Welding a steel hopper. 2mm thick sheet

  1. Gorlist New Member

    Messages:
    9
    Location:
    Cornwall
    Good morning, just at the moment designing a grain hopper for the farm to go on my seed drill - there not terribly large (450mm h x 250mm w x 500mm d) accept I need to weld 8 of them. Laser cut and bent by a firm, and then my intention was to seam weld using my mig. The design is for 2mm sheet at the moment.

    Should this be welded from the outside or inside?

    Apart from repairing my Land Rover bulkhead I've not worked with a great deal of sheet steel, and unfortunately all my local steel firms have closed and I'm worried if I don't get this order done now its not going to arrive come May...and I have no steel kicking around to practice (or gas for that matter!)

    My intention was to obviously tack weld and then work in sections.

    I could get it done in 3mm sheet steel rather than 2mm but apart from the marginal cost increase it make the hopper considerably heavier.

    Dad wanted me to put tabs on, bent and then plug welded (given im on a budget so no spot welder) but I think it needs a closed seams given how small clover/chicory can be! I can imaging a small air gap.

    Attached two pictures, the second one is the flat sheet steel which shows the number of seams. Any advice would be appreciated!

    Thanks, James
     
    • Mig1.jpg
    • Mig2.jpg
    Shedendman likes this.
  2. waddycall

    waddycall Member

    Messages:
    1,009
    United Kingdom
    Do they need to be welded? Could you rivet them? Could you fill the gaps with anything other than weld e.g. sealant?
     
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  3. wyn

    wyn Member

    Messages:
    3,052
    Location:
    Cardiff
    If you could get some sort of beads rolled into the flat surfaces you could get away with thiner material.
     
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  4. Brad93

    Brad93 M J B Engineering

    Messages:
    6,825
    Location:
    Essex
    Tack from the outside and weld from the inside vertical down as quick as possible.
     
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  5. Shedendman

    Shedendman Member

    Messages:
    3,931
    east sussex
    Did you design that cutting template yourself or is there some program for doing so,just out of interest
     
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  6. owas

    owas Member

    Messages:
    1,706
    Location:
    Birmingham
    I used to do a similar job quite frequently and same as Brad says, vertical down quick on the inside.
    Get the settings just right and it's easy
     
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  7. Gorlist New Member

    Messages:
    9
    Location:
    Cornwall
    Thank you for the replies. I think I'll do as you both suggest Brad, Owas - will also up it to 3mm thickness as its better grade steel regardless.

    Not really that keen on riveting, I'm sure it would be fine especially after sealing it but its just more work with the tabs etc.

    CAD software, S.Works, but I reckon something must be in google sketch up. Or any 3d program, you could model and then UV unwrap it to give you a 2d template but obviously no specialized tools. I'm no engineer but use to do 3d design as farm diversification years ago :)
     
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  8. Brad93

    Brad93 M J B Engineering

    Messages:
    6,825
    Location:
    Essex
    If doing it from 3mm you could do outside corner then and pen through to the inside.
     
  9. pedrobedro

    pedrobedro Man at Matalan

    Messages:
    10,139
    Location:
    CX Derbyshire
    I reckon my Minarc mig would do that on his 2mm if the gaps were close enough.
     
  10. Hitch

    Hitch Moderator Staff Member

    Messages:
    12,020
    Somerset
    That looks like a pain to form up.
    I'd be inclined to do it in 4 bits, and just outside corner weld the lot. Bit more welding, but probably cheaper to have folded.
     
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  11. Paul.

    Paul. Moderator Staff Member

    Messages:
    6,274
    Location:
    Northampton. UK
    Exactly how I'd do it (and have done many times) hours job at most, its only a seed drill no need to over complicate it and no need to weld the inside, its not required to be food safe.
     
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  12. Gorlist New Member

    Messages:
    9
    Location:
    Cornwall
    The firm quoted 40 euro's for the steel, to laser cut and fold so if they think it can be done... I guess means less welding for me. Its not sufficiently cheaper if its in four sections to make that much of a difference. The problem is if I order just one it's 94 euro's so I need to do a batch for the better price, so its not as if I can prototype off hand with time running out because its a 4 week turn around :) I will post a picture of the end result when I get there.
     
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  13. Mikes Member

    Messages:
    111
    Location:
    Hutton, Essex
    Euros ? Has Cornwall broken away from the UK and joined Eire or France?
     
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  14. dannyp Member

    if i was making that at work, to make it quick id go for 3mm and outside corner it, downhill fast

    2mm is rather a lot more hasstel as have to weld from inside then try and make the outside look nice and smallest wire we have is 1mm so fitup has to be more or less bang on
     
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