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pitting in aluminum weld

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  • Whetstone
    started a topic pitting in aluminum weld

    pitting in aluminum weld

    Hello, I have been having a few issues with aluminum lately, the worst being pitting in the weld, that has been driving me nuts. All of these issues only happen with a newer welder that I bought. THe welder in question is a 250 Snycrowave (sn# lg480049l). T weld looks ok on the outside, a little grainy and dull, but the bead is filled will gas pockets that only come out when ground down. Material is 6061 or cast mold plate, I am using both 4043 and 5056 and have the same issues. thicknesses vary from 1/4 to up to 4" thick. some times I pre heat sometimes not. I have tried pure, thoriated and ceriated and have the same issues. I like to weld hot, but very my amps as needed with the pedal. Filler and base materials cleaned with acetone and SS brush or scotch brite pad. Attached is a picture of the pitting.

    I will try to make a sample tomorrow with more accurate info for amperage, material, cleaning, rod, ect with a before and after grinding.

  • Hardrock40
    replied
    this may or may not be of any use. I made the clipboard project the other day,

    This was a super sized one. I wanted the edges rounded smooth with a bead look.

    So I went around the whole thing 99% no filler, I was seeing pinholes develop behind the puddle as the arc was moved forward. I could let off the heat some and move back onto the pinholes and rewet it just a little then move forward easy and the pinholes would fill in.

    Like maybe not enough heat to start with or moving to fast for no filler. Porosity is a pain to stop or get away from but if it bad technique, I believe it can be controlled by dealing with it as it happens.

    Leave a comment:


  • spence648
    replied
    Water can get trapped in the aluminum oxide and cause hydrogen when you weld on it.

    Heres a couple more things ive found happening to me.
    1. Check to make sure your tungsten isnt bending. If u weld at too high of amps for the size ur tungsten can bend. Then the heat from it will melt ur filler before it gets gas coverage and put contamination into the weld. Usually when this happens u can see the black speckles come from the filler.

    2. Try a new torch head. I had the problem u are describing one time at work. I traced it down to the torch. Once i replaced that it went away. I think there was a small leak inside the head that was putting coolant in with the gas. It wasnt enough to drip but was messing up my welds.

    3. I know this is pry a dumb one but ive seen it alot. Make sure u have a clean tungsten. Ive seen people touch it then keep on welding. It will melt off and contaminate the weld. Once i touch anything the slightest bit i stop and resharpen. If u do this trust me u will get sick of sharpening and get real good at not touching your tungsten.

    Leave a comment:


  • 6g 7018
    replied
    when i weld cast aluminum i blacken the part with acetylene soot . light the torch with just the acetylene on do not turn the oxygen on wave the torch on the part should turn black then turn the oxygen on preheat the part the black will vanish when it hot enough then weld away learned from a old buck with a funny hat and moustache

    Leave a comment:


  • Gobysky
    replied
    pitting in aluminum weld

    Worth a try to compare. Thanks for the link.

    Leave a comment:


  • H80N
    replied
    Originally posted by Gobysky View Post
    I noticed he never mentioned cleaning with acetone. He talked about some cleaning agent made by LPS? Wonder where you can get that stuff.
    The stuff he mentions is LPS ZeroTri®Heavy-Duty Degreaser..

    http://www.lpslabs.com/product-details/597

    He just said it was a good one... there are many .... acetone being the most common..

    I do not believe he was excluding acetone...

    As far as locating a supplier...

    http://www.lpslabs.com/find-a-distributor
    Last edited by H80N; 09-17-2013, 07:33 AM.

    Leave a comment:


  • Gobysky
    replied
    Originally posted by H80N View Post
    Here is a MILLER video on the subject of "Aluminum Porosity"

    it's Causes and how to avoid/minimize it...

    http://www.youtube.com/watch?v=Yu3BtdERmFM

    By Tony Anderson, Head of Aluminum Technology Miller/ITW

    I noticed he never mentioned cleaning with acetone. He talked about some cleaning agent made by LPS? Wonder where you can get that stuff.

    Leave a comment:


  • dave powelson
    replied
    porosity in cast mold plate?

    Originally posted by Whetstone View Post
    Hello, I have been having a few issues with aluminum lately, the worst being pitting in the weld, that has been driving me nuts. All of these issues only happen with a newer welder that I bought. THe welder in question is a 250 Snycrowave (sn# lg480049l). T weld looks ok on the outside, a little grainy and dull, but the bead is filled will gas pockets that only come out when ground down. ........
    1-If you're watching the puddle in action--normally one can see porosity forming, bubbling, coming up thru and around the puddle.

    2-The cast mold plate pic you posted looks like classic--just below the parent mold surface--fine, casting porosity--inherent to the casting.
    In 'normal' AL castings--porosity is ever present. (High end, investment castings have limited to zip porosity.) Trying to boil out and fill myriad, scattered casting subsurface porosity is an exercise in futility.....if the goal is zero porosity after machining.

    3-If you're getting porosity on wrought AL, then it's time to consider the usual suspects.

    4-Grabbing whatever type of filler rod to weld whatever type of AL
    can create other problems you don't need. Suggest studying what Alcotech recommends--despite the recco's of board pundits.

    5-Ditto the previous comments on preheating.

    Leave a comment:


  • Portable Welder
    replied
    Okay, So it sounds like your blaming the welder.

    The way your post reads is that you have welded these before without a problem and the only difference was the welder.

    Tig welding 4" thick aluminum should be difficult with a 250 amp welder, what does it measure the other way.
    If you preheat to 400 F. then Okay.

    You also mentioned that you were grinding on it which can cause contamination from the grinding wheel ( I'm not sure if they call broken off pieces of grinding wheel, HYDROGEN )

    Is there something that may have soaked into this particular casting like oil.

    What are they used for.

    Is your argon turned up to high.

    Is your cup the same size as the last one.

    Is your cup dirty.

    These are some possibilities.

    Leave a comment:


  • griff01
    replied
    Originally posted by Whetstone View Post
    I just did a little bit of goggleing, and it says that hydrogen comes from water vapor or grease. In the case of the mold plate it was definitely hot, especially by the time I got through half of it. I cleaned both the mold and rod with SS brush/scotch brite and acetone. The only place grease could be coming from is my gloves, which some times handle dirty steel. Generally I like to have two pairs of gloves, but am running on one pair now.

    While I am not blaming these issues on the welder I have never been able to make it produce satisfactory aluminum welds.

    attached are some recent welds that are also grainy and dull, but dont have the porosity issues (material is 1/4 x 2 6061)
    The pic you posted shows contamination in the bead. That is the "pepper" looking specs and the black soot at the start of the bead.

    Hydrogen can come from" just about" anything that isn't aluminum, argon or helium. Not just grease or water vapor.

    Griff

    ps
    Let us know how much argon is left in the bottle in use
    Last edited by griff01; 09-16-2013, 07:03 PM. Reason: ps

    Leave a comment:


  • griff01
    replied
    Originally posted by jrscgsr View Post
    I've had contaminated gas weld fine on steel, stainless ect but on aluminum it really gets nasty. Just change the bottle out and try another test piece.
    Same here.

    Griff

    Leave a comment:


  • Precision
    replied
    pitting in aluminum weld

    Awesome vid!!!!thx

    Leave a comment:


  • H80N
    replied
    Originally posted by Whetstone View Post
    Where would hydrogen be coming from? Not enough pre-heat?
    Here is a MILLER video on the subject of "Aluminum Porosity"

    it's Causes and how to avoid/minimize it...

    http://www.youtube.com/watch?v=Yu3BtdERmFM

    By Tony Anderson, Head of Aluminum Technology Miller/ITW
    Last edited by H80N; 09-17-2013, 05:51 AM.

    Leave a comment:


  • Whetstone
    replied
    I just did a little bit of goggleing, and it says that hydrogen comes from water vapor or grease. In the case of the mold plate it was definitely hot, especially by the time I got through half of it. I cleaned both the mold and rod with SS brush/scotch brite and acetone. The only place grease could be coming from is my gloves, which some times handle dirty steel. Generally I like to have two pairs of gloves, but am running on one pair now.

    While I am not blaming these issues on the welder I have never been able to make it produce satisfactory aluminum welds.

    attached are some recent welds that are also grainy and dull, but dont have the porosity issues (material is 1/4 x 2 6061)
    Attached Files

    Leave a comment:


  • jrscgsr
    replied
    I've had contaminated gas weld fine on steel, stainless ect but on aluminum it really gets nasty. Just change the bottle out and try another test piece.

    Leave a comment:

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