent to or somewhat more prominent than an equivalent measured cerium, lanthana, or thorium alloy electrode. Zirconium electrodes are regularly utilized uniquely for AC welding with a balled end.
The tungsten electrodes arrive in an assortment of breadths, and you would choose the proper distance across for the current to be utilized and type for the cycle mode. To truly distinguish the tungsten type, the end is plunged with a shading.
When it comes to TIG welding, there&#;s a lot to know from what TIG welding machine to use which we have covered in a previous guide to learning about creating smooth weld seams, clean welding joints and using high-quality materials.
It&#;s important to remember that choosing the right tungsten electrode for TIG welding is equally as important as getting the right contact tip for MIG welding.
At Engweld we offer a range of TIG welding electrodes and each is colour coded to identify their distinct characteristics. We&#;re here to show you what each electrode is best suited for and give you a guide to finding the right electrode.
While tungsten is the main component of TIG welding electrodes, apart from pure tungsten electrodes, other varieties are enriched with further elements, which is known as doping, or tungsten doping.
How do I find the right one for my welding?
Similar to choosing the right TIG welder, this depends largely on the welding task and factors like whether you want to weld direct current or alternating current as not every type of electrode is suitable for alternating current, which is used for aluminum welding. Other factors like the welding task and the material to be welded will have an affect on whether pure tungsten electrodes are used or those with oxidic additives like zirconium oxide (ZrO2), lanthanum oxide (La2O3), cerium oxide (CeO2) or thorium oxide (ThO2) need to be used as they all have different properties.
Zirconium oxide keeps the evaporation lower and enables a more stable arc compared to pure tungsten electrodes.
Cerium oxide gives a tungsten electrode very good ignition and reignition properties.
Lanthanum oxide has good ignition properties and gives the electrodes a longer service life.
Thorium oxide creates a very stable arc, however it is radioactive which means it is very harmful to health. When thorium smoke or dust is inhaled, it can be deposited in the lungs and lead to internal radiation exposure.As a result it has been banned as an additive to tungsten electrodes in many countries.
A pure tungsten electrode (WP green) enables a very steady arc while oxide-containing electrodes are easier to ignite, have a high current carrying capacity and a longer service life.
The BINZEL E3® is a tungsten electrode which uses a mixture of rare earth oxides as doping elements, which makes it suitable for direct current and alternating current welding and also for use with almost every metal. Thanks to its excellent ignition properties, it is also often used for automated processes. The electrode temperature remains consistently low, which increases the current-carrying capacity and increases the service life of the electrode when compared to thoriated electrodes which can only be used in exceptional cases due to their highly harmful effects.
This tungsten electrode uses the doping element lanthanum oxide and can be used for direct current and alternating current welding. WLa is mainly used for welding aluminium, titanium, unalloyed and high-alloy steels, copper and magnesium alloys. The golden version of this tungsten electrode is also used in micro-plasma welding.
Due to using cerium oxide as the component of this TIG welding electrode, it is more resilient than a pure tungsten electrode but less than the E3® and lanthanum electrodes. This type of electrode is most commonly used in the medium and lower current range for welding high-alloy and unalloyed steels as well as copper, nickel, aluminum, titanium and magnesium alloys. These electrodes are also suitable for alternating current welding as well as for direct current welding, but not as well as E3® electrodes.
This electrode is made of pure tungsten and is used only for AC welding. Tungsten also has high resistance and very high corrosion resistance and its melting point of 3,422 °C is ideally high for welding using alternating current. This is also the ideal electrode for welding aluminum alloys
The addition of zirconium oxide means that the risk of contaminating the fusion is very low. This tungsten electrode was specially developed for welding with alternating current in nuclear systems. Zirconium oxide ensures a very stable spherical cap in AC welding, but it ignites very modestly in DC welding.
Top Tip: The WZr and the pure tungsten electrode should only be used with old single-phase TIG power sources.
Why you should avoid thorium electrodes
As mentioned earlier, TIG welding electrodes that use thorium oxide as a doping element are extremely harmful to health due to their radioactive properties. As a result they are now banned in several countries and the German statutory accident insurance »DGUV« information 208-049 refers to the fact that thorium oxide-containing tungsten electrodes &#;may only be used for product-specific requirements (compelling technical reasons)&#;. When they are used in this instance, the provisions of the Radiation Protection Ordinance must be observed.
The ideal tungsten electrode for any welding task is E3® (purple). This electrode is long-lasting and guarantees the best results, as well as being better for the environment. When tungsten grinders are used, the residual dust and leftover pieces are not classed as hazardous waste, and do not require any special protective measures for transport and storage as E3® welding electrodes are free of radioactive components. These electrodes also comply with the EN ISO standard.
Suitable for almost all welding tasks
Electrode tip which is cooler running than Thoriated
Superior repeatable ignition characteristics
High arc stability
Little deformation of the electrode tip
Low burn-off
High current carrying capacity
Still aren&#;t sure which tungsten electrode is right for you?
A safe choice for all types of welding is the E3, however if you want to find out other tungsten element options, view our full product range for more info or get in touch with our team of technical specialists who will be happy to help find the right Engweld product for you!
I decided to write up a summary / guide to some of the topics specific to welding bicycle frames together. I got started, and then this ended up being a beast of a post. Hopefully this is useful to some of you! I know I didn&#;t cover every possible thing here, but I can always add more. I&#;ve been in the welding industry my whole professional career, so I&#;d like to think I&#;m somewhere on the down-slope of the dunning-kruger curve (maybe that means I&#;m actually on the up-slope?)
Anyways, Here goes.
This guide is intended to give an overview of welding bicycle frames using the GTAW (Tig) process. It assumes the reader already has a basic understanding and some experience with the process, since welding thin-wall tubing is most certainly an advanced niche of Tig welding.
If you&#;ve never touched a Tig welder before, this may not be the best place to start, but can certainly act as a reference or overview of some of the tools & techniques.
If Tig welding was mountain biking, welding a bicycle frame is dropping into a black diamond trail.
I will note in this guide I typically just say &#;&#; as a general term for bicycle tubing. Some tube sets will differ in their exact composition, but for the scope of this guide we can group them into somewhat safely. High-spec tube sets may differ. Some dropouts, headtubes, etc. are made from mild steel. It&#;s also safe to group them into here.
I also put my own preferences in here, and tried to note wherever I did.
There are many ways to weld a bike frame together that won&#;t fall apart. But a few extra steps here and there can help make sure it doesn&#;t explode as soon as you huck it off a big drop or two.
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Machine:
Any machine capable of High-Frequency start DC Tig welding is adequate. A foot-pedal control will make the process much easier. It is possible to do without a foot pedal control, but I don&#;t recommend it.
I have an Everlast Powertig 210EXT. This particular model is way overkill for welding bicycle frames, but I need the extra bells and whistles for some of the other welding I do.
I&#;ve been happy with mine, Everlast seems to be a great value for the home-gamer.
They do have cheaper models that would work great. Just look for one that has high-frequency start, and a foot pedal.
Torch:
A #9 Air-cooled torch is my preferred. It&#;s nice and small, and fits into tight places well. The max rated amperage is 150, so it is adequate for bicycle welding. You could theoretically go with a #24 air-cooled, (which maxes out at 80 amps) But then you will end up having to wait for it to cool down between welds. Their amperage rating is typically based on a %20 duty cycle, so you cannot run the rated amperage continuously.
Water-cooled torches do exist, but in my opinion they are just not worth it for bicycle welding. The added cost and complexity don&#;t make sense for the home-gamer like me welding the occasional thing. If you are a production welder, that&#;s a different story. Different tools for different applications.
A very nice torch to have is what&#;s known as a Flex-head torch. This allows you to bend the head around whichever way you like, and it&#;s definitely nice for welding bicycle frames. Their cost is not much more than a &#;regular&#; non-flexible torch. I highly recommend them.
(don&#;t try this at home with a non-flexible torch
Another nice thing to have are the super-flexible hoses. Not required of course, but definitely nice.
Cups / Gas lenses:
The &#;standard&#; (also read: cheap) setup is what is known as a collet body. These have a few small holes where the Argon shielding gas comes out, and then the purpose of the cup is to redirect it onto the weld and tungsten. They do work, but gas lenses are much better at this. They have a (or sometimes multiple) screens to help diffuse the gas and provide a much smoother flow and weld coverage.
I typically use a gas lens and a standard #8 alumina cup. They are relatively cheap, and can accomplish every weld on a bicycle frame (most of the time). If you&#;re just starting out, this is my recommendation.
A small back-cap is also highly recommended. I typically use the mid-length style, that way I don&#;t waste as much tungsten. The small button-caps do come in handy though.
The oversized cups, and the pyrex cups can be nice, but definitely not a requirement. In fact, the glass pyrex cups offer little to no practical benefit over their alumina counterparts. They look pretty though.
#8
alumina cup&#;standard&#; collet body & cup vs. gas lens andalumina cup
Tungsten:
Don&#;t get too caught up in the different types of tungsten. If you are a robot, you may notice differences in arc stability and tungsten longevity. But if you&#;re anything like me, you&#;ll end up contaminating your tungsten and re-grinding it long before any benefits can be realized.
The old-school preferred is %2 Thoriated (Red). It is being phased out though, breathing in grinding dust from the thorium is not good for you!
A great alternative to thoriated is %2 Lanthanated (Blue). It will do everything you need it to, including aluminum on an inverter machine.
1/16&#; is a good size for the amperage ranges we need. 3/32&#; or 0.040&#; will work, but 1/16&#; is a good goldilocks. 0.040&#; can be hard to find sometimes.
Filler Metal:
0.040&#; ER70s-2 is my recommendation.
Smaller diameters can be nice, but they&#;re also hard to find sometimes.
I&#;ve used 1/16&#; on bicycles before, but that&#;s because I&#;m a sucker for punishment. I don&#;t recommend it if you want your welds to look good. A rule of thumb is that your filler diameter should be the same, or smaller than the material thickness you are welding.
The type of filler is a big can of worms though, so if you want to know why keep reading. Otherwise skip this bit and just get some ER70s-2.
Strength, Ductility, Toughness, (and all the others) are different material properties we often refer to. It&#;s important to be a bit pedantic though. If you say &#;I want my welds to be as strong as possible&#;, what exactly do you mean?
I won&#;t type out an entire materials science class here, but generally speaking, Toughness and ductility are much more desirable for a bicycle frame than ultimate yield strength.
Ductile things bend before breaking, brittle things break without warning (also see: carbon fiber).
The definition of toughness is the ability of a material to absorb energy and deform plastically without fracturing (also see: not-carbon fiber)
(Note: I&#;m making fun of carbon fiber here, but just realize that carbon composites are indeed very strong, they just typically do not have much toughness or ductility)
But, ER70s-2 is weaker than ?!?
Yes. This is okay for a couple reasons.
One, we are gaining ductility in the weld by having an under-matched filler. So if your weld is not perfect, that ductility can help make sure a crack does not propagate.
Also, weld size. Essentially all the welds you will do on a bicycle frame will be over-sized. This is good. It essentially means the tensile strength of the filler is irrelevant, since we have more of it.
Another gross over-simplification rule-of-thumb is to have fillet welds be the same size as the material thickness. Now, with bicycle tubing being roughly 0.035&#; in some cases, that means a 1/16&#; (or larger) fillet is way overkill. Again, this is a good thing for us.
What about ER70s-6?
This one is also fine. It&#;s the most common out there, and it&#;ll work just dandy for bicycle frames. Mechanically, it&#;s essentially the same as ER70s-2.
The benefit of the -2 variant is that it has more elements added to the filler that help clean and de-oxidize the weld.
ER-70s-6 relies on Silicon only. It works, but -2 works better.
This is especially nice for welding without back-purge. After all, ER70s-2 was originally designed for welding open-root carbon steel pipe with no purge.
In an effort to provide some references / further reading, Miller Electric has a great write-up here:
https://www.millerwelds.com/resources/article-library/best-practices-for-tig-welding-of--chrome-moly-tubing-in-general-motorsports-and-aerospace-applications
They also have a nice sort of WPS (welding procedure specification) in there that is handy if you&#;re just starting out.
So in short, ER80s-D2, and the Weldmold variants are not the best choice for the vast majority of bicycle applications. (And they&#;re more expensive!)
(Also a bit of a rant / tangent. Weldmold doesn&#;t provide the chemical composition of their fillers. Or at least I can&#;t find it on their webpage. That alone is enough for me to make sure I never touch the stuff!)
Welding Stainless to
I try to avoid buying dropouts and such made from stainless, but they do have their purpose.
In this case, it is best practice to use a 309L filler to join the stainless to the .
This is not ideal, but it does work. Pay close attention to the heat and keep it as cool as possible while welding. Carbide precipitation will happen if it remains hot for too long.
It&#;s also a growing trend in the community to use 3D printed (metal) parts on bicycle frames. They are typically stainless, and this is a new and emerging technology. I&#;m gonna wait a few years before I weld any to 3D printed stainless. Some builders have had good experiences with it, and others have had very bad experiences with it. We don&#;t know what we don&#;t know (yet).
I will also stick my foot in my mouth here and say that Weldmold 880 might be better for this application. It is allegedly similar to 309L, but since it&#;s proprietary we really have no idea what it is.
Machine Settings:
Amperage / Foot-Pedal Control:
1 amp per thousandth of material thickness is a general rule that works well. For example, 0.035&#; tubing would be 35 amps. Note that in bicycle welding we are typically joining thin tubing to thicker other stuff.
With a foot-pedal control, I typically set the machine to 80 amps, and then rely on the foot-pedal to control the actual amps during the weld. Somewhere around 50-60 amps is where most of my bicycle welding ends up being. Having the machine set higher allows for more headroom, but having it too high will reduce your fine-control.
For those that don&#;t know, the foot-pedal control is 0% to %100 of the setting on the machine. So for example, let&#;s say our target amperage is 50.
If we set the machine to 50, then we mash the pedal to the floor and get 50 amps.
If we set the machine to 100, then we press the pedal halfway to get to 50.
If we set the machine to 200, then we would only press the pedal a quarter of the way to get to our desired amperage.
With that last example if we&#;re clumsy on the pedal, we can very easily overshoot that and then blow holes in our tubing.
Unless I&#;m welding aluminum, I typically just add roughly 20 amps to what I think I will need and set the machine to that. A little extra headroom is nice sometimes.
Pulsing:
Pulsing is definitely not a requirement for good welds, but it can be nice in some cases.
I generally group pulsing for Tig into two types. Low-speed and High-speed.
Low-speed pulse is what I refer to as roughly 2 pulses per second (PPS) or less.
This can be nice for getting super-consistent ripples (stack of dimes) in your weld bead. It can also lower your heat input when done correctly.
High-Speed pulse is what I would consider roughly 20 PPS and up.
The biggest benefits are lower heat input, and control of the puddle. The high speed pulse tends to agitate the puddle and keep that molten metal &#;stuck&#; to exactly where you tell it to. This is nice for welding thin tubing, but I actually rarely use this. Old habits and such.
If the price of a Tig welder is a concern, don&#;t feel bad about skimping on a pulse feature. If mine magically got taken off my machine I wouldn&#;t really care. I never use it.
Gas Shielding:
The biggest thing about gas shielding is making sure you have enough. Not enough means you will have porosity, and other issues that will lead to a bad weld. Too much simply means you&#;re wasting Argon. Waaaaaay too much can actually cause enough turbulence to draw in ambient air and can cause the same thing as too little.
With a #8 gas lens, I typically run 15-20 CFH.
A little pre-flow is nice if your machine has that setting. Typically 0.5 seconds is sufficient.
And enough post-flow to let things cool down while still shielded. 10 seconds is typically just fine.
There&#;s another can of worms with this one, and I will link a post I made a while back on IG. The summary though, don&#;t get too caught up with the pretty colors. They don&#;t tell you anything without more information.
https://www.instagram.com/p/CQV_3T8BS6d/?utm_source=ig_web_copy_link
Back-Purging
For those that don&#;t know, back-purging (or just &#;purging&#;) means adding shielding gas to the inside of the tubes as you weld.
The short version is that it&#;s simply not necessary, unless you&#;re working with stainless or titanium. But titanium is way outside the scope of this guide.
I will note though, purging your tubes can have a nice benefit if you&#;re not as experienced at welding, and / or your fit-up is not great. Basically if you way over-heat your welds, or have bad fitup, you can draw in oxides from the backside of the unshielded metal into the molten weld metal. This is bad. Having a purge on the backside helps prevent those oxides from forming in the first place.
My recommendation is to not worry about purging for .
Heat Sinks
Heat sinks are great. Bicycle tubing is very thin, and welding is very hot. That heat has to dissipate away from the welded area somehow.
In practice, the heat tends to stay in the welded area, and will contribute to distortion and other issues. So large pieces of copper, aluminum, bronze, or any of the other copper alloys make great heat sinks. I won&#;t go into those in detail here, because I don&#;t use them for bicycles. I&#;ll let the more experienced folks share how they make their heat sinks.
In short, you can get perfectly acceptable welds without worrying about heat sinks. Proper weld sequencing, patience, and good technique are vastly more important than using heat sinks.
I think that&#;s enough for now. This kind of turned into a brain-dump, and trying to demerit some of the rumors / misconceptions I tend to hear about welding thin-wall tubing. I hope this helps some of you all! Let me know if you have any questions or other things I should add.
(Edit: the title of this post was a joke on the &#;for dummies&#; books that are so popular. I can of course change that if it&#;s inappropriate)
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