welding anodized aluminum

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Can aluminum that has been anodized be welded? Does it need to be ground off or can it not be welded at all?
Reply:yes, it can be welded, do not take the anodized off just wipe it down with acetone and use 5356 rod. a/c about 170 amps tig.make one weld around the pipe then bump weld over you're weld for a second time. real trickey. hope that helps you out.
Reply:The coating is very thin, but should to be removed in the area you intend to weld. If you need to re-anodize a 53XX filler would be needed.MattLast edited by Matt_Maguire; 06-29-2010 at 08:12 PM.
Reply:emwelding,Did I read your post correctly?  Are you really suggesting a double pass weld on anodized tubing?  I hope to heck that's not what you're saying.You use the term "bump weld" very casually.  Have you ever done this weld yourself?  I think if you do the weld yourself, you'll find you're a little light on the amps.  If you've already welded a bead aroung the tubing (not going to happen with normal tig technique), why would you go over it with a bump weld?Bump welding is a process that's taught.  Difficult to describe the timing.  Best to learn at the hands of an experienced tig welder.And, YES.  Anodized aluminum can be tig welded WITHOUT removing the anodized coating.  It's done every day in marine fabrication.  I can't imagine building a tuna tower where every weld postion would have the anodizing removed.  First it'd be way too time consuming and second you would loose the benefit of anodizing in the first place.Finished beads are generally painted over with silver rustoleum to provide a degree of protection from oxidation.Damn. I hate it when posters have just enough information to be dangerous.Slim Jim,Sorry.  Just get a little ticked when I see that type response.  Double pass welds on aluminum tubing are to be avoided if at all possible.  This actually, is what makes repairing marine fabrications so difficult.  You're almost always having to deal with a double pass weld which causes problems with cracking in the HAZ.Now, tell me what you need to weld that's anodized.  What your tig experience is, and what machine you have available to weld with.  Wimpy tig welders don't have the ba11s for bump welding.  A sync 250 is kinda an entry level machine if you have much welding to do.  You'll also need an on/off button for remote control (not a finger tip remote, but an on/off remote).Last edited by SundownIII; 06-29-2010 at 10:03 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:Hey Sundown?   I don't do a lot of Al, and often when I do I'm not pleased with the resulting look (especially with the hard filler). But when you do a lot of finish work you look at things harder I think.On most joints (if I can) I'll pull a shallow groove with a clean file and scratch with a very stiff SS plater's brush and go. But I'll always try to start with a clean aluminum surface.Have you got a photo of a "bump weld"? I'm curious.The folks not far from here make a pretty good boat all MIG welded;http://www.oquawkaboats.com/Some look more like a barge than a boat though, they're tough!Matt
Reply:Sundown, I'm going to be making and a oil line manifold for a dry sump race car motor.  Need to know if I can weld a an fitting that has been anodized blue to the tubing for the manifold. If the color gets messed up from the heat that is no big deal. Doesn't need to look show quality.  And ill be using a Lincoln precision tig275.
Reply:Slim Jim,For something like that, sand/grind the anodizing off before you weld.Matt,I'll look around and see if I can find some pictures.  I don't normally take pictures of customers work.  Some of my owners are a little sensitive about their boats.If you're interested though, you may want to do a search on "Bump Welding Anodized Aluminum".  I did a full writeup on the process a few years back.  Process was actually developed by PipeWelders, Inc. in Ft. Lauderdale, FL.  The son of the owner of the company (Edison Irving) taught me the process about 20 years ago.  Ed was running the PipeWelders facility at Cape May, NJ at the time.When I get some time, I'll try to find a link.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 SundownIIIMatt,I'll look around and see if I can find some pictures.  I don't normally take pictures of customers work.  Some of my owners are a little sensitive about their boats.If you're interested though, you may want to do a search on "Bump Welding Anodized Aluminum".  I did a full writeup on the process a few years back.  Process was actually developed by PipeWelders, Inc. in Ft. Lauderdale, FL.  The son of the owner of the company (Edison Irving) taught me the process about 20 years ago.  Ed was running the PipeWelders facility at Cape May, NJ at the time.When I get some time, I'll try to find a link.
Reply:K thanks. Ill post a pic when I'm done.
Reply:Nope can't weld it, lolNo need to remove the finish on the clear, I'm not sure if the color makes any difference. All I do is cut it and weld, works fine, just minor impurities from the anodizing burning off. we paint over the welds to protect them, rustoleum aluminum is an exact match.If you cannot convince them, confuse them.         Harry S Truman
Reply:Originally Posted by SundownIIIemwelding,Did I read your post correctly?  Are you really suggesting a double pass weld on anodized tubing?  I hope to heck that's not what you're saying.You use the term "bump weld" very casually.  Have you ever done this weld yourself?  I think if you do the weld yourself, you'll find you're a little light on the amps.  If you've already welded a bead aroung the tubing (not going to happen with normal tig technique), why would you go over it with a bump weld?Bump welding is a process that's taught.  Difficult to describe the timing.  Best to learn at the hands of an experienced tig welder.And, YES.  Anodized aluminum can be tig welded WITHOUT removing the anodized coating.  It's done every day in marine fabrication.  I can't imagine building a tuna tower where every weld postion would have the anodizing removed.  First it'd be way too time consuming and second you would loose the benefit of anodizing in the first place.Finished beads are generally painted over with silver rustoleum to provide a degree of protection from oxidation.Damn. I hate it when posters have just enough information to be dangerous.Slim Jim,Sorry.  Just get a little ticked when I see that type response.  Double pass welds on aluminum tubing are to be avoided if at all possible.  This actually, is what makes repairing marine fabrications so difficult.  You're almost always having to deal with a double pass weld which causes problems with cracking in the HAZ.Now, tell me what you need to weld that's anodized.  What your tig experience is, and what machine you have available to weld with.  Wimpy tig welders don't have the ba11s for bump welding.  A sync 250 is kinda an entry level machine if you have much welding to do.  You'll also need an on/off button for remote control (not a finger tip remote, but an on/off remote).
Reply:Originally Posted by Matt_MaguireCool, I'll give Google a try, thanks.Matt
Reply:Originally Posted by Top GunA micro switch off a plasma cutter works good for the switch
Reply:Top Gun,Which location for PipeWelders did you work out of?  SR 84 in Lauderdale?As you probably remember, PipeWelders grew considerably during the 80's.By 1987 they had locations in Fl, NC, NJ and one on the Gulf if I'm not mistaken.Ed was running the Cape May facility at the Canyon Club when I met him.  I was a Bertram dealer at the time (VA/MD) and he did most of my major tower work.  PW's also had a facility at Southport, NC., but Cape May worked better for me.If you started at PipeWelders you got some great training in welding and fabrication.  They kinda set the bar by which everyone else was measured.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 SundownIII...When I get some time, I'll try to find a link.
Reply:Bump welding, I gave it a look and have a question.This looks similar to welding Stellite 6 on steel using 3/16" or 1/4" bare rod in technique. But with Stellite it's all settings, trust and instinct because you aren't really working with a puddle using a tig.Is there a visual indication on the button press and then dip? Or is it just timing and experience. I can't remember trying to just blow through the rod with power using hard wire aluminum, but it doesn't sound like a very smart plan.Thanks in advanceMatt
Reply:sundown,                                                                                                                                                                                                                                                                     Lets start. sorry i may have ticked you off. just trying to explain to the man that anodized welding can be done. since I own a marine fabrication business I do alot of brushed and bright dip anodized aluminum, and have been for many years, Towers,T-tops,ladders,swimplatforms,etc.                                                                                                    I have never,ever had one  my welds fail. I run my Miller Trailblazer at 170 amps,run one bead around the pipe to get hot and then bump weld the second pass,yes i have a on-off button on my torch. yes it takes control not to overheat the pipe. many years of experience has given me the ability to do so. You can see my work on many manufactured boats. Again sorry i may have ticked you off. By the way if you go to the 'lets see you're rigs' you will see mine its the Toterhome that says Elite Marine Welding and Fabrication on the side of it.
Reply:People always talk about cleaning the base metal prior to welding with acetone, wire bush, emery paper etc. The best way to clean aluminum is when using the TIG process is to run a fast dry wash without filler metal. The speed should be slow enough to watch the black sut looking film disapate out of the aluminum. This is cleaning your base metal. DO NOT WIRE BRUSH THIS OFF OR WIPE IT OFF AS YOU WILL CONTAMINATE THE BASE METAL AGAIN. You will notice that the filler metal will flow smoother and the weld will have a brighter shine  and leave as deposited.
Reply:Oh great! Now I have two or more things on the plate!I won't/can't play with the AL for some time cause I'm covered up. But I'm a complete sucker at the "howdiddy do dat" and "I gotta have that tool in the box".The descriptions I originally read about BumpWelding seemed to make sense, but did not describe if a puddle was actually developed first before adding filler. Also as Sundown indicated above preparation is very minimal if done at all.emwelding makes a pass and then later flows the filler. Is the first pass done sticking small wire into the puddle at an angle and rate fast enough to raise the bead center a lot? Then the second pass flows and drives the bead down quickly? Is this only done with 5% mag aluminum filler?LarryC runs a dry wash with the torch to break the oxides. I have an aluminum cleaner that when used helps the rod bite "NOW" but it's a real pain to brush on then wash off and weld within seconds. If the dry wash works well at all, I'm gonna feel stupid!Matt
Reply:Matt, I've been welding TIG aluminum since the 70's and this is the old school method of cleaning all TIG aluminum welding from cast to pipe or plate. This process can not be used with GMAW or SMAW. When the base material is properly cleaned you not see any of the oxidation as shown in some the pictures that are posted. Wish you the best of luck
Reply:emwelding,Like you, I've welded my fair share of anodized aluminum (bright and brushed) over the last 20 years or so.What I found objectionable in your original post was that it differed so much from the technique I was taught and is used by nearly every "quality marine fabricator" on the east coast.The bump welding technique for tig welding anodized aluminum was taught to me by Edison Irving, who's dad just happens to own PipeWelders, Inc, and whose company originally developed the process.  I'm pretty sure they know what they're doing.Edison (Ed) is the best marine fabricator/welder I have ever met.  Used to weld like he was born with a torch in his hand.  Also one of the smartest guys I've ever run into.  Almost total recall.  Ironically, he's no longer in the fabrication business.  When the market went south in the early 90's (luxury tax), Ed got out of the fabrication business and started a company called Strataglas.  They supply the "press polished" clear vinyl sheet used for boat enclosures (amonst many other uses).  If you ever get over to the Ft. Lauderdale or Miami boat shows ask any of the fabricators if they know Edison Irving.  They'll tell you Ed was the best in a highly competetive field.  In reality, PipeWelders developed many of the designs and techniques which today are considered standards of the industry.Going back to both your previous posts, I'll point out a few things which I found "different" from the way I was taught.First was the idea of running an "initial bead around the pipe".  That in itself is quite a trick.  Now exactly how you do that with anodized material?  The fact that this is quite difficult, if not impossible using standard tig processes, is why "bump welding" was developed in the first place.  If you've somehow developed a process to make this possible, I would love to hear about it.Second, any time you run a double pass (as you suggest), you're overstressing the base material in the HAZ and creating a brittle spot more likely to fail under load/stress.  That is one of the challenges of "bump welding" in that you only get one chance to "do it right".  90% of the repairs I do can be attributed to one of three things.  Bad design, Bad technique (overheating the weld). or double pass welds.In your second post you state that you're using a Trailblazer for aluminum marine fabrication.  That's a new one on me.  Originally we used the Miller 330 A/BP's, then later on we went to the Syncs, and now most everyone has moved to the inverters.I've never used a Trailblazer for tig welding anodized aluminum.  I've used one as a power source to feed a Dynasty, but that's about it.  How do you set the balance control on the Trailblazer?  How do you control your gas flow?  Do you use a separate pedal/fingertip remote control for making your "original pass" or are you doing that with the on/off switch also?  Just seems to be a "very primitave" way to go about the task of welding anodized material.Also, you mentioned that you were "bump welding" at about 170 A.  I find this to be very low.  I was taught and have found from experience that the process works best in the 195-205A range.  The thought here is that the "arc force" generated by the high amps "blasts" the oxides out of the way rather than relying on the AC+ cycle to "clean" the base material.  Not sure 170A generates the "force" to do the job.  Additionally, without a balance control (I normally run 7.5-8.0 on the Sync) you're getting less "force" from a balanced wave.What type cooler setup are you using on the Trailblazer?  I've known a few guys who did minor repair work with an air cooled torch, but I don't know any "fabricators" who don't use a water cooled torch.  The high amps employed in bump welding will overheat an air cooled torch in short order.From your postings, you seem to have been able to create a "new standard".  I would love to hear more about how you overcame these stated obstacles.  Always looking for a new way to "skin a cat".Last edited by SundownIII; 07-03-2010 at 04:10 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:Well half way through the project and got the anodized piece welded, i ended up grinding the anodize off. The blue on the rest of it ended up turning black. Ill put a post of the rest of the project in the pictures and projects section. Attached Images