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Building with aluminum

Discussion in 'Builds and Fabricators Forum' started by DanStew, Dec 17, 2013.

  1. Dec 17, 2013
    DanStew

    DanStew Preowned Merkin salesman Staff Member

    Lexington, South...
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    Sep 22, 2002
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    Since i have everything to work with aluminum i need a project. So like always i just sold off my offroad trailer, I am thinknig about making another but this time make it out of aluminum. My question is, Say i used 2x2 square tubing for a frame then 1x1 square to construct the box. If i used aluminum do i just use the same but use a thicker gauge? Or is aluminum a bit stronger than i am giving it?
     
    DanStew, Dec 17, 2013
    #1
  2. Dec 17, 2013
    Mike S

    Mike S Sponsor

    Cameron Park Ca.
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    Mike S, Dec 17, 2013
    #2
  3. Dec 17, 2013
    tarry99

    tarry99 Member

    Northern California
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    Structural extruded aluminum shapes like channel , angles , I beams & T's are normally made out of a 6061 series aluminum that has 45k psi strength.
    Aluminum tubing is only made in a 6063 series aluminum with 27k psi strength.
    Big difference in strength.................what method were you going to use to put this aluminum trailer together? Welding , Rivet's, bolts?............both of those 60 series aluminum are weldable via various methods.

    Not an easy answer depending on alloy as Mike mentioned ..........which will change your overall design.
     
    tarry99, Dec 17, 2013
    #3
  4. Dec 17, 2013
    DanStew

    DanStew Preowned Merkin salesman Staff Member

    Lexington, South...
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    It is simple structural. Just a small offroad type trailer. Welding frame, and sides. Will bolt on spring and shackle mounts and the coupler. It is the thicknesses I am questioning. I usually make my trailers with 1/8 or 3/16 thickness steel tubing. I will ask my metal distributer. I still need to price it all, if it is just way out of line on price, i will just do steel again. I just want to play with the spool gun for my welder and get practiced with aluminum.
     
    DanStew, Dec 17, 2013
    #4
  5. Dec 17, 2013
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
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    Steel frame and aluminum tub with adequate insulators to eliminate electrolytic reaction? Stainless fasteners between the two.


    Sent from my iPhone
     
    nickmil, Dec 17, 2013
    #5
  6. Dec 17, 2013
    Clatham

    Clatham New Member

    San Diego, CA
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    Steel has a Young's Modulus, measure of structural stiffness, of 29x10^6 psi and aluminum has a modulus of 10x10^6 psi. This means that for a given section the aluminum is only about 1/3 as stiff. ASTM A500 Grade A tubing has a yield of 33 ksi (33,000 psi), Grade B has 42 ksi. The other issue you need to consider is fatigue life. Steel under low stress levels has almost infinite fatigue life. Aluminum has a much lower fatigue life. There are steel bridges over 100 years old but aluminum aircraft have a much shorter life.
     
    Clatham, Dec 17, 2013
    #6
  7. Dec 19, 2013
    duffer

    duffer Rodent Power

    Bozeman, MT
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    This above all else. Where you attach tongue and spring mounts, I would use either heavy material like 1/2" or gusset the hell out of it. I once machined an alternator mount for a head mounted unit on a sbc out of a good sized chunk of 6061, leaving a 1/4" thick piece for the forward arm of the bracket. It broke (on the trail). I left a half inch on the latest version and thatt has held. If there is any notable flex, you will have problems.

    A spool gun does a decent job on aluminum down to maybe 1/16" but, at least for me, it gets a bit tricky thinner than that.
     
    duffer, Dec 19, 2013
    #7
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