Aluminum Brazing

Discussion in 'Motorized Bicycle Welding, Fabrication and Paintin' started by Mike B, Mar 4, 2015.

  1. Mike B

    Mike B New Member

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    This is so cool. I saw this stuff on the internet but didn't buy because it was really expensive. Then I saw some at the hardware store and thought why not? Don't need oxy-acetylene, just propane and a stainless steel brush. You just heat the part, scratch the rod until it melts and then brush the melt to "tin" the area.

    [​IMG]

    Then put the prepped parts together and scratch and flow more rod into the joint;

    [​IMG]

    You can see how some of the stock has dissolved into the melt. That was encouraging, what I was looking for. But is it strong, will it hold? One way to find out eh, give it the "hammer test"

    So I put the "cross" on the pavement and beat the crap out of it;

    [​IMG]

    Not even one little crack. This is so cool! Just think of all the cool aluminum stuff you can do w/o a welder!

    [​IMG]

    That was my first joint. Now I'm confident enough to build up the battery box for the Motoped
     
  2. Intrepid Wheelwoman

    Intrepid Wheelwoman New Member

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    Yes I've heard about that alloy brazing rod too Mike and I was planning on buying some. Many years ago now I was shown how to weld aluminum using an oxy-acetylene torch, but I never was able to get the knack of doing it and always ended up with more holes than weld. :(
    But with this new rod suddenly all the things I want to make in aluminium become possible :)
     
  3. cannonball2

    cannonball2 Active Member

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    Way cool! Don't you need the cobalt blue goggles for aluminum?
     
  4. Theon

    Theon New Member

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    I believe there is a trick involving using a little chalk, the chalk will discolour Just before the alloy 'drops'.
     
  5. Davezilla

    Davezilla New Member

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    I've used that stuff before and it takes a little getting used to... too cold and it wont flow well, too hot and it wont stick, and the aluminum needs to be constantly brushed clean, but once I did my first successful braze I was hooked... I welded a piece of angle to a 1/8" thick piece of sheet aluminum, then I put it in a vise and beat the **** out of it until I broke off a chunk of aluminum but the weld held strong.
    This stuff worked great for adding brackets and tabs to my old gsxr 750 frame and since then I've always kept a stash of these rods in with the rest of my welding goodies.
    I would recommend this stuff to anyone and advise to practice on scrap metal to get a feel for how it works before trying it on anything important, but once practiced up its like riding a bicycle... once ya learn ya never forget.
     
  6. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    Aluminazing......pretty amazing!
     
  7. wret

    wret Member

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    I've played around with the Harbor Freight low temp welding rods, which seem similar. They do work but the limitation is you can only make one weld on a small piece. When you try to weld another area the prior weld comes apart from the heat.
     
  8. Theon

    Theon New Member

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    When making silver jewelry, often the piece is wired together before silver soldering to hold all pieces in place.
    Maybe similar could be done?
     
  9. Trey

    Trey $50 Cruiser

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    Mike- I've been considering using AlumiWeld, which is similar, for a gas tank.
    Thanks for this note.
     
  10. Mike B

    Mike B New Member

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    That's the stuff I saw on the internet, the guy doing the repair on the hole in the Coke can!

    Their prices are much lower now, I guess competition is a good thing - :)
     
  11. curtisfox

    curtisfox Well-Known Member

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    What is nice is you can stick a metal bolt in a striped out hole and weld around it, when it cools you can back the bolt out and end up with new threads ...........Curt
     
  12. MEASURE TWICE

    MEASURE TWICE Active Member

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    I saw this stuff at AirGas and it was a bit expensive back a year ago. I chimed in on some threads here about this stuff before. What was my concern back then was that the propane torch I have would not have enough heat and area that could be heated at one time.

    I hear the ones that use a swirl tip may be better, but my propane torch is just a regular flow. It will be a while before I have a chance to see if it will work, but would like to know what torch was used for the work in the photos.
     
  13. Intrepid Wheelwoman

    Intrepid Wheelwoman New Member

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    I think you would need to use a swirl tip or turbo tip torch.
     
  14. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    Mapp gas swirl tip torch will work just fine......a cheap way to join aluminum or aluminium as the aussies and kiwis call it :D
     
  15. curtisfox

    curtisfox Well-Known Member

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    I watched a demo at the "Back to the Fiftys" and he was welding aluminum cans with just a regular propane torch. With the alum-a-weld but don't know about heavy things.......Curt
     
  16. Mike B

    Mike B New Member

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    I used a Bernzomatic high output swirl torch with Mapp. From what I've seen propane would work just as good. The rod melts at 730F, you don't have to get it really hot and you need to keep "scratching" the rod while heating to even see if it's hot enough as you can't see any change in the stock. As with all brazing you heat the parts and the part melts the rod. The "scratching" and brushing are to break through the oxide.

    I was impressed to say the least, I was not expecting my first joint to come out as nice and easy as I saw on the videos. I was really impressed after beating the crap out of the part showed no failure of the joint.
     
  17. mapbike

    mapbike Active Member

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    I have ised the aluma weld rods and they do a good job if used right, I have used propane and mapp gas with good results.

    One of the very important things is clean area to be welded, use a wood handled stainless wire brush, acetone or methylene chloride to clean surface real good and never put direct heat on rod.

    once the alumi weld is totally bonded to the aluminum it is some very tough and durable stuff.
     
  18. KCvale

    KCvale Active Member

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    Neat.
    I don't do much fabing here but there are times when bonding a couple of odd pieces of AL together would really be handy.
    Thanks for sharing.
     
  19. Davezilla

    Davezilla New Member

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    I always keep some of these rods on hand in my garage and at the shop, they do take practice and if you can monitor the temperature as well as keep the temp as close to 700F as possible and keep the parts clamped together the stuff works great. I've successfully used it with propane and mapp gas but still do a practice run with scrap metal right before doing anything important and watch the temperature by using an infrared point and shoot thermometer so I can get a real good idea how long to keep the heat on the part, then there's a narrow window of time when everything will flow real nice but that window can be much wider if working with larger thicker pieces. The other secret is to constantly clean the metal with a stainless wire brush as the aluminum contaminates really quickly when heated.
     
  20. highstrung74

    highstrung74 New Member

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    tell me the BEST place to purchase this product please....thanks in advance
    Dallas Dean
     

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