Experiment: TIG welding aluminum with flux

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I've been meaning to try TIG welding aluminum with flux for a while, and finally got around to doing some initial experimentation.  I used some 1/8" flux-cored aluminum welding/braizing rod I had handy (rather than aluminum welding flux, which I've got at another location, but wasn't handy at the moment.)The initial results with just using the flux-cored filler rod are, the flux on the front side makes it hard to see what's going on with the puddle underneath it, and made the TIG arc react differently.  The flux flared up on one or two occasions during the welding process.  But the flux definitely provides some shielding from oxides, and allows the puddle to penetrate through fully to the back side (provided there is adequate heat input, such as when the front of the puddle "sags").I performed the tests on 1/8" 6061 coupons, butt welded, with approx a .030" gap setup, using Harris 1/8" COR-AL flux cored aluminum filler rod.  (The gapped setup allowed the flux to be carried around through the joint to the back side of the weld.)  I set up the weld coupon using tack welds done without flux and on my initial test used AC TIG.On the initial test, I didn't give enough heat input to consistently penetrate through to the back side, although I did reach full penetration in a couple spots.  On those spots, notably the flux did seem to effectively shield the oxides and allow the joint to be smooth on the back side, just like when oxy-fuel aluminum welding with flux.The flux cleanup as expected from my experience oxy-fuel aluminum welding, is an unpleasant chore.  Hot water and VIGOROUS scubbing with a wire brush were required all along the weld joint... front side and back sides. Attached ImagesLast edited by jakeru; 02-21-2011 at 12:24 AM.
Reply:Looks like you learned your lesson.AWS certified welding inspectorAWS certified welder
Reply:Was this a test to see if it was a viable option if you had a really dirty casting that could not be 100% cleaned, or just a "I'm bored, I'll see if this works"I've always meant to try brazing with DCEN TIG, but have never gotten around to it.E-2C Hummer PilotLincoln IDEALARC 300/300 TIG Welder Lincoln AC/DC 225/125 BuzzboxLincoln Weld-Pak 155 MIGForney (Harris Style) TorchesoooooOoooooWhen in doubt.. ADD POWER!
Reply:For my second experiment with TIG welding aluminum with flux, I tried using DCEN mode rather than AC welding mode, relying on the flux to remove oxides from both the front and back sides of the weld joint.  I also used more heat input (allowing the joint to "sag" to get more full penetration) and used more of a "lay wire" rather than a "dip and pause" technique of adding filler rod.  All other parameters were the same as in the first experiment (1/8" 6061 test coupon, 1/8" COR-AL filler rod, .030" gapped joint fit-up.)As with the first experiment, it was hard to see the puddle through the flux (and the occasional flux flare up), but the flux did work to remove oxides even DCEN welding mode.  I penetrated this joint fully along more of the seam than I did with the initial experiment, and had no problems "re-melting" a portion of the joint and adding additional filler rod in one area.  (although I'm sure with extra practice, I could get more consistent penetration, and in only one welding pass.)The result is, the flux did an adequate job of shielding the front and back sides of the weld joint using the TIG DCEN welding process with argon shielding gas.  The aluminum metal *can* be joined together using only flux to remove the oxides with the TIG welding process, either in DCEN or AC welding mode, with argon shielding gas.I am also fairly confident that with appropriate diameter filler rod (and separate painted on welding flux) that this technique could be extrapolated to either much thinner or much thicker materials, due to the heat control offered by the TIG torch.  Further, the flux seems to help heat transfer more uniformly and the puddle to flow more evenly compared to flux free gas shielded TIG welding.  Although the flux does seem to interfere a bit with the TIG arc (not really explored in this experiment so far how exactly that works.)  The flux does make a mess, and I would probably next time skip using the gas lens on this.Almost forgot to mention, in both of these experiments I configured the pieces so the back sides of the weld joint were exposed to the open air, and not against a backer/chiller block. Attached Images
Reply:Originally Posted by MasterWas this a test to see if it was a viable option if you had a really dirty casting that could not be 100% cleaned, or just a "I'm bored, I'll see if this works"I've always meant to try brazing with DCEN TIG, but have never gotten around to it.
Reply:FYI CorAL is 4047, so a brazing material and flux. It is NOT a welding filler nor does it contain a welding flux, the active termperature of the flux is too low for proper fusion welding. The carbon arc and tig ( yes it was common once ) backing fluxes were of different chemistry than O/F fluxes.
Reply:I guess I just don't understand this whole "experiment".If the goal was to produce a lousy bead, full of porosity, that looks like bird droppings, I'd say you accomplished your goal.There's a reason they call it TIG (tungsten INERT gas) welding.There's a reason flux is used in OA brazing.  Doesn't really have anything to do with tig.  Adding a reactive substance to a tig bead is generally considered "not a smart thing to do".Personally, I wouldn't want anything shown in your photos leaving my shop.PS.  After seeing a guy tig welding on a wooden tabletop, I guess I shouldn't have expected anything else.Last edited by SundownIII; 02-21-2011 at 01:03 PM.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Hello jakeru,Thank you for sharing your tests and detailed results. You are satisfying a curiosity I had, just maybe one day when cash allowsa TIG machine will be had by me and I to will run similar tests of my own curiosity.I have a question or two for you. Are you using a Sodium (salt) filter lens?Do you plan on testing pure CO2 just for shielding and cooling the tungsten and torch?Do plan to test some smaller filler with paste flux? (like .030 aluminum wire)Not seeing the puddle is nothing new to me. Burning 7018 I never see the molten puddle, slag puddle swirling, yes. A little more testing and practice I believe you will achieve nice looking welds.Again, Thank you for sharing!
Reply:Originally Posted by SundownIIII guess I just don't understand this whole "experiment".If the goal was to produce a lousy bead, full of porosity, that looks like bird droppings, I'd say you accomplished your goal.There's a reason they call it TIG (tungsten INERT gas) welding.There's a reason flux is used in OA brazing.  Doesn't really have anything to do with tig.  Adding a reactive substance to a tig bead is generally considered "not a smart thing to do".Personally, I wouldn't want anything shown in your photos leaving my shop.PS.  After seeing a guy tig welding on a wooden tabletop, I guess I shouldn't have expected anything else.
Reply:This is too funny. The guy never said he was going to put this on any customers work nor was he using this for himself. He never said he was out to impress anyone here, (I'm sure he knew he wouldn't). He was essentially just playing around. Yet everyone wants to bust his balls for experimenting. He was nice enough to post his results for people that don't know or were curious about this themselves. I for one actually wanted to know the results of this. But I damn sure wasn't going to experiment on one of my customers sheet metal intake manifolds. Thank you Jakeru for posting this up. I now know I will not be trying this.
Reply:Aaron - I don't know if COR-AL is really a 4047 alloy?  According to Alcoa, 4047 has only a 10F difference between liquidus and solidus.  (It can certainly be used as a welding filler alloy by the way; it is marketed for example here as a "welding filler wire" here.  I've also heard 4047's low melting temp and "fast freezing" characteristics can be favorable for some welding scenarios, such as when welding cast aluminum.COR-AL however has a 100F difference between liquidus and solidus (1055-1155F), and based on these temps, may be closer to 4043.  Even though not marketed as a welding rod, COR-AL seems to work OK for aluminum welding (melting and flowing with the parent metals) in my experience, tested with both oxy-acetylene flame as the heat source (as well as TIG in the above experiment.)I've got some tinman aluminum welding flux in my other shop; I'll have to try that out next with a more "traditional" TIG filler rod alloy.Sundown - The purpose of an experiment is to learn through direct observation.  But if you want to just follow instructions that others give you, (and leave the learning and innovating to others), that's your perogative.I don't see any porosity in the surface of the weld bead (which isn't to say the surface wasn't "textured" from the flux sitting on the surface during welding.)  Perhaps I will go ahead and cut / section and polish the weld bead to see if there are any air bubbles trapped underneath the surface.As for weld bead aesthetics, if a weld is going to be ground down or machined after being welded, the aesthetics of the weld deposit wouldn't be very important.  But I agree, I prefer the "as welded" look of a weld bead obtainable by TIG welding without any flux covering the surface.Both aluminum welding flux and argon gas shield atmospheric contaminants from the hot aluminum being welded.
Reply:I wouldn't consider this a "learning and innovating" experiment and would actually be considered the opposite. Not to offend SDIII but he has been around long enough to see things come and go and may be abrasive in his replys but that doesn't he is in the wrong. If you want to innovative then start from the ground up, develope your alloys and flux from scratch and then your proceedure. Grabbing stuff of the shelf and using it for something else to see if it works is not innovation. zlick you should disregard this post it seems that it would hurt you understanding of tig alot more then help.
Reply:Zlick - you're welcome.  To answer your questions, I was using my usual TIG arc welding helmet, with comparable settings I would have used otherwise for TIG welding without flux.  Pretty much a run of the mill autodarkening helmet, set at shade 11.  It has a green tint.  The sodium flare was "noticeable" as times, but didn't overwhelm the puddle view like it can through say, a standard green tinted shade 5 oxy-acetylene welding lens, when oxy-acetylene aluminum welding.I don't plan on testing CO2 gas because: 1. I think it will not adequately shield the hot tungsten (that is why I understand CO2 gas mixes do not work for TIG welding, where they do work acceptably in some MIG welding scenarios), and 2. I don't have any CO2 readily available to play around with.Yes I would like to test some other variations along these lines of TIG welding aluminum with flux.  Next I think I will test some separately applied flux (I have some Tin Man Technologies oxy-fuel aluminum flux that should fit the bill) and a more traditional (smaller) diameter and alloy TIG filler rod.  I agree that putting down a more uniform deposit thickness (with consistent, full penetration) seems like it would only be a matter of some extra practicing time away.  The puddle, although hard to see through the flux, was readily controllable and seemed to "wet out" nicely in particular on the back side, where it fully penetrated.
Reply:jak,The problem I have with posts like this is that what you're trying to "personally observe" has already been proven unsatisfactory and documented in many recognized welding manuals.  However, if you're the type who doesn't believe anyone else when they tell you that fire is hot, go right ahead and stick your hand in the flame."Penetration" is not measured by how much crap flows thru to the backside of the bead.  When you're dealing with filler with a considerably lower melting point than the base metal, what you're seeing is to be expected.The problems with this type "experimentation" is that it brings out questions about "can I do that rather than buying a proper tig machine?"  Classic example is Zlick's post.  He's all ready to "give it a whirl", right after he gets his question answered about whether he can use CO2 for a covering gas for tig.You're right about one thing though.  I'd rather read "documented results" in Miller's, Hobart's, Lincoln's, ESAB's, AWS, etc, etc. manuals, rather than some new welder playing around on his kitchen table.The research is out there.  All you need to do is read it.  The problem with the internet/message boards is that it's made a whole generation lazy.  It seems to have, for some, become their sole reference source.  The problem is, there's as much bad informaion put out on some message boards as there is good information.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Sundown, please provide me with your reference(s) where GTAW Aluminum with shielding flux has been explored.  I would really like to read what was tested and what their results were.  I've read various literature on welding, and have yet to come across any such references.Also, the COR-AL filler rod I used has very similar melting temperatures as 4043 TIG filler rod, as I've already noted above.  If you've managed to make a 4043 TIG weld without flux wet out smoothly on the back side (as I've already determined based on above experiments is possible with the flux), then let me know.What I've found from observation of my own as well as other's TIG aluminum welds, is that oxides on the back side seem to impede the flow of the weld bead where full penetration has been achieved, and prevent it from wetting out.
Reply:jak,I'd recommend you start with Lincoln's Procedure Handbook of Arc Welding.  Not only will it walk you thru the evolution of the GTAW process, it will discuss the submerged arc process.As one who's been welding for more years than I care to discuss, you new guys would be much better served spending the time refining your technique using established procedures than you are trying to reinvent the light bulb.As you develop your understanding of the different processes available, you'll better understand why a well equipped welding shop will have not only a tig machine, but also O/A, SMAW, GMAW, GMAW-P, etc, and know when each best meets his needs.When you talk about "grinding the bead down" on aluminum, you've already told me that you have a lot to learn about the metal you're dealing with.  Aluminum is not your daddy's mild steel.It's  one thing for a hobby guy to "play around" but don't try to push this garbage as a "viable alternative" to a tried and true process.  Same thing with the electronics buff, who's more interested in souping up his harbor freight stick machine than he is in learning to weld.Welding, especially when you take into account the metalurgy, fabricating, etc is a never ending learning process, even when you "stay between the dotted lines".  These attempts to "remake the wheel" will most likely hinder you from ever becoming really proficient.  The unfortunate part is that you may drag a few of the newbies with you.  Here I'm talking about the guy who's always looking for shortcuts to make up for his lack of commitment to "the art of welding".Are there certain advantages to gas welding aluminum (with flux).  Sure, and there are a few guys here who can discuss them in more detail than I can.  Will anyone claim that, considering the experience involved and the cleanup necessary, that it's a viable alternative to proper tig welding. I don't think so.  What you've done here, is take the most UNDESIRABLE aspects of GTAW and OA welding and combine them. (slow, pre-weld prep, and post weld cleanup).  And all this to achieve an undesirable finished product.Last edited by SundownIII; 02-21-2011 at 05:59 PM.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:There have been people on this site that have posted pics showing full pen welds on Al that have the back side of the bead nearly appearing to have the same look as the front. These guys must have a higher degree of skill in seeing what happens in the puddle when welding Al.Isn't the whole point of the tig process is to have an inert environment for the electrode, filler metal and weld puddle. This why I wonder why you are doing this experiment as it seems pointless and goes against what the process is suppose to be.
Reply:jakeru thanks,I did my homework and dugh, CO2 is not inert. Pretty dumb and not thought out on my part, when the shielding is to prevent contamination, and not to introduce them. Cost was my only thought at that point.Why does Stainless work with flux backing when purging is not possible?Why is Dual Shielding acceptable with other processes? Originally Posted by ESAB - Tony Anderson CEngA short history of welding aluminumFor more specialized applications, we can find GTAW used in the direct current electrode negative mode (DCEN).  This method provides arc concentration of about 80% of the heat at the base material and about 20% at the electrode.  This results in relatively deep and narrow weld penetration, and very little, if any, significant arc cleaning during the welding operation.  Typically used with pure helium shielding gas, this method of welding is capable of welding much greater thicknesses of material (up to 1 inch) and is most often used in automatic seam welding applications.  The third mode of GTAW is the direct current electrode positive (DCEP).  With this method, we have about 20% of the heat generated at the base plate and 80% at the electrode.  We create excellent cleaning action but very shallow penetration.  This is probably the least used method of GTAW.
Reply:Hey jake,I gotta agree that your "experiment" is one of futility. I've been alum. welding before the days of "heli-arc" with O/A, then "heli-arc"(GTAW/TIG), & MIG(GMAW/P) with absolute success. Why would I need to go to a cross-method of processes when there is no reason? As far as documentation, why would any research provide all the data for failures in such an experiment? All research/testing data is to provide successes with processes. I do very light(.062 for the aesthetics if needed, & MIG for all the production applications. Each process has its' merit & practice with each with established guidelines provide superb results. Why fight successes?Now, as far as using SMAW w/flux rods, new member B_C who just signed on can really fill your cranium with his successes & pics. He has mastered alum. SMAW. Give him a shout(PM) or respond to one of his postings/threads.DennyComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:Jay O,The term "full penetration weld" is one of the most thrown around and misused terms in aluminum welding.  Generally comes up when people do not understand aluminum and the difference between it and mild steel.Lets take 1/8" aluminum plate for instance.  Do a "proper butt weld" between two pieces.  Leave the bead proud as welded.  Turn the pieces over.If the weld was done correctly (proper amps/travel speed) you will notice that the bead barely (if at all) breaks the backside surface.  Does this mean that it is a bad bead (underpenetrated)?  No.  That's exactly what it should look like.  Additionally the proud weld bead on the face side adds to the strength of the weld.  That's why it is generally not a good idea to "grind down" an aluminum bead.Now take the same base material.  Run a "hot bead" too slow down the seam.  Turn the material over.  You'll see a lot of melting on the back face of the material.  Did this add to the strength of the weld.  NO.  What it did was create a larger than necessary HAZ.Now do a "bend test" on both samples.  Example 2 will fail before example 1 (nearly always in the HAZ) because we negatively affected the base metal (weakened it) by overheating the material to "achieve full penetration".  In Jakaru's example, if he ground the convex bead down to achieve an acceptable cosmetic appearance, he'd have nearly no strength left in the weld even though he achieved "full penetration".This probably wasn't the best of explanations, but suffice to say that there's a big difference in welding aluminum and welding mild steel.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by jakeruSundown, please provide me with your reference(s) where GTAW Aluminum with shielding flux has been explored.  I would really like to read what was tested and what their results were.  I've read various literature on welding, and have yet to come across any such references.
Reply:Ok for some reason im not getting through here. The electric welding fluxes are a different chemistry than O/F flux.............got it? Now each process has its strong points, and not ONE process is ever a replacement for another. The strength and weakness of the OF process is the flux. Makes the most dense, flat beautiful welds on sheet.....but has to be cleaned off.....kind of a double edged sword. Tig was created primarily for the welding of joints where flux could not be cleaned out. Simple as that!
Reply:Originally Posted by SundownIIII guess I just don't understand this whole "experiment".If the goal was to produce a lousy bead, full of porosity, that looks like bird droppings, I'd say you accomplished your goal.There's a reason they call it TIG (tungsten INERT gas) welding.There's a reason flux is used in OA brazing.  Doesn't really have anything to do with tig.  Adding a reactive substance to a tig bead is generally considered "not a smart thing to do".Personally, I wouldn't want anything shown in your photos leaving my shop.PS.  After seeing a guy tig welding on a wooden tabletop, I guess I shouldn't have expected anything else.
Reply:Originally Posted by SundownIIII guess I just don't understand this whole "experiment".If the goal was to produce a lousy bead, full of porosity, that looks like bird droppings, I'd say you accomplished your goal.There's a reason they call it TIG (tungsten INERT gas) welding.There's a reason flux is used in OA brazing.  Doesn't really have anything to do with tig.  Adding a reactive substance to a tig bead is generally considered "not a smart thing to do".Personally, I wouldn't want anything shown in your photos leaving my shop.PS.  After seeing a guy tig welding on a wooden tabletop, I guess I shouldn't have expected anything else.
Reply:Just having some fun, don't take it personal....you kinda set yourself up when you took pictures......LMAO......Hey what would Mc Guiver do?  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig RockAnd here is yet another thread that is deteriorating quickly.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Yeah that happens when you get OLD GUYS  talking about things, they ramble on and on and then forget what they were talking about and Bla bla bla ........  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Originally Posted by zlickWhy does Stainless work with flux backing when purging is not possible?
Reply:Originally Posted by makoman1860The electric welding fluxes are a different chemistry than O/F flux.............got it?
Reply:jake,Can I make a couple comments/ask a few questions?(Oh well, what the heck.)You've had your tig machine for two or so years now.  I've seen where you've taken it apart to analize the innards and compare it to different versions of the same model.  I now see you off on a tangent, trying to re-invent the light bulb.  In other words, a lot of stuff totally unrelated to developing proper tig welding skills.Now the questions.How much argon have you used in the last 24 months?How many coupons have you melted in the same timeframe?How many pounds of filler have you used?These are some of the things that will make you a better welder.  Not this other hokey BS you seem to want to "play with".Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:http://www.alcotec.com/us/en/educati...e/qa/index.cfmhttp://www.aluminum.org/source/Order...tRow=1&PageNumEd Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Unfortunately, welding is not the only area where people spend a lot of time re-inventing the wheel.  I think it is mainly caused by the loss of the foundational basics which were once required learning before you got into the hands-on applications.  It seems most people are interested in some quick-fix approach to learning so that they can get into the "big money" jobs right away.  They are even told they are "experts" after taking courses with no hands-on experience.  At one time, 5 year apprenticeships were common and 5 years as a junior engineer was likely.  Not so anymore; everyones an expert right out of the box.  Well, just to say it one more time, There are no quick fixes for obtaining skills and experience, welding or otherwise.  Get the basics down and then proceed.  It will save you a lot of time and frustration in the long run.  There, I feel better now!
Reply:I think this is an excellant experiment. You may have combined an excellant combo. For a guy working at home who doesn't want to buy another welding machine.I've read about people using dcen to weld thick aluminum with helium. I've only done ac with argon. I'm a little busy overseas right now. However when I get back stateside in a few months I may continue your experiment myself. I'm gonna get a wooden table too just to irritate people as that seems to have worked well for you. I'll go to garage sales till I find the perfect table he he.Anyway thanks for posting this. You've given me a better place to start with my little dcen only combo welder back home.
Reply:I tested a slightly different approach. I used normal TIG rod and separate flux, normally used for gas welding aluminum. That let me use minimal flux for better visibility and easier cleanup. If you don't have access to one of the preferred processes, it seems like a useful tool in the toolbox. Here's my page with photos and discussion.http://hildstrom.com/projects/dctiga...lux/index.htmlYouTube, Website
Reply:Originally Posted by 3 weelin geezerCrazy!  such harshness...... Oil is not going to run out b/c of a burn spot on a table.
Reply:Originally Posted by zlickHello jakeru,Thank you for sharing your tests and detailed results. You are satisfying a curiosity I had, just maybe one day when cash allowsa TIG machine will be had by me and I to will run similar tests of my own curiosity.I have a question or two for you. Are you using a Sodium (salt) filter lens?Do you plan on testing pure CO2 just for shielding and cooling the tungsten and torch?Do plan to test some smaller filler with paste flux? (like .030 aluminum wire)Not seeing the puddle is nothing new to me. Burning 7018 I never see the molten puddle, slag puddle swirling, yes. A little more testing and practice I believe you will achieve nice looking welds.Again, Thank you for sharing!
Reply:I think Im pretty sure that liquid Argon is colder than CO2. Maybee the temps are different in gas vs. liquid tho. Liquid Helium is even colder and used for cooling MRI magnets.One thing I learned in this thread is, SD III does know what hes talking about and even has useful information but; hes kind of abbrasive and thats putting it mildly
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Reply:kingnero, thanks for the good video on how to use that aluminum brazing rod. It is definitely useful for repairs, but it can be difficult stuff to use if you want to build something with more than one joint. When I tried multiple joints a few years ago it seemed that by the time my next joint was hot enough to braze, my previous joint was melting and falling apart. The right fixtures, cooling, or pinpoint heat source might be able to work around that problem on smaller parts.YouTube, Website