Anodized Aluminum

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Does anyone know if it's possible to weld 1-1/2" sch 40 anodized aluminum pipe using a 302 Miller Trailblazer with an HD-251 HF box?
Reply:I don't see why not. There are quite a few threads on welding anodized aluminum. Search "Boat towers" or "Anodized aluminum" and you will see the pros and cons of some different process' . I weld some anodized towers and railings. If you can, grind off a little of the anodizing. If not, set up for more cleaning on the AC balance wavereduce the downslope to 0, and hit it with quite a bit of amps.(175-225) You need a lot of amps to basically blow the anodizing off to the sides as you start the puddle. Move quickly. That's about the best I can do for you, other than the obvious: Just try it on a scrap piece, and see what happens!!!And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Thanks Rojodiablo! The reason I ask is because that's the only machine I have now capable of doing this. A friend of mine who is set up to do this kind of work let me try my hand at it with his equipment and my welds turned out pretty good. I have a 10" miter saw with a non-ferrous cutting blade. Could I use this to cut the pipe? I just can't seem to find a clamp designed to secure pipe to a miter saw base. Thanks for all your help!
Reply:The saw will cut it just fine. Once again, I'll let you in on another sin of aluminum pipe fitting: Just get the cuts close, you don't have to be as close as with SS. The bead will be larger, so just add extra filler to cover the small gaps. I use a non-ferrous blade on my skilsaw to do rips on aluminum sheet, upto 1/2" in thickness. It is the only thing faster than a plasma cutter!! Makes a lot of noise, throws some chips....but it works great. A little blade wax can really help with galling and binding. Worst thing will be aluminum sticking to the blade body, not to the teeth.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Clean all the anodize from the weld joint. Anodize is just a layer of oxide on the surface of the material. This oxide melts at a temperature higher than that of the base metal. Because of this, solid pieces of oxide will remain in the molten weld puddle. When the puddle solidifies the solid pieces of oxide will be trapped in the puddle and can cause brittleness in the final weld.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:Reddoggoose,I agree with what you're saying (as I do with most of your posts-very well informed) however, in practice, few welders will mechanically remove all anodizing from the material to be welded.The larger marine tower builders (to include Pipewelders--largest tower builders in the world) do not prep their material to degree you would expect.  To remove all anodizing from the base metal would more than double the time required to fabricate a full tower.  The solution, although somewhat of a compromise, is to simply run hot and run fast.  The extra heat seems to do an acceptable job of "burning off" the anodizing.  I know of almost no failures attributable to not preping properly.  The failures that do occur are due to "bad welds" or improper design, not improper preparation.I have seen many more failures attributible to multiple pass welds, than I have as a result of not properly removing the anodizing.  These failures occur not in the weld, but in the HAZ immediately adjacent to the weld.Just my .02Syncro 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:I agree in practice few welders do remove the oxide, however that does not make it right. With oxides the brittleness may not be enough to cause failure, however that is dependent on the type of loading and forces applied to the weld metal. For example when under going a bend test to check ductility, you will be more likely to fail if the oxides are not removed.The failures in the HAZ are most likely due to over precipitationing the aluminum. Some aluminums are sensitive to heating such as 60601T-6, which will lose typically 1/3 to 1/2 of its stength due to over precipitation of the material. By adding extra heat to burn off the oxides, more damage is being caused to the basemetal due to increased heat input, and over precipitation of the material will be worsened increasing the likely hood of failure.Thank you for the compliment on my posts.Last edited by reddoggoose; 08-24-2007 at 12:38 PM.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:Melting point of aluminum oxide is ~ 3720 F.Melting point of common aluminum alloys is ~ 1200 F.The anodizing is pretty much aluminum oxide.  Clean it off before welding.Oh, and the anodizing is not all that electrically conductive either.  So your weld parameters are all screwed up from that aspect of the oxides as well.You can't weld paint, or grease, or mill scale, or rust, or anodizing.  You weld METAL.  Anodizing or rust or mill scale are not metal.Also, the anodizing layer tends to contain water within it in the form of hydrated aluminum oxides or traps some water or water vapor or grease/oil, which are all sources of hydrogen.  Hydrogen in welds is BAD-BAD-BAD.And welding a heat-treated aluminum alloy will ALWAYS change the strength.  Some times just a bit, sometimes by 50% or more.  Welding 60661-T6 with 4043 will drop the yield strength from an original 40 ksi down to 18 ksi, using 5356 drops it down to 19 ksi.
Reply:Originally Posted by reddoggooseClean all the anodize from the weld joint. Anodize is just a layer of oxide on the surface of the material. This oxide melts at a temperature higher than that of the base metal. Because of this, solid pieces of oxide will remain in the molten weld puddle. When the puddle solidifies the solid pieces of oxide will be trapped in the puddle and can cause brittleness in the final weld.
Reply:Originally Posted by RojodiabloActually, the oxides and anodizing are pushed to the outside edges of the weld, and float on the top, like many other impurities. The weld itself is good, and solid. There are 2 other guys here on the forum who do it all day for a living on boat towers. I do the aluminum only part of the time; I do more SS on boats. But there is a member here who works for pipefitters, and he explained it very well. You need to set up for more cleaning, and a lower freq. if you have the option. On my own boat, the tower never fails at the HAZ, or the welds. It always fractures wherever the tower flexes the most. I have had it repaired like 4 times already! It is all 6061, t-6 pipe, sched. 40, anodized. Miller went to pipefitters, and there is an article on Millerwelds.com about the company welding through the anodizing. They stress tested and x rayed it, it was solid, and Miller acknowledged that though it was a different than standard method, it was totally acceptable.
Reply:You will also get better looking welds if you remove all the oxide.  The difference is quite surprising!Me!
Reply:Originally Posted by reddoggooseI'll see it before I believe it.
Reply:I dont need to look up anything. If you don't want to believe me then go to the AWS forum and post the question. Welders, engineers, and inspectors from all over the world are on that web site and they will say the same thing. You don't weld over anodize. ANODIZE get it?. The material for these towers are not coming in anodized. If it gets anodized, it is after the welding is done. What you are welding on is the thin passive oxide, anodize on a part is too dirty to even begin to weld. The passive oxide layer can be removed by the DCEN current of the sine wave when tig welding. Anodizing is done purposefully, people pay to have it done to help stop corrosion, why would you anodize before welding. The anodize would be destroyed during welding and have to be reanodized before shipping.Last edited by reddoggoose; 08-25-2007 at 12:21 AM.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:http://www.weldingweb.com/vbb/showthread.php?t=1773, http://www.weldingweb.com/vbb/showthread...dized+aluminum It's obvious you aren't understanding that we weld RIGHT THROUGH the anodized every day. Or, in my case, once every month.....Honestly. Not trying to be a bitch with you, just telling you that yes, every stick of aluminum I get from Morse is anodized. And I burn right through the stuff with high amps, lots of cleaning, and a freq. in the 60-70 range. I set my welder to ramp up in .1 second to full tilt. I weld thisd stuff at 180amps-200. I set the downslope to 0, that way, the instant the arc stops, the puddle freezes, and the burnt anodize is on the outer edges. Yes, the anodizing is gone from the welded areas. It is just how it is done. Imagine the size of dunktank you'd need for a 2 stage tower on a 65' Mikkelsen yacht.... there is no tank big enough to dunk it. I'll get some pics of my boat tower welds tomorrow, when the light is good.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:I still have a hard time believing that these welds will pass an AWS bend test. No disrespect to you, but I'll believe those welds aren't brittle when I can do the welding and destructive testing on them myself, and have them pass.Last edited by reddoggoose; 08-25-2007 at 12:49 AM.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:Reddoggoose,You're talking theory, specs, and what would be ideal in a perfect world.  As I said before, you have textbooks which will back up your position.From some of your comments, I don't think you really understand how boat towers are fabricatad in the "real world".  First, the material, 6061-T6 comes to the fabricator already anodized.  As was stated, there's no vat large enough to dip a full tower for a 65' Sportfisherman.  The material is then bent, cut, fitted as applicable.  It is then welded.  Basically, as stated before, you weld hot (190-210A) and fast.  This minimizes the HAZ.  Welds are then generally spot painted with an aluminum paint (Rustoleum, etc) to provide further weather protection.  To mechanically remove all anodizing would remove protection the aluminum needs to survive in the marine environment.Many small boat aluminum fabricators (T-Tops, Radar Arches, Rocket Launchers, etc) use 4043 filler because they feel it "works better".  For higher stress applications many quality fabricators use 5356 filler because of the additional strength (even though the material will not be re-anodized).These are industry accepted practices which have been utilized for the last 25 years.  As I stated before, the failures that occur are generally due to inexperienced welders (bad welds) or poor design not because the anodizing contaminated the weld.  In reality, most tower failures are attributable to excessive flexing of the boat itself.  Generally speaking, the towers are more rigid than the platforms they're bolted to.  For those in the industry, they know which boat manufacturers I'm talking about.On a 65' Full Tower Sportfisherman, you're talking about 200-300 welds.  Just not practical to do the prep you're talking about.  Not going to happen!!!In the end, what we're talking about theory vs what has proven to work in the "real" world.  If it didn't work, the fabricators would have had to change the way they do things long ago.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:So far all I hear is this is how its always been done. All the failures are in the tubes themselves and not the welds. All this proves to me is that the design is inadequate and that it is the weakest link. What I want to know is what testing has been done to prove that the welds meet base metal mechanical properties.  Are you following any particluar welding code?Last edited by reddoggoose; 08-25-2007 at 03:08 PM.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:Originally Posted by reddoggooseSo far all I hear is this is how its always been done. All the failures are in the tubes themselves and not the welds. All this proves to me is that the design is inadequate and that it is the weakest link. What I want to know is what testing has been done to prove that the welds meet base metal mechanical properties.  Are you following any particluar welding code?
Reply:Reddoggoose,In response, everytime a 50-65' Sportfisherman clears the inlet and heads offshore 100+ miles in 8-12' seas, it's tower is subjected to "destructive testing".  Tournament sportfishing is a brutal testing ground for equipment.Been there, done that, more times than I care to count.Been a dealer for Bertram, Hatteras, Viking, Egg Harbor, Blackfin, Buddy Davis, and others.  Anyone familiar with sportfishing will understand where I'm coming from.  Your comment about "how we've always done it that way" was correct.  If it taint broke, don't try to fix 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:Exceptions to every rule.Anything worth doing is worth doing RIGHT
Reply:So I guess what your telling me is that you have no idea exactly what the mechanical properties of the welds are. No real testing has been performed to determine if the welds even come close to base metal properties. Apparenty no code is being followed. Testing by running the boat out in the open still doesn't prove that the welds meet any kind of criteria other than your specific application. So all you can really say is that welding over anodize will make a weld strong enough to hold up to stresses found in your specific environment. You really have no idea of just how stong the weld is outside of that because you have never tested or measured any mechanical testing. So to respond to a post, where you have no idea just what kind of strength or ductility is required, by telling someone to leave the anodize on (when it is uniformly under stood by the welding communinty to remove anodize prior to welding, especially in any code application) seems very ignorant to me. For all you know that weld could be stresses to it's UTS where any oxides in the weld could cause failure. Still waiting to hear what code you are welding to. You mention that it's better for the tower to flex than fall on people. I would think in such a situation that at least the AWS aluminum structural code would be followed and that the welders on the job would be aware of it.As far as Rojo funny man coment about only knowing what the manual say, I thought I'll let you know that the manual doesn't say exactly when or how the welds will fail. Thats what the mechanical testing is for... and apparently he has neither.  But maybe he is right, I guess we should let the guys in the aerospace industry know that it is no longer necessary to use pickling to remove oxides, because the guys that build boat towers say its OK not too. That will make me feel much better next time I'm 30,000 feet above the ground.Last edited by reddoggoose; 08-26-2007 at 12:15 AM.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:Reddoggoose,I just went back and read this entire thread.Somehow I just didn't get the idea the OP was preparing to do an aerospace weld to a specified code requirement.How do you determine that "all" the oxides from anodizing have been removed by prepping?  Is it 10 swipes with the SS brush or is it 20?  What does the book say?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 reddoggoose So all you can really say is that welding over anodize will make a weld strong enough to hold up to stresses found in your specific environment. You really have no idea of just how stong the weld is outside of that because you have never tested or measured any mechanical testing.Still waiting to hear what code you are welding to. You mention that it's better for the tower to flex than fall on people. I would think in such a situation that at least the AWS aluminum structural code would be followed and that the welders on the job would be aware of it.As far as Rojo funny man coment about only knowing what the manual say, I thought I'll let you know that the manual doesn't say exactly when or how the welds will fail. Thats what the mechanical testing is for... and apparently he has neither.
Reply:Here are some decent photos of welds on anodized tube I took today. Some of these are gussets, or replaced sections I have done over the last 5 or so years. You can clearly see how the anodizing gets pushed to the outside edge of the weld; the weld itself is good. The photos were taken in macro, lens about 6" from tubing. A little optical zoom, no digital zoom (it tends to pixillate too much).Last edited by ZTFab; 08-26-2007 at 10:13 AM.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Originally Posted by SundownIIIReddoggoose,I just went back and read this entire thread.Somehow I just didn't get the idea the OP was preparing to do an aerospace weld to a specified code requirement.How do you determine that "all" the oxides from anodizing have been removed by prepping?  Is it 10 swipes with the SS brush or is it 20?  What does the book say?reddog....I can see your point but here's my 2 cents....What you're stating is that we shouldn't say that welding over anodized aluminum is acceptable in any application because one person down the line might make a bad decision and not do enough research before attempting a potentially dangerous project.IMO, if someone is performing a task or building a project that is so critical then it is the responsibility of that person to determine what is acceptable. Just because they were told something or read it on the internet doesn't mean that is specific to their project. They should do more research.Knowing that welding over anodizing can be done will allow a person to do further testing on the weldment to assure it's use in their application. If they take that information at face value and don't do any further research, then that is their fault.Stating what we know can be done and what has been done doesn't give everybody the green light to use those methods in every facet of every project.I'm so sick and tired of people saying that "you can say or do that because someone else might take it the wrong way".Whatever happened to accountability?Should automakers stop making cars because some people drive drunk?Should gun makers stop making guns because some people use them in robberies?BTW, I know that welding over anodizing can be done but I never do it. I hate the stuff and always try to remove it completely.- PaulLast edited by ZTFab; 08-26-2007 at 11:15 AM.http://all-a-cart.comWelding Cart Kits and accessories
Reply:ZTFabI  agree with you almost completely. Everybody needs to be acccountable for the work they do and the manner in which it is performed. That is why welding codes dictate who is responsible for performing mechanical testing of PQR's and WPS's. What bothers me is when people make recommendations without a full understanding of the situation. Apparently the boat tower industry is OK with not removing anodize. Does this mean that it is now acceptable for structual aluminum industry to follow suit??? Fact is that most people who come to this website are not going to perform mechanical testing before doing a job, most people on this website may not even weld to any particular codes. So maybe when making recommendations it would be better to be on the safe side. Oxides can give brittle welds and that is fact. It's not just me who says this, but the entire aluminum industry. This information has been based on decades of testing and practice, its not something that I just made up.The following information is taken directly from Alco Tek, I assume that we can all at least believe that Alco Tek knows something about aluminum."The general melting temperature of aluminum alloys is around 1,2000F while the melting temperature of aluminum oxides is 3,7000F. Aluminum oxide is not melted during the welding process and if it is present to an excessive degree, it can easily cause lack of fusion and oxide inclusion type defects. With this in mind, we present the following guidelines for the proper storage, joint preparation, cleaning, and welding of aluminum"My point is that the boat tower guys have done no formal testing to prove that the welding methods they are recommending have none of the defects previoulsy named. And yes, I agree,  if guns kill people, then spoons made Rosie O'Donell fat.Last edited by reddoggoose; 08-26-2007 at 01:25 PM.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:Originally Posted by reddoggoose...And yes, I agree,  if guns kill people, then spoons made Rosie O'Donell fat.
Reply:Originally Posted by reddoggooseSo far all I hear is this is how its always been done. All the failures are in the tubes themselves and not the welds. All this proves to me is that the design is inadequate and that it is the weakest link. What I want to know is what testing has been done to prove that the welds meet base metal mechanical properties.  Are you following any particluar welding code?
Reply:BWS29128- that was the most convoluted post I have ever read. I think I love you!!!And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Originally Posted by reddoggooseMy point exactly. You have no idea what the application is. All you know is that welding over oxides works for your application. Point of all this, is just because it worked in your specific application does that mean that you can just weld over anodize anytime you want to.
Reply:Originally Posted by BWS29128Who frikkin' cares what the application is...that was NOT the original question!The original question was:The answer was a very clear and resounding "YES IT IS POSSIBLE"!!!Dadgummit reddoggoose......you're swimming upstream here....Can it be done? Yes. End of SNAFU!
Reply:Originally Posted by Rojodiablo BWS29128- that was the most convoluted post I have ever read. I think I love you!!!
Reply:STOP THIS RIGHT NOW!!!! ...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:Originally Posted by zapsterJust as long as you grind out the annodization first...  ...zap!
Reply:Well I got to hand it to you, that sure was a lot of blabber about nothing.However, I think you are right that we must have a failure to communicate, because nothing here references or even mentions any thing regarding PQR's on aluminum stuctures. My question regarding destructive testing still has not been answered, and I'm tired of asking it. So far the only codes you have mentioned are the structural steel code, the bridge code, and reinforcing steel code. None of which deal with welded aluminum structures, and to top it off those sections are in regards to NDE procedures. I have not said one thing regarding NDE of boat towers now have I? You do know that there is a difference between NDE and destructive testing don't you? Here's hint, in destructive testing the joint is DESTROYED. Nondestructive examination it is NOT. See the difference??? No No boys, nice try but it ain't going to fly with me. If your contract documents allow you to walk outside the code, good for you, I don't care. My point is that you have failed to mention anything regarding PQR's for your application, yet are willing to tell unexperienced people that your procedures are valid. What's almost as unsettling to me is that in 2 days of debate the welders who are supposed to be working to this code could not even tell me which code it is.To tell you the truth, it would make little difference to me now any how. While cleaning base material is not required by the aluminum code, though strongly recommended by industy. You guys have spewed so much B.S., that even if you put the acutal PQR in my hand that said your joint met code requirements, I wouldn't trust it.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:Originally Posted by zapsterSTOP THIS RIGHT NOW!!!! ...zap!
Reply:Originally Posted by reddoggooseWell I got to hand it to you, that sure was a lot of blabber about nothing.However, I think you are right that we must have a failure to communicate, because nothing here references or even mentions any thing regarding PQR's on aluminum stuctures. My question regarding destructive testing still has not been answered, and I'm tired of asking it. So far the only codes you have mentioned are the structural steel code, the bridge code, and reinforcing steel code. None of which deal with welded aluminum structures, and to top it off those sections are in regards to NDE procedures. I have not said one thing regarding NDE of boat towers now have I? You do know that there is a difference between NDE and destructive testing don't you? Here's hint, in destructive testing the joint is DESTROYED. Nondestructive examination it is NOT. See the difference??? No No boys, nice try but it ain't going to fly with me. If your contract documents allow you to walk outside the code, good for you, I don't care. My point is that you have failed to mention anything regarding PQR's for your application, yet are willing to tell unexperienced people that your procedures are valid. What's almost as unsettling to me is that in 2 days of debate the welders who are supposed to be working to this code could not even tell me which code it is.To tell you the truth, it would make little difference to me now any how. While cleaning base material is not required by the aluminum code, though strongly recommended by industy. You guys have spewed so much B.S., that even if you put the acutal PQR in my hand that said your joint met code requirements, I wouldn't trust it.
Reply:And you, my dear friend have still not answered his question either.As far as I'm concerned if a welding procedure cannot consistently pass a code destructive test then NO that procedure is NOT possible. AWS codes require destructive testing, especially the aluminum code as there are not prequlified joints in that particular code. Maybe you should spend less time blabbering and more time learning. Apparently it is you who has no understanding.I find it hilarious that you accuse me of stealing this thread, when the best answers you can give are personal attacks. That's allright don't bother me, while my skin isn't as thick as that anodize you keep burning into those welds, it still doesn't let ignorant opionions get to me. If you are so bright you would know that sanding, and etching are both code approved ways for aluminum base metal preparation.P.S.  It's not NDM its NDE, and you are the one who brought it into the thread.Last edited by reddoggoose; 08-27-2007 at 11:18 PM.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:Fellas, fellas...take it easy. Roj, BWS and reddog all go sit in a corner for a few minutes and take a deep breath. We are WAY off topic here. If you guys choose to continue arguing, take it to PM. Personal attacks on education, skill or reading, writing, 'rithmatic aren't taken kindly here. Please refrain from using such statements. Thanks. By the way - has anyone seen the Brooke Burke picture I posted?John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Reddoggoose,Let me say this and then I'll shut up.Marine tower fabrication is as much an art form as it is AWS code welding.Fabricators use a process (which has been described in detail) to fabricate their towers.  If their towers were to break on a regular basis, due to welding failures, they would be out of business.We're talking about tuna towers, some upwards of 40' tall, carrying human loads.  If there was a continuing problem with the welds, which could cause injury or loss of life, you can bet the insurance companies would require that the fabricators follow a different procedure.  That has not been the case.We're just trying to explain what's done in a particular industry.  Not nuclear, not aerospace, but marine fabrication.THE ENDSyncro 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 reddoggooseWell I got to hand it to you, that sure was a lot of blabber about nothing. You do know that there is a difference between NDE and destructive testing don't you? Here's hint, in destructive testing the joint is DESTROYED. Nondestructive examination it is NOT. See the difference??? No No boys, nice try but it ain't going to fly with me.
Reply:I give up. He says it's not possible when someone posted pictures showing him. Isn't that sorta like saying it's impossible to go to the moon when someone's already done it?  Oh well...it's 5:01am and I've got some anodizing I need to go burn away.
Reply:I find it incredibly interesting to learn that the tuna tower industry regularly welds anodized aluminum.  This goes totally against the common industry logic and published welding literature, that oxide should be removed prior to welding.I think this is very ingenious!The tuna tower guys had a welding problem, they broke the rules and found developed a viable welding method for their application.The lesson here, don't be so damn stuck in your ways, keep an open mind, you may learn something that you can use someday.By the way, here are past posts on this subject.http://www.weldingweb.com/vbb/showthread.php?t=1773http://www.weldingweb.com/vbb/showthread.php?t=7237http://www.weldingweb.com/vbb/showthread...dized+aluminumLike I said before, I'd like to see a comparison of mechanical properties for anodized vs non-anodized welds.