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Repair-welding cast aluminum

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  • VBI
    started a topic Repair-welding cast aluminum

    Repair-welding cast aluminum

    Lately I have had the opportunity to repair cast aluminum transmission cases for a local transmission shop that have cracks in them from minor to severe. When I get them, the cases have been degreased in a commercial quality 180 degree parts washer-cleaner.

    As clean as they seem to be they still have oil impregnated residue which as you know causes nothing but trouble while welding. I have successfully welded a number of cases however the best method I found involves weld grind, weld grind, etc., until a clean weld base is established for 100% pure build up.

    Has anyone found a more successful cleaning procedure where the impregnated oil can be drawn out of the case pores, prior to welding? Any ideas would be appreciated.

  • Blown S-10
    replied
    well, from what i've read, and you have said. i did a pretty good job of it. and next time i will do better. i'm going to get a piece of scrap to try out my 200dx on. just to see what the different is.

    thanx

    Leave a comment:


  • dandimand
    replied
    I do insurance vehicles all the time with broken trans and engine blocks etc.. . I have mainly used my aerowave for this with a balled zirc tungsten no preheat and hz around 40 and i use 4043 filler . i agree with the tinning as once you get first bead down then its easier from there . I have found that you may have to wash over the weld with just the torch at times if your getting lack of fusion due to crap in the base metal other than that Ive had no problems . I use straight argon. the reason i run my hz low as it puts more heat in the material so as then i dont need a preheat . Im just starting to use the dx 200 mobile for this and i have found the settings to be dif than the aerowave. ps if its a trans and there is oil good luck it has to be clean or it wont weld . when your welding if you see any black around your puddle it isnt clean enough . I use either flap wheels 60 grit or aluminum carbide burrs for cleaning. but before i use these i brake clean the crap out of it so as to not grind any dirt into the material . Ive also used wire with success as well .normally i use 4043 3/32 for tig or .035 4043 wire in the mig. If you have a smaller machine i would reccomend the preheat route as this will help alot .

    Leave a comment:


  • Blown S-10
    replied
    bringing back an old, but relavent, topic.

    i had to weld a trans case today. it had a 1/2" hole in it. i cleaned it really well. but, as you know, it had the pepper flakes in it. that wasn't the real problem. nor was the old lincoln i was using, plenty of power. the problem was, it leaked. i used solvent to check for a leak, and it leaked. my main problem was that i wasn't given enough time to do the job, and was missing a few tools(carbide die grinder, and wire brush). it turned out pretty good anyway.

    what no one has brought up. what filler to use ? i used 4043. but i have used(not on trans welds) a smoother flowing rod. but i don't remember the name of it. i was thinking it would make things go better ?

    Leave a comment:


  • philthewelder
    replied
    As mentioned above, preheating is the only way to go with cast aluminum. If you are using a torch to preheat make sure you keep the temp below 500 deg. Use a temp stick, or one method I was shown years ago is to blacken the weld area with carbon from lighting acetylene only. Then heat with a neutral flame until the carbon burns off. This will put the metal right at 500 or less deg. Preheating the aluminum will also require less amperage to weld.
    As everyone knows sometimes cast alum is just a pain so good luck!

    Leave a comment:


  • Paul Seaman
    replied
    Have no fear of her getting away from me. A year ago I thought I might lose her to cancer and the feeling was horrible, but it has given me a new focus on what is improtant.BTW the reason I was on this forum in the first place was I wanted to keep close while she was sick.

    Peace,

    Leave a comment:


  • VBI
    replied
    HAWK, I will abide by your advice and keep the wife #1.

    pjs, you are a lucky man, don’t let that one get away!

    Leave a comment:


  • Paul Seaman
    replied
    VBI:
    My wife placed the order for my mm210, and she was a driving force in me getting the D200DX. Some wifes are not as understanding as mine, so could I recomend flowers first .

    I have used the D300DX and you'll love it and the mm350p is the slickest mig I've ever seen. Fact is they are the only machines I would substitue for mine!

    Peace,

    Leave a comment:


  • HAWK
    replied
    VBI,

    One of each would be a sweet combo. It won't matter which machine is your number 1 or number 2 favorite, but better keep the wife number one!

    Leave a comment:


  • VBI
    replied
    I appreciate all the input concerning this thread. I now have to ‘demo’ two machines this spring because of this forum, 300DX, MM350P. Going to have to treat the wife a little extra nice!

    Thanks

    Leave a comment:


  • HAWK
    replied
    Rob,

    I did not have the luxury of such a great tool as this forum or even the internet when learning and working the art of welding. Looking back it was just as hard as I remember it. I am an active member here hoping to help some folks along in their welding by relating experiences and knowledge gained along the way. Most of all I am here because I enjoy it! Thank you for such kind words.

    The HAWK.

    Leave a comment:


  • rb455ho
    replied
    HAWK, I always enjoy reading your posts. You should write a book. I would certainly buy a copy.

    Leave a comment:


  • Blackplague
    replied
    The thing i like about the Frequency adjustment is

    Speed. I started out with a non-squarewave 330a/bp and would have to preheat, and even with that i would be waiting forever to get the puddle to start. Now that i own a dynasty, i can take a aluminum cylinder head out of 30 deg weather and get the puddle to start almost instantly and that is without preheating. {the bigger the HZ frequency, the quicker the heat, other benefits like HAWK says is arc shaping for control **

    No matter how clean you get a trans case you will always fight the poor quality aluminum that the case is casted with. They have a ton of zinc in them which makes them a little on the tough side to weld. The top of your weld bead will have what looks like pepper floating on top {really nothing you can do about it**.

    Since you have a transformer here is something to try. groove out the crack with an aluminum burr, then use a cleaner such as brake kleen, acetone, etc, wait till the cleaner air dries, then take a torch and with just the accetelene {spelling?** lit, carbon up {soot** the groove, then get the torch up and running with the oxygen and pass it up and down the crack untill the carbon in the groove is gone, then weld away. This should weld pretty good with out having to weld,grind,weld,grind.

    I use a mix of 75% ar/25% helium for all my aluminum work. It seems to burn off the oxides a lot better than straight argon

    Leave a comment:


  • HAWK
    replied
    VBI,

    The higher the arc frequency the narrower the arc cone all other factors being equal. I use a helium/argon blend to increase the heat to boil off oxide inclusions in some applications like cast aluminum. While the heat of the arc is increased the arc cone is widened due to the helium. The adjustable arc frequency can be increased to narrow the arc cone.

    Different joint configurations weld better with different arc frequencies. A fairly wide arc at 110 HZ makes a great fillet while I like a narrower arc (175HZ) works better for corner joints. The more you experiment the more uses you will find. I do not view ajdustable arc frequency as a have to for most applications. However, it sure can make things go together easier.

    Leave a comment:


  • VBI
    replied
    Hawk,
    I also have found the carbide burr made for aluminum and used with a die grinder to offer the most effective method of aluminum joint prep and also second the “SAIT” brand grinding disc for aluminum. It is amazing they do not clog solid with the spent material.

    Also, do you or others have some examples where you have experienced the AC output Hertz control that is available (with the inverter machines) to be well worth the investment over a regular transformer Syncrowave?

    Thanks.

    Leave a comment:

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