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  1. #1
    Join Date
    Aug 2009
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    Sydney, NSW, Australia
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    Default Prep advice? Going to tig this hole

    Going to weld up this hole first option was mig but i dont have a teflon liner so going to fire up the tig and have a go, i have a piece if 100x50x3 brass backing shop didnt have copper

    Any advice on cleaning? I am know to be not so clean and get impurities in the weld

    Finger is for reference, was quoted $200 to repair, $300 for a new starter but i need the practice
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  2. #2
    Join Date
    Oct 2011
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    Norwood-ish, Adelaide
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    Default

    Brass is no good - the zinc will come out and play havoc with the weld. It needs to be copper.

    Michael

  3. #3
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    Default

    Thanks Michael any idea what i can use for backing? The steel shop is 30mins each way away

  4. #4
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    Nov 2017
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    Geelong, Australia
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    Default

    If you've got a bit of copper water pipe you could try flattening that.

    Steve

  5. #5
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    Oct 2011
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    Default

    Rather than try to fill the whole lot, my preferred method would be to neaten up the hole and make up a patch to match. The whole thing will need to machined anyway before it's able to be used, so build up can be tolerated.

    Michael

  6. #6
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    Default

    Thanks for that idea Steve bunnings is just around the corner

    Michael thats an idea it will save a lot of gas and i have some 4mm sheet in the shed will hitting the aluminium with a steel hammer effect how it welds?

  7. #7
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    Default

    Shouldn't do (unless you embed bits of steel in the Al when you hit it - unlikely unless the hammer shatters )

    Michael

  8. #8
    Join Date
    Sep 2010
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    Lebrina
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    Default

    Definitely better to make a section and then weld it in as you will get substantial shrinkage if you just fully weld it which will potentially distort far more than just the repaired area. Being a casting, it may well weld like crap, so be prepared for the odd rework. All things are possible with forethought, skill and patience. IE, think about the job, prep it well (cleanliness) and if it starts going pear shaped, then stop and reassess.
    Steel or stainless will act as a backing for Aluminium. I don't personally like copper all that much for Aluminium as it tends to suck the heat away. Pay attention to letting the piece cool evenly so as to avoid cracking.

  9. #9
    Join Date
    Aug 2009
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    Sydney, NSW, Australia
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    Default

    Thanks for the help to those who have offered advice i made the blank bit today to fill in the hole my fitment is not 100 percent perfect there are tiny gaps i hope i can bridge these gaps without blowing a hole right thru it my machine is pre set amps so not foot peddle to vary the amps
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  10. #10
    Join Date
    Nov 2017
    Location
    Geelong, Australia
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    Default

    Does your welder have a downslope setting?
    I don't have a pedal on mine either, but find I can get a bit of variable control by setting the downslope a bit longer then releasing the torch trigger and pressing it again as the current reduces (before the arc stops).
    Basically if the weld pool starts to get away I release the trigger, then back on again. The longer you wait before hitting the trigger again the more the current reduces.
    If you time it right its a bit like a manual pulse mode!

    Steve

  11. #11
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    Default

    Steve i think it does and thats a neat little trick i'll see how i go

  12. #12
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    Sep 2010
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    Lebrina
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    Default

    I think you need to pay more attention to the shape of your infill patch. It is too flat (not enough curve) and once machined you will potentially have a thin spot. It would also be a good idea to ensure all of the joint is bevelled out to allow penetration.
    What happened to the pieces that broke out originally? Often they are the best infill.
    Is your little lathe up to the task of holding and machining the casting back to shape once welded?
    Pay attention to the details as you will probably only get one go at this, two if you are really lucky.

  13. #13
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    Hey Karl, The bits that had broken off were tiny pieces it wasn't one big piece i will attach a pic, i was going to use a die grinder bit in a drill to shape it doesn't have to be perfect and it doesn't have to be super strong as one of the internal ring gears is plastic
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  14. #14
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    Aug 2009
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    Fighting with the tools tig regulator hose was one size regulator nipple was 1/4" solenoid nipple was 3/8" tried to make a hose fit but the hose kept folding in on its self than the solenoid wasnt working so pulled out the Unimig 200 Razor and just mig welded it

    really good penetration but a bit of impurities not sure if it was because i had no backing and it was sucking air thru the gaps or if it were in the metal or my cleaning

    after some sanding it came up pretty good
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  15. #15
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    Nov 2017
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    Geelong, Australia
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    Default

    Well done!!

    Steve

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