Welding 1/4 aluminium advice

  1. yorkie_chris Member

    Messages:
    68
    West Yorks
    Should be clean, it's new material.
    Some of the other bits that I need to attach to are outside though and have been there 20 year.

    p.s speaking of material would you recommend any suppliers of 5083? This lot came from aalco, some others didn't seem keen delivering to lancaster
     
  2. Hood

    Hood If it walks like a duck....

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    11,862
    Location:
    Carnoustie, Scotland
    I am in Scotland so the best suppliers for you may be different. I get mine from Richard Austin Alloys in Glasgow.
     
  3. Rrunnach

    Rrunnach www.interventiontechnolog y.com

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    Location:
    edinburgh
    I haven't read all the posts, so this may already have been covered and, not sure what type of boat you own, nor what covered structure will be used for. I can say, when I have viewed various added covered structures to working fishing boats, 3mm al/al has been the norm. I'd say 6mm maybe a tad over engineered? Also with 6mm a preheat would be advisable to reduce cold cracking at start of welds, or run on plates.

    3mm onto section will make positional welding, easier, less volts and amps required. As above, depends on the application of planned job?
     
  4. yorkie_chris Member

    Messages:
    68
    West Yorks
    Hey up
    It's a Danish ex-seine netter, 19m, 1966. I'm rebuilding her into a live aboard dive boat.

    This first job I am doing is new stanchions, the old timber ones are leaking around and a little squishy, so cutting them all off, fitting a new covering board around the deck. And making new stanchions from 8mm ally to put the bulwarks back on.

    The next job after that is to start building a saloon and galley structure on deck which will be 3mm plate over a framework - thinking to use 50x6 flat bar for the framework. The back of this structure needs welding to the wheelhouse, and the front of it needs incorporating in to the whaleback (shelter deck).

    Then I need to rip out 50 years worth of re wires, and do a proper job of putting some back, fit out all the interior, stick a diver lift on, get it Coded, get a skippers ticket and go diving. Simple!
     
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  5. Richard.

    Richard. Forum Supporter

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    You jinxed it mate last year
    Should of said nothing :laughing:
     
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  6. Hood

    Hood If it walks like a duck....

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    11,862
    Location:
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    Aye I know, will be hanging on to the 330 when I eventually get a 355..... Oh wait scrub that, I said nothing :D
     
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  7. Rrunnach

    Rrunnach www.interventiontechnolog y.com

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    WOW, this is a project, vocation is more appropriate. Liva board as in for you, or for x amount divers? I have been on some crackers when out on and under the Red Sea.

    Where will vessel be based? Also make sure you use marine grade alloy for your application (which I am sure you will know)

    This is ours moored on pontoon at Tobermory, Isle of Mull.
     
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  8. henry Kadzielski Member

    Messages:
    871
    Location:
    Australia Wollongong

    Just a small comment from me. In that pic at the bottom of your post, you have a pic of a alli stanchion attached to the cover board. Regardless of what grade of alli you use over time even 5083 with moisture underneath it, it will form that white gooi snot between itself and the deck. This will not happen straight away, but over time. Time is relative the more moisture between the alli and the deck the quicker it will form. One day you will notice a small amount corrosion the next time you notice it will be significant. It takes longer to form, but once started it progresses quite quickly. Only solution is to epoxy coat, minimum the entire base, and that had it's problems as well:(
     
  9. yorkie_chris Member

    Messages:
    68
    West Yorks
    Yes bit of a vocation!
    For some divers, 8-12 depending if they are technically inclined or not.

    She's in Lancaster at the moment. Probably staying there but venturing out to the irish sea, isle of man, northwest approaches, hebs etc.

    Yes marine grade, 5083. Although I did make a load of bits for another boat out of 6082 years ago and they've been fine, not sure it matters that much to be honest.
     
  10. yorkie_chris Member

    Messages:
    68
    West Yorks
    Yes I have seen this problem, I was just going to bed it down on a load of sikaflex type snot. I've got some epoxy paint spare but I'm not sure if it sticks to ally.
     
  11. yorkie_chris Member

    Messages:
    68
    West Yorks
    Welding question again....

    Doing a fillet weld which is overhead... I'm having a nightmare. Managed to keep the wind off so it hasn't gone porous but I can't get a bead. It seems to penetrate but just dribbles loads of metal all over. Too much wire?
     
  12. Brad93

    Brad93 M J B Engineering

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    9,327
    Location:
    Essex
    There’s absolutely minimal corrosion difference. What’s important is 5083 is stronger in the as welded condition.

    You may find 5083 doesn’t have as much susceptibility to stress corrosion cracking
     
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  13. Hood

    Hood If it walks like a duck....

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    11,862
    Location:
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    Should be ok if bedded on that, I use that quite a lot and it creates a good barrier and keeps out the moisture.

    With a standard Mig it can be a pain doing positional welding on Alu. I must admit overhead never gave me much of an issue but vertical could be a pain at times. Just have to make sure you are in spray transfer for Alu and weave a bit to play the puddle and that allow it to cool slightly as you go.
    With the pulse Mig it is a breeze :)
     
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  14. Hood

    Hood If it walks like a duck....

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    11,862
    Location:
    Carnoustie, Scotland
    Yes, use 6082 all the time as it is all I can get in extrusions and it does well.
     
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  15. Brad93

    Brad93 M J B Engineering

    Messages:
    9,327
    Location:
    Essex
    If you get setup right you should be able to just step and pause vertical up with standard mig.
     
  16. Brad93

    Brad93 M J B Engineering

    Messages:
    9,327
    Location:
    Essex
    Very rare you’ll find 5xxx series extrusions anyway.
    It wouldn’t bother me unless I was looking for maximum strength and there was a decent amount of welding.
     
  17. Hood

    Hood If it walks like a duck....

    Messages:
    11,862
    Location:
    Carnoustie, Scotland
    Yes it usually is that easy once you get the hang of it, where it becomes a bit harder is when welding say 3mm to 10mm or so, then you are trying to keep the heat on the thicker stuff so you start to get a bit of a build up and sag on it if you are not careful but practice wins in the end although I am probably out of practice now having being spoiled this last year with the pulse :D
     
  18. Rrunnach

    Rrunnach www.interventiontechnolog y.com

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    1,005
    Location:
    edinburgh
    When I was fab/welding ROV's for SS7 (avatar) it sticks in my head frame weldment was manu'd from 7000 series al/al @ 6mm thick. Possibly 7068, as I manu'ing work class ROV and, high tensile strength required.

    Initially, completed rovers were left bare, then aluchrom, then aluchrom and, then cathodic protection added to each rover. Mind you, depending on contract, some rovers could sit under salt water in their garage for a few weeks. I should mention, 100% TIG welded.

    Good to read folks attempts at sealing different materials within a structure within a salt water environment, sometimes or, most times, a wing and a prayer getting it right.

    Good project, look forward to progression posts...............cheers.
     
  19. henry Kadzielski Member

    Messages:
    871
    Location:
    Australia Wollongong
    I have to agree with hood regarding overhead, no problems at all. When I did my weld test positional for alli the test was two 6mm overhead butt weld plates, I thought you ripper I can do those:thumbup::thumbup:. The samples were then flipped over back gouged and then another pass put in, this then sent for DNV testing. Vertical up I found much more difficult, this however done on almost twenty year old Essetti pulse migs. I have done similar with 'Francis' TPS320i and much better and easier. I am putting that down to I know a little more now
     
  20. yorkie_chris Member

    Messages:
    68
    West Yorks
    Guess the problem is the spanner holding the torch then :-D
     
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