DC- Aluminum welding

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What limitations are there with this type of welding? Elaborate extensively
Reply:Your question is too broad. are you asking about using DC electrode negative for tig welding aluminum?
Reply:Correct
Reply:I hear it is real good for welding up tin foil hats....Who is John Galt?
Reply:Originally Posted by thermalfusioneng.Elaborate extensively
Reply:Originally Posted by jsfabSounds kind of demanding,,,,,,  kinda like the response you are looking for is "YES, SIR, I hear and I will obey, Sir!!!!"Assuming you can loose the attitude, I suggest you mosey on over to the Hobart Board, do a little searching first, there's been quite a few discussions about DC tig aluminum there already.   Also probably here, and on the Miller board also.  Did you even try the search function yet???   Anywhere???  Of course, using different key-words?On the Hobart board, anyway, I believe B_C and Pangea have experience.  Both are very nice guys, and very helpful, but ASK them, don't TELL them.
Reply:Hmm, I've been welding dc aluminum for years. Was hoping to get a more intelligible response than, I feel your picking on me! That's not my Intentions. A lot of welders have many misconceptions about this type of welding. My intention is to Hear what your thoughts are on this process. If I sounded to demanding my apologies, I should of said ( Please elaborate extensively) .My bad.Thanks
Reply:Yes, ZT, thanks for the heads-up. Originally Posted by thermalfusioneng.Hmm, I've been welding dc aluminum for years. Was hoping to get a more intelligible response than, I feel your picking on me! That's not my Intentions. A lot of welders have many misconceptions about this type of welding. My intention is to Hear what your thoughts are on this process. If I sounded to demanding my apologies, I should of said ( Please elaborate extensively) .My bad.Thanks
Reply:Originally Posted by thermalfusioneng.What limitations are there with this type of welding? Elaborate extensively
Reply:Ok I'll shoot. I do alot of marina repair work on the side that consist of alot of aluminum. I'd love for someone to show me how to weld the damaged pontoon railing I just finished with DC-- . I ain't gonna happen. My little dynasty at 45 lbs. along with a small 40 cf. argon bottle is very handy at welding anything I must go to. I'll take my ac/dc tig , in fact I'd be hard pressed to make it without one. I've made by far more money welding aluminum portable because there just isn't to many folks around here doing it. Another thing of all that aluminum work I have done none was thick enough for DC-- . It does have it's place but not for the majority of folks wanting to weld aluminum. Jmo.
Reply:sn0,Been through a few of his posts and "he's not".Thermal,Not going to go thru the whole speal but here's a few disadvantages to using DC-.Helium (generally a pure grade) is required.  Costs considerably more than Argon, plus due to the specific gravity (lighter than air) requires increased flow rates.  Most estimate that using Helium as a covering gas results in increasing your gas cost by a factor of 7.  In other words, your covering gas will cost 7 times as much.Arc is harder to start in Helium than it is in Argon.  Particularly true for the inexperienced welder.Base metal preparation is much more critical than AC welding since you do not have the benefit of the DC+ cycle.Much more difficult process to "master" than AC tig.Pangea (Hobart Board) is a big advocate for DC welding of aluminum.  He also works for NASA, who doesn't have the same financial constraints as most small welding operations.With the development/refinement of the inverter based machines Dynasty 350/700 in the Miller lineup and similar machines from Lincoln you have the "best of both worlds".  The balance range of the machines allows an experienced welder to obtain a near DC- arc (penetration) with just enough DC+ (cleaning) to achieve optimal results.I do blend a mixture of Argon/Helium for thicker aluminum but I haven't welded in straight DC for many years.  (yea, I know how.  Learned to tig on an old Linde (Heli-Arc) welder back in the 60's)Now why don't YOU tell us why you think DC- welding is SO GREAT.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:After reading most of your posts, The majority regurgitated half of someone else's opinion from some other website. Not good.I was hoping for some better input.Thanks for your input Showdog. I admire your candor.Thanks Sundown for the probable scenarios. In one of your other post you mentioned limitations, are these the limitations you where referring to? Are there others?I 'm no expert, but I still like to learn new things from credible people.Knowledge is power, few individuals get zapped by the sun, or get stuck in the desert.If you aren't sure about how to reply please don't, that's what gives welders a bum rap considering 4043 is not your house address.
Reply:Sorry Thermal,There's only room for one (and I'm not sure about that one) William McCormick on this board.If you want recognition here, you're going to have to learn to speak English, not riddles in some foreign tongue.We're waiting for your response (English please) as to the benefits of DC welding aluminum.  Up to this point what you've said is hogwash.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:If you had to get someone else to ask permission or if you need to get past the word regurgitate it ok I understand you have a (special situation). Yeah everyone here is just laughing about the niobium deal.good luck.
Reply:Follow these instructions carefully please.Put the pipe down, and step away from the computer.Oh, and BTW, I'm not your freaking Amigo.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:Oh come on chief , you think just because you can hurl some insults at someone that your not free game. Tuck your teeth in its not corn season.Oh BTW Ditto
Reply:Originally Posted by thermalfusioneng.Hmm, I've been welding dc aluminum for years.  A lot of welders have many misconceptions about this type of welding. My intention is to Hear what your thoughts are on this process. If I sounded to demanding my apologies, I should of said ( Please elaborate extensively) .My bad.Thanks
Reply:Bummer,I was hoping for something useful, 2 min. I cant get back. SQUARE WAVE 175 TIG   DUAL MIG 151
Reply:Hey thermalfusioneng,Your query is a bit confusing as to your goal. I believe SundownIII gave you the appropriate response as far as the process & factors that provide data that SMAW aluminum is not a sound process. Like some of the other " 'ol timers" here, we experienced the early days of aluminum welding & the associated "headaches"(porosity, slag inclusion, etc.) inherent with SMAW aluminum. The advent of MIG & TIG eliminated viturally all issues if the correct parameters are employed. Even back in my days ('50's), the best results were with O/A rather than SMAW.There is a vast amount of data available online if you do some simple searches. Here's a good start if you have not researched alum. SMAW: http://www.brazing.com/techguide/pro.../allumimum.aspI agree that your success would be interesting with photos provided & an in-depth explanation of your procedures..... "the proof of the pudding is in the eating"......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:Hey Steve,Ok....my bad...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:Ok we are gonna do it the way you guys like it. You know after posting on another thread I remember someone saying something to this tune.You can't weld aluminum dc- for thin aluminum. My response to that was .100 or better meaning unlimited.I was so wrong ! My Apologies I can really accept when I'm wrong.Looking around in the shop for a stack of aluminum plates, I found them. I went to the center of the stack pulled a couple, (these were cleaner) wiped it with MEK.Gave it a light brush before I welded. Got the old dusty Powcon smt 400 out (a boys toy )and set the welder to 125 amps got some crummy helium not the good stuff. The powcon is set to a scratch start tig. Used a 3/32 tungsten 2% thoriated gas set at 35. Took me what was a whole 17 sec. to weld this tee fillet. Just to find out that I was ultimately wrong.What I thought was .125 material turned out to be .090 Ha ha ha. After being in court all dayand coming back just to go play catch up in the shop. I was tired, I had to put a belt around my wrist just to get the hand steady. End of the day, just laid on one more weld. Just so I can show half you pretenders, It can be done! I wanted to go out and buy a new BB with video just so I can play a video of this process. I don't care how long anybody been welding but when you limit yourselves by closing the mind, its the end for you. Sorry to say half of you dont't now what your talking about when it come to gtaw.Its mostly bad info, but its fun here in my office to listen to those elect few go on and on and on and on.A few need to proof your posts.P.s.there was no burn thru. Good luck  I'm Done. you try it and let me know how you did.If I offended anybody my apologies. Good Luck Attached Images
Reply:I cut the end off to show complete weld with no burn thru.
Reply:Originally Posted by Spar-XBummer,I was hoping for something useful, 2 min. I cant get back.
Reply:How come the right side of the bead (as you're looking at it) looks so much different than the left side?First 1/3 of your bead (R to L) looks like you got virtually no bead at all.Looks to me like you were chasing filler so fast that you lost consistency in your timing.Last edited by Rojodiablo; 07-17-2010 at 01:53 AM.Reason: Making me earn it....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:This is the nice thing about being a novice. I can be called the fool, but be shown my failings to fix it.For others... "It is better to be silent and be thought the fool, than to speak and remove all doubt."Now I've got some questions.  Since you have now proven you can do it. That's the first proof I've seen.#1  Why do you have to use helium? As opposed to straight argon with AC.#2  If helium is so expensive, how many bottle fills does it take to make up the difference in cost of an AC vs. DC machine.  I am asking because most newbies are trying to get away with buying a cheap DC only machine and if the gas costs quite a bit more then they really aren't saving a thing in the long run.  This is assuming 1/4" and thinner aluminum will be welded.  I'd say 99% of what I do is 1/8" as an example.Sundown, feel free to chime in hear too.My name's not Jim....
Reply:Did you wire brush your weld when you finished?
Reply:Helium is the only gas that can be used in this process. My preference is ac for thinner aluminum.022 .032 .040 argon up to .100 helium/argon for .100 to.187 .250 and up helium.The gas question, consider where you live . The city or BFE, sure it gonna cost more if your gonna trek a single bottle across the desert, It's cheap for me I use a lot and it's readily available. Machine trade offs you would actually use less helium less light less time welding with this process.The aluminum is liquid as soon as you arc, so you better get your wheels moving when using this process. There no way around the machine point. Ac and DC go hand in hand your gonna need both processes for welding aluminum. This was done at the request of a couple of disenchants.HAAHHAVE A AWESOME DAY,Last edited by Rojodiablo; 07-17-2010 at 01:55 AM.Reason: Editing on a borrowed laptop sucks.
Reply:Yes I brushed the soot away after welding.
Reply:Boostin,Saw your question last night but wanted to wait for the OP to reply.Since he chose not to address your questions, I'll give you my feelings.In DC welding of aluminum it has been found that helium is required (vs argon) because the process requires the additional heat produced in the arc by a helium envelope.  This additional heat is what makes the process effective on thicker material but, at the same time is a distinct disadvantage when welding thinner material.Most of the posters who've commented, as I do, feel that the process is not the best way to weld thinner aluminum (less than 1/2").  Posters (Thermal and Billy Mac) who advocate this process are giving our newbie tig welders a mistaken impression that they can just pick up a cheap DC buzzbox and start welding aluminum.  Not happening for a multitude of reasons.Most of the DC machines we're talking about do not have a Hi-Freq capability.  Therefore, you're forced into a scratch start of the arc.  If you've done much aluminum, you'll know that it only takes a microsecond to contaminate your tungsten when it comes into contact with aluminum.  Some have used a "workaround" which involves starting the arc on a block/strip of copper and then carrying the arc over to the aluminum to be welded.  Not the easiest thing to do consistently.DC welding requires an extremely short/consistent arc length.  As shown in Thermal's photos, any arc variation shows up as inconsistency in the bead profile.  It is much more difficult for an inexperienced tigger to maintain this arc.   Also because the arc is shorter, you can expect to experience much more "dipping" resulting in contaminated tungstens.Because of the additional heat generated in a DC arc, the travel speed must be increased to compensate.  Most new tig welders cannot maintain the consistency required (forward movement and dipping of rod) at these higher travel speeds.  Thermal, who claims to have "used the process for years" could not even maintain consistency in the short bead he created.  The difficulty increases if you try to maintain a bead over a meaningful distance.  With thicker material, you have more of a "heat sink" to deal with and the process becomes more viable.  Also the higher travel speed and hotter arc can be beneficial in achieving addititional penetration and a reduced HAZ (faster travel).DC- welding of aluminum provides NO cleaning effect on the base material (done by the DC+ cycle in AC welding).  This means that the base material must be cleaner for a DC weld than it needs to be for an AC weld.  If you notice the photo Thermal posted, the right side of the bead (where he started) appears to have a degree of porosity in the bead.  This is because the material was still cold there and it did not go away until heat built up in the base material.  With thicker material this is less of an issue as it takes longer to get the initial puddle started.If you study Thermal's "cut" coupon, you'll notice good penetration.  You'll also see that bead was very close to "blowing thru" on the vertical member.  I'm betting that if you did a series of "cuts" (say every inch or so), you would see tremendous variation in the depth of penetration in the bead.  This is based on the inconsistency in the size of the bead we can see on the surface.Those "inconsistent dimes" that we see in the photo, are not good and create additional (potential failure) areas in any weld bead.People who "jump up and scream about how great DC- welding is", to me, are the guys who haven't kept up with the times and don't accept the fact that there are better, more advanced, and easier to teach techniques to accomplish the same thing (only better).  The first step came with the introduction of the square wave technology and the incorportation of the balance control.  This gave welders  the capablilty to adjust the arc (percent of DC- and DC+) to achieve a desired result.  With today's inverters (say a Dynasty 350/700) an experienced tigger can set his machine to achieve the exact degree of DC- he needs to get the best result (penetration or cleaning).  Some guys, I guess, would prefer to still drive around in a 54 pickup with less hauling capability and burning more gas.While on the subject of gas, it should be noted that DC- welding with helium is also a much more expensive process than doing the same task with an AC machine with argon.  Due to the specific gravity (lighter than air) of helium, increased flow rates must be employed to maintain a covering envelope.  Generally speaking this flow rate is 2 to 3 times that of argon.  Here in VA, helium costs me (per cu ft), about 2.5 times as much as argon.  If you multiply the flow rate times the cost of the gas itself, (2 x 2.5 = 5), you'll see that your covering gas costs to produce a weld is almost 5 times as much.  Your actual weld time will be slightly less (faster travel) but your pre/post flow will be the same.Actually, I'm very happy that Thermal posted up photos of his work.  Really made it easier to explain my postion.  It also gave me additional assurances that I'm not likely to lose any aluminum tig work to a Mexican using outdated equipment.I could take an inexperienced tigger, put him on a quality machine (Sync or Dynasty for instance), and have him producing better, stronger, more cosmetically appealing AC welds on aluminum in two weeks than what I see in those photos.  And Mr. Thermal "has been welding aluminum for years".Yea, Thermal demonstrated that he can weld .10 thickness aluminum with DC-, but I ask the question, WHY would you want to?Last edited by Rojodiablo; 07-17-2010 at 01:58 AM.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:Thanks for the reply Sundown.  So just looking at the cost of gas, I know I pay $40 per fill of my 125 argon bottle, if I was to switch to helium and weld DC instead of AC, it would cost me about an extra $160 per fill.  Let's say I fill my bottles 6 times a year.  That's $960 per year extra it costs for gas.  In one year, maybe two, I could easily justify paying more for an AC/DC welder.My name's not Jim....
Reply:Originally Posted by thermalfusioneng.Yea, this Wetback better do it on his invertec v205t or his invertec v311t  which ever you want....  ...Its .090! WAA...