Tig Welding can be a black art if you start on your own with no direction. All too often we see first time TIG Welders struggle with the basics and this can lead to frustration and a long learning process. TIG welding aluminum can be more difficult than steel; even with a simplified TIG welder like the Eastwood TIG 200 AC/DC. Aluminum tends to be less forgiving and there are some simple steps you can take before, during, and after the weld that can help you successfully weld aluminum. I decided to throw together a few common mistakes and corrections for beginners when learning the “black art” of TIG welding aluminum.
“Cleanliness is next to godliness”- Cleaning your weld surface and keeping everything you do as clean as possible when TIG welding makes a world of difference. This is even more important with aluminum, taking extra steps to clean your parts as good as possible will help you make a clean and strong weld. Above you can see a piece of “clean aluminum” that I pulled off the shelf and welded on. You can see the brown halo around the weld and spatter of dirt that was forced from the weld. In the grand scheme of things the aluminum was “clean” but not enough for TIG welding. The second a piece of bare metal is exposed to the atmosphere it starts oxidizing on a molecular level. This oxidation will take a while to be visible to the naked eye, but it’s happening. I suggest to at the least use a dedicated stainless wire brush to scuff the surface of the aluminum until you have a dull, brushed finish. You can also use a fresh sanding pad or disc as well. I then suggest to follow up with Eastwood Low VOC PRE, Acetone, or a similar chemical. DO NOT under any circumstances use a brake cleaner-type product as they contain a chemical that when heated or burnt creates what was once known as “mustard gas” and can be DEADLY. Our Low-VOC PRE and Acetone are safe to use, and are the preferred solvent to clean parts one last time before welding.
You’re settings mean a LOT- Even on a simplified machine like our TIG 200 AC/DC the extra dials used for aluminum can be confusing, even more so if you’re learning on a higher end machine with lots of dials, switches, and “blinky gauges”. The clearance effect or AC Balance control is the most important dial to learn when welding Aluminum with your TIG welder. This dial will essentially change the “sine wave” of the AC welding process. This dial will change how long (we’re talking fractions of a second) the welder will stall on electrode positive to electrode negative to gain either more cleaning or more penetration into the workpiece. On the Eastwood TIG 200 this dial is called “Clearance Effect” and goes from -5 to +5. The more negative you go on the dial will net you greater penetration and a tighter arc/weld puddle, but less cleaning of the workpiece. If you go more positive the puddle gets wider and more cleaning of the base metal occurs. In this case the heat goes more into the torch itself. There’s a reasonable limit how far you can go positive on the Clearance Effect, much past 0 will cause the electrode to get overheated and start balling up or potentially fracturing at the end. You can see the pics above of an electrode that was overheated due to incorrect settings.
There are a few ways you can “cheat” this setting. I highly suggest converting you torch gas nozzle and collet body to a gas lens to achieve better gas coverage and more efficient cleaning. The added shielding coverage when using a gas lens allows you to turn your setting more towards the negative side for a tighter arc and weld puddle. Cleaning your workpiece as much as possible can also help since the machine doesn’t have to work as hard to clean the metal. Also remember that there are many grades of aluminum which can change where you set the dial on the machine (IE- older low quality castings vs. fresh new plate aluminum).
Wait for it, Wait for it- Patience is something that is tough sometimes, especially when you have so many things going on at one time when TIG welding. A big mistake we see beginner TIG welders make when learning how to weld aluminum is not waiting for the puddle to fully initiate. Like we talked about in the paragraph above, when welding on AC the welder actually cleans the base metal before the aluminum turns molten. This means you will have to wait a few seconds before a puddle starts. This time will vary on your amperage, clearance effect (AC Balace), and how clean your material is. Above you can see the process of starting a puddle in aluminum. At first the arc will turn a small circle of the metal white, then the area will increase in size and the “eye” of the puddle will begin get shiny and turn into a liquid. Shortly there after the puddle will open up and start to get larger. Once you have a puddle thats the desired size you can begin to add a dab of filler rod, move forward half the puddles diameter and add another dab of filler. Just make sure that the area is staying clean around the puddle and there isn’t black specks floating in the puddle or brown halos around the puddle.
“Bad Form!”- How you hold the TIG torch is a lot more important than some beginners realize. The weld arc travels straight out of the electrode and the more direct its path can be to the workpiece, the smaller your arc will be and the less you’ll heat the base material up. A bad habit many beginners learn is “laying the torch down” when welding. This happens without you realizing it because you’re probably trying to turn it to see the puddle and tip of the electrode better. A good rule of thumb is to tilt the torch back 10-15 degrees from the way you’re traveling on the work piece (left to right for a lefty and right to left for a right handed torch holder). If you start laying the torch down too much on any material, the weld puddle opens up quickly and the workpiece heats up so much you could blow through the metal or the puddle grows uncontrollably large. On aluminum the other thing that happens is that the filler rod starts balling up or melting before you even try to dip it in the weld puddle and can cause a mess and a LOT of frustration. If you’re having this problem I can almost 100% bet you have your torch laid down too far. This can be a difficult thing to conquer when welding something that isn’t flat like round tubing or a wheel, etc where that 10-15 degrees changes as you rotate around the tubing. If you see your filler rod balling up too early or the puddle opening up try changing your torch angle mid-weld and see if that solves the issue. In the photos above you can see where I laid the torch down mid-weld and how much the puddle grew in size and then when I tilted it back up it slowly got smaller again.
Don’t pull away!- Most of us learn MIG or ARC welding before we tackle TIG welding. These types of welding it’s perfectly acceptable to immediately pull your welder away from the workpiece as soon as you’re done welding. This is a big no-no with TIG welding, ESPECIALLY on aluminum. This bad habit can be tough to break if you’re use to these other types of welding, but it’s necessary to break if you want to make sure your beautiful stack of dimes weld doesn’t fail! A few things happen when you immediately let off of the pedal and pull your torch away from the weld at the end of a puddle on aluminum, the first being that the molten metal is left without shielding gas for a fraction of second in which it is now vulnerable to being contaminated by the air. The other thing that can happen is that the weld is “shocked” from going from hot to cold so quick in that it could develop hairline cracks in that last bit of weld that WILL spread (Crack is bad Mmmmkay?). The process that I’ve tried to get myself into over the years is when you get to the end of a weld puddle, add one last small dab of filler as you slowly let off of the pedal. Let the amperage slowly bleed off until its down to nothing, then hold your torch over that area until your post flow shuts off on your machine. This will keep the shielding gas flowing over that vulnerable last weld and keep it from developing a crater and a crack at the end. Above you can see an example where I let off the pedal very quickly and immediately pulled the torch away on a hot weld. Even on a short weld like this there are small fractures that are already forming, not what you want on anything you care about!
In the end nothing can beat practice and repetition, but if you’re conscious some of the common mistakes others make you can correct as soon as they happen to you. Take your time and keep some of these key steps in mind and you’ll be on a path to close-up worthy welds!
-Matt/EW
I appreciate the information. It’s been a long time since I’ve welded. With proper planning, studying, and of course practicing, the goal is to eventually enter the welding profession again. This is insightful and relevant. Thanks much.
would of like to see all he wrote on on a video .and showing some of the mistakes and how to over come them a lot of good in fo read it carefully and learned a lot thanks joe.
Great info. Thanks for taking the time to do the article.
Thank you all for this amazing yet simple advise.
I am very interested in Tig art for landscaping. Retired vet lots of time. any info you can suggest I would be very thankful
George Quin, if your using an autodarkening helmet, try setting the filter to a higher/ie darker setting. If your not using an auto darkening helmet (why wouldn’t you?) then you need to change out your filter to a darker one. This should help you in dealing with how bright the arc is and make it easier for you to keep track of where you are trying to weld. Big difference between stick welding and MIG or TIG because you don’t have any flux to help “hide” the arc, so you gotta go darker.
This is a common problem when adding TIG ( technically GTAW – Gas Tungsten Arc Welding) to your skill set. The arc is much brighter than MIG or stick welding. The solution is to use a darker lens on your welding helmet. If you don’t have one yet, get a variable shade electronic helmet and use a progressively darker shade until you can easily see the weld puddle. Then you can set it back for the other processes.
It’s been many many moons ago but when I took a welding course at my local skills center, I first learned to oxyacetelene (gas welding). I did have some exposure to TIG as I progressed in the course and found that it was easier to pick up as it basically employed the same hand to eye coordination as gas welding. You learn the basis of welding through learning the gas welding process and like riding a bicycle you never forget. One can fall into bad habits and of course out of practice with time but when one returns to the basics, welding problems can be solved and then it is just practice, practice, practice
LOL Mark I saw that but your comment is exceptional haaaaaaa
Here’s your Sine!
thank you for the info .picked up some great tips . heading back out to shop, hope to correct a couple of my problems.
This article was worth reading just for the sentence below! Thank you. I was planning on using brake cleaner to clean some steel rod stock before welding.
“DO NOT under any circumstances use a brake cleaner-type product as they contain a chemical that when heated or burnt creates what was once known as “mustard gas” and can be DEADLY.”
Captions alongside the pictures would be most helpful.
That last sentence… so, brake cleaner should still NOT be used? I’ve been using brake cleaner for MIG and never thought about it (my brake cleaners are non-chlorinated)–not that it\\what I was doing was correct–I just never thought it left a residue. And, I never thought about it until reading this article. I would like to know if I can still use my brake cleaner or should go with a pressurized can of acetone? Or?
Thank you for the great tips ! And thank you for the huge tip about not using brake cleaner ! That alone could save some ones life !
I have 5 different welding certs from jobs I have worked on. 6G mig, Lo-Hy all position 7018 plate, coupon 6010 on pipe, 6010 downhill pipe and a couple others. I’ve never learned tig. I bought an Eastman tig 200-ac,dc. My prob is that the arc is so bright I cannot tell where the crack or seam to be welded is. I’d show you my practice pieces but it is too embarrassing. I’ll take any instruction I can get to try to get past my debacle.
Thanx,
George Quinn
Great article, I’ve got a high end red machine and it can be challenging to set compared to a machine like Eastwood sells. For a hobby welder like me I should have waited a year or so for the simpler machine. Thanks for a great article!
Good catch, typo/fat-fingered that one!
Hi Bob,
We don’t have a video on this article currently but our Youtube channel does have a lot of good welding videos you can watch anytime for free. Visit our page at: youtube.com/eastwoodco
Sorry I should have clarified, I was speaking exactly about that, the post flow should be at a proper setting and the torch held over the last bit of weld to assure it is shielded as it solidifies. We’ve found a lot of beginners tend to immediately pull the torch away which negates the post flow. I like to set the post flow to 3-3.5 seconds and the pre-flow to .2-.3 seconds. For steel I drop down about 1 setting as it doesn’t have the same issues as aluminum. Hope that helps! -Matt/EW
great information Thanks
As an experienced welder I always like reading tech articles especially those that make it easy to read.
This is a great article and it’s always good to see that Eastwood shares this with it’s customers.
Keep up the good work
Your suggestion to not use brake cleaner is quite valid, It is a bad choice because it can leave a residue. But, that being said; most brake cleaners no longer are chlorinated solvents, and do not create phosgene when heated, which was the concern in the past. Neither of the ones currently in my garage contained any chlorine, in fact; one was just acetone and heptane. If your brake cleaner contains chlorine, then that is still a concern, but otherwise, brake cleaners do not fully flash off and will leave a residue.
Liked the article very much. Use of correct American Welding Society (AWS) terms instead of welding slang would go a long way towards credibility with welding professionals and educators.
I received a greater understanding TIG welding than I received for a Wake Tech.
Thanks again
Dave
In the article on tig welding aluminum, you talked
about not pulling the torch away too soon. You didn’t
mention anything about Post-flow. Can’t you adjust
that so that you can back off the pedal, but leave the
torch close. The power will be off, but the gas will
still be flowing to shield the weld. I have a Tig 200
and the Pre-flow and Post-flow have quite a bit of
adjustment. What would you suggest the amount
of time on each setting for both steel and aluminum?
Good article, I still have some trouble on aluminum.
Practice, practice, practice. Thanks, Dick
Can you send me a video to show my students??
Thanks Bob Magee
Bob Magee
Automotive Engineering Design Instructor
Bergen County Technical High School
504 Rt. 46 West Teterboro, N.J. 07608
A 2012 National Blue Ribbon School
Best High School in U.S. News, Gold 2013
201- 343-6000 ext 7619
Fax # 201- 288-6028
973-838-1675 (H)
bobmag@bergen.org
bobmag922@gmail.com
The difference between ordinary and extraordinary is …. That little “extra”
Thought this short article on tig was great and picked up a lot of good information. I have taken a welding coursewhich centered on mig, stick and find it easier to relate a lot of what you were talking about. Explaining why things are happening was very useful to me and made things much clearer.
Appreciate the article, as I restore old snowmobile and want to get some aluminum skills. Thanks!
That would be “sine” wave not “sign” wave.