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  1. #31
    BobL is offline Member: Blue and white apron brigade
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    The first thing I would say is I'm not pro but the following might help.

    Clean up the area around the weld with an angle grinder and flap wheel until there is not a skerrick of rust/paint and all you can see id bright steel.

    My guess is you are not holding the stick close enough to the work to form a reasonable size puddle of steel in the work pieces. Remember that welding is not just an adhesive type process - the molten stick should not be the "glue" that holds the two pieces together but the weld process should blend metal from the pieces being joined with the weld rod. My guess is your stick angle may not also be right?

    Instead of practising a right angle joint I would start with running beads on a flat piece of steel.
    While welding you should be able to generate a few mm diameter molten metal puddle in the substrate in-between the stick and the weld and keep the puddle molten at all times.
    You should be able to run a straight, even width/height, with even depth penetration, bead at least 100mm long.
    The bead should clearly show no breaks and "even melting" of the substrate - not just scat like droppings on the top of the steel.
    When you can do this repeated 10 times in a row then progress to a simple lap and butt joints. If you can't break these joints with a hammer then you know you are starting to get somewhere.
    Then try a 90 join.

    Hopefully GrahameC can fill in the gaps.

  2. #32
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    BobL, here's a pic of the 2 wall mounted speed adjustable circulating fans in my workshop - they're purposely arranged to direct the 'air' towards the nearby entry door. The shed's lined & insulated skillion roof also has a 300mm Whirlybird Roof Ventilator. As for welding, the portable bench's readily attached mono wheel enables me to easily wheel it outside, thereafter, fumes will hopefully be safely exhausted away on the breeze !
    Attached Images Attached Images

  3. #33
    BobL is offline Member: Blue and white apron brigade
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    Quote Originally Posted by Chimbu View Post
    BobL, here's a pic of the 2 wall mounted speed adjustable circulating fans in my workshop - they're purposely arranged to direct the 'air' towards the nearby entry door. The shed's lined & insulated skillion roof also has a 300mm Whirlybird Roof Ventilator. As for welding, the portable bench's readily attached mono wheel enables me to easily wheel it outside, thereafter, fumes will hopefully be safely exhausted away on the breeze !
    Given how cramped you space looks, outside sounds like the way to go.

    FWIW, I'm afraid those pedestal type fans won't move a lot of air out of even a small shed. Trying to "push" dust or fumes using a fan is like herding cats, 90% of the fumes and dust ends up just being recirculated - operators can't see this because the fumes get diluted with other shed air. Even placing those fans at the door won't make a lot of difference. Fans are far more efficient at re-moving air/fumes/dust if they are sealed at their edges like a bathroom fan so the air is less likely to be recirculated. I have been measuring air flow by fans for some 40 years and still have flow measuring gear to measure the "real" fan flow rates. My testing of whirly bird fan flow rates was very disappointing as they really only move about half their claimed capacity and that is when the wind speed is around 10 kph so if the wind speed is less than this then they don't move much air at all.

  4. #34
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    Hi Chimbu,
    To me, the deposit appears to be down on amperage relative to the core wire diameter selected.

    I would say if it is a 2.5mm is needs 90 amps or if a 3.25mm 125 amps.They are just nominal figures for a reference not written in stone..

    The arc length ( the average distance between the workpiece and the unburnt end portion of the electrode being held in the electrode holder) needs to be shortened up. Its easy to say and hard to do until the "muscle memory" bourne of practice kicks in.
    The length, as a rule of thumb, is said to be that diameter of the electrode core wire you are welding with at the time.

    Something else that will make the electrode deposit more readily, is to clean the area that would be covered with the deposited bead. An angle grinder is often the preferable weapon of choice, but in a pinch, a file and hand wire brush will remove the majority of rust.

    When rust corrosion is not removed it melts into the weld metal and can lead to visible porosities and inclusions ( defects) in the bead. As Bob L notes, you are better served runnig flat beads first.
    To illustrate the arc length concept here is a diagram, also some comparison on deposited beads.
    The arc length is the major factor ,once you sort out the arc length you will certainly notice the difference.

    Grahame

    Arc length comparison.jpgGood & Bad stick welds.jpg

  5. #35
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    Grahame, I'd only prepared the surfaces with a steel brush so I'll lightly use a grinder before my next attempt. Yes, I was in fact using a 2.5mm Cigweld Satincraft 13 rod, with the dial incorrectly set to a lowly 75 Amps. I'll accordingly adjust it to 90 Amps and try positioning the electrode's tip at a 45 degree angle and 2.5mm from the actual workpiece - thus producing a 2.5mm arc length. I'm saving the related images for easy future reference....wow, have I got lots of 'practice homework' !
    Ross

  6. #36
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    BobL, I've definitely got to be more conscious in maintaining both a constant stick angle (eg 45 degrees) in addition to the distance between the electrode's tip and the workpiece (eg. 2.5mm). As you wisely mentioned, running multiple practice beads on a flat piece of steel's a sound idea. Such helpful advice, from the likes of you and Grahame, certainly is appreciated - much like when I took up the finicky but rewarding art of reloading back in '05, thanks largely to a number of similarly experience folk on a firearm/hunting oriented forum, namely, Shooters Forum - A shooting sports community

  7. #37
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    BobL, the fans truly are a blessing during hot weather as they noticeably 'push' much of the hot air outside via the shed's far corner door. The band saw creates a bit of circulating dust, otherwise, an improvised trolley mounted vacuum cleaner/dust collector's attached to the Miter Saw.

    Regarding your suggestion of placing a thin sheet of MS on my portable table when welding outside my workshop - I've got a 2mm thick aluminium tray (L71 x W51 x H5cm) that might be suitable, if not, I'll stroll down to my local Bunnings and see what's available.

  8. #38
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    When you new to something it is always a bit of a learning curve.

    I made a table for electrode/ amps selection which should cut out any guesswork.Again the settings are nominal and vary slightly from welder to welder and elctrode to to electrode.
    A comment I would make about Satincraft is they are not the pick of electrodes for learning practice. These electrodes do not tolerate a long arc length very well.

    I am not saying you should not use them but if you have an alternate 6013 electrode, try that instead. Otherwise you need to concentrate on keeping the satincraft electrode at a shorter arc.

    Grahame


    Amps set table copy.jpg

  9. #39
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    I'm no welder, as I said before, but where did you get the 45 deg electrode angle from?
    As the flux vapourises, it gives off a shielding gos mix around the arc and weld puddle, which in turn stops the molten metal oxydising and keeps a bit of plasma (from the air and the shielding gases) floating in the arc zone so the arc doesn't stop and start with each voltage wave of the 50Hz power supply.
    Try and visualise that bubble of gas and smoke which NEEDS to stay on the spot that's melted and between it and the end of the electrode. Now watch where that bubble goes when you change the electrode angle. If it immediately gets blown away by the arc, your angle is too shallow. If it accumulates so you can't see the molten puddle, the electrode angle is too steep.
    I was taught that the best angle is about 80 deg (just 10 deg off vertical!), but too difficult to maintain and see. So a compromise of maybe 70 to 60 deg or so is the best most of us can manage.
    image160.jpg

    Lastly, try to SEE the molten flux residue ("slag") floating on top of the molten puddle and solidifying just as it gets out of view. Where this liquid slag flows is controlled and directed by the electrode angle in ALL directions. The idea being that it MUST NOT flow UNDER the molten metal or in the spot where you are about to deposit molten electrode metal. So you have to sort of constantly balance this floating liquid on to p of the molten metal pool. Sounds like hearding cats and feels like it too for a long time, but eventually you can see and feel the difference of surface tension of metal and slag and maneuver the fluid slag where you want it.
    Cheers, Joe
    again completely retired - more time to contemplate projects and spend more shed time....

  10. #40
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    Hi Joe,
    I have been idly kicking my heels as we have had a power outage for a couple of hours. I was in the middle of an edit when lights out came.

    Perhaps the 45 degrees Chimbu mentions came from an estimation of my from my posted diagram of the short arc comparison post #34. It is one I quickly pinched of google. Graphic artists draw these things not welders and don't understand about welding drag angles..

    The intention was to emphasise the need for keeping a short arc. It is the predominant parameter in getting a learner up and running with a presentable weld bead.

    I do understand clearly what you are getting at concerning the molten metal overflowing the slag. A long arc length of say 95 amps has less penetrative power than a much shorter arc at the same amperage setting. On a long arc the arc voltage increases and the actual available arc amperage reduces. From memory it is mentioned somewhere in the Lincoln Procedure Handbook of Welding.
    The greater the inclination of the drag angle also means that the actual vertical depth of penetration is reduced.

    This all means that a longer arc has a much weaker arc force and does not bite in to the parent metal and as such does not force the slag out of the way. Certainly a declining angle allows this to happen as well.

    It is a sometimes difficult thing to learn coordination and minute precise speed hand control of the electrode in the two directions that are necessary to obtain the desired outcome.

    It is the major reason I prefer teach stick welding first, then mig welding as it is much harder to learn stick after you have mastered mig.

    Grahame

  11. #41
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    Joe, now that's what I call an in depth reply.....truly fantastic. I'm creating a reference file with such detailed helpful information. Talk about being on a huge learning curve and the need for lots of attentive practice sessions. As for the electrode's questionable 45 degree angle, well, I confess that in the course of briefly looking at YouTube clips some time ago relating to stick welding techniques an 'expert' suggested such an angle.....in short, I definitely need to be more discerning when seeking such tips. In comparison, thanks heaps for your informative input.

  12. #42
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    Grahame, I really like your concise but explicit explanations about the relative effects of different electrode angles and arc lengths.....pity you're not teaching welding at my local TAFE !! Excellent.

  13. #43
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    Quote Originally Posted by jhovel View Post
    Hi Ross,
    all good advice you are getting.
    One thing to watch out with the type of welder you inked to is the "VRD". This is a safety device to prevent people getting electrocuted in specific industrial environments - mainly moisture (like in mines etc).
    The side effect is that you CANNOT weld with low hydrogen electrodes. That is a concern for 'tinkerer welders', because you might want to use those for structural welds.
    I think you may have your wires crossed a little. Inverters with VRD's will run low hydrogen electrodes day in and out with no issues other than slightly harder arc initiation. In several of the applications you mentioned, mine sites, industrial plants and such, low hydrogen is pretty well all that is run. Open circuit voltage is less important with DC current as the current is constant rather than extinguishing and reigniting at 50Hz.

  14. #44
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    Maybe I have, Karl. My frustrating experience was that several DC inverter welders I tried to use 7016 and 7018 rods on simply would not maintain an arc at all. I measured the OCV and found the frustrating ones to be below 42V. I then tried my old transformer AC Welder with 55V OCV and it was 'less frustrating', but still not good welds. Re-starting almost impossible without chipping off the flux coating on the rod end. That old tranny has a 'Special electrode' connector with 70V OCV and off she went like a ripper. No trouble maintaining arc, good control, easy re-starting.
    I then looked at the specs and the rod packets are actually labelled for 50V min OCV. I looked at other brands and found them more or less all the same.
    I then looked for an inverter with higher OCV and measured it. My current Inverter has 55V OCV and works like a charm.
    I can only report my practical experience and frustrations and successes.
    So I have no idea how the mining people do it. I wonder if the pro inverters switch the VRD off for brief intervals when starting or re-starting and have it on when in use or when not making contact with a rod? In my mind that would work.
    Can you help explain my experience? Can others chirp in and report their experience with LH rods on lower end DC inverters?
    Cheers, Joe
    again completely retired - more time to contemplate projects and spend more shed time....

  15. #45
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    Jim,
    My Fronius inverter welder has run Low Hydrogen electrodes, starting without any problems.
    Possibly it may have something to do with my starting them on a striking plate.

    This clears the starter oxide on the end the electrode and the pre-strike brings up the electrode tip to a temperature that I can easily restrike on a weld bead. Mind that the electrode doesn't cool for any length of time after the initial strike.

    I will check this on the Token Tools inverter and report back.

    Grahame

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