Page 3 of 3 FirstFirst 123
Results 31 to 35 of 35
  1. #31
    Join Date
    Jun 2010
    Location
    Canberra
    Posts
    1,322

    Default

    The biggest problem, as has been shown, is the arc wandering. Being electrical, it'll want to take the path of least resistance, so it'll tend to go to the closest metal surface. As far as I know, the only way to get around this is to run more amps and run a stronger arc that pushes into the root rather than jumping from side to side. However, with more amps comes more heat and more chance of blowing through.

    My preferred solution starts with "M" and ends with "IG".

  2. #32
    Join Date
    Aug 2010
    Location
    Near Bendigo, Victoria, AUS
    Age
    72
    Posts
    3,102

    Default

    Several people have mentioned 'waiting to let it cool'. You may have interpreted that to mean 'cool to room temperature' or something like that.
    What is meant by 'not rushing' is 'let it cool to black again' (not glowing), in other words 30 or 45 seconds or even less between short stitch welds. Certainly not half an hour.
    I noticed in your photo that you appear to have welded the full length of your bead in one go. That would almost certainly blow a hole if you had focussed the arc on the tube! On a 25mm RHS tube I would tack the corners, then run a 6mm bead along one edge another 6mm bead along the opposite edge and so on until the full weld was done. That way you don't have to hold or clamp anything after the first two tacks, you get little distortion and you don't have to wait. By the time you go from the last back to the first weld it is black again.
    You will find 2mm rods are easier to use - not because they are smaller, but because you can drop the Amperage. That's handy for a beginner. Later it is less important, because you will adjust your procedure to suit the heat produced 'instinctively'. 1.6mm rods are now difficult to get and are a nuiscance as others have mentioned.
    One other thing you might like to try: 2mm stainless rods, while expensive, require a lot less current, and may help you to slow down enough to see what is happening with the melted pool better. That way you learn to see what you need to see. Then you can go back to 6013 and speed up again.
    Many people use stainless rod for that reason on small or one-off jobs, when there isn't enough welding to be done to 'get your eye and hand in' - including me.
    Lastly, if you had 'your eye in', you would have seen the slag running under the molten metal in you photo - which is why the arc jumped to the tube. Since you didn;t see it happening, it is clear you have not yet had enough practice to see the floating molten slag on top of the molten steel reliably yet. There is a very small difference in colour between the two and the slag is just a little less 'runny' that the steel. But it can run under the steel in which case the arc 'gets out of the way', because molten steel is more conductive.
    You ABSOLUTELY need to actually SEE where the slag is floating to move your rod hand to 'maneuvre' or direct it. So I would actually recomment you practice on some thicker stuff a bit more until you can see where all the slag goes before it cools (a couple of millimeters behind the pool) and then try again with the thinner materials.
    I'm a reasonale welder with 2 years training at TAFE 45 years ago and been welding ever since. But even then, using a diffent machine or a different rod or changing from AC ot DC, for example, I often still grab a piece of scrap and put down a full rod or two before tackling the actual job. Sometimes it might just take a couple of tacks to realise it's OK to get on with it.
    My first experience with gasless MIG took more than a kg of wire for me to even feel confident that I could rely on the welds on thin wall tube!
    Cheers, Joe
    retired - less energy, more time to contemplate projects and more shed time....

  3. #33
    Join Date
    Dec 2014
    Location
    Adelaide
    Posts
    6

    Default

    Wondering if you using a right angle magnet
    to hold the RHS, as this will cause your ark to
    wander.


    images.jpg

  4. #34
    Join Date
    Jan 2004
    Location
    Mackay North Qld
    Posts
    6,446

    Default

    Quote Originally Posted by Njmpm View Post
    Can someone tell me why the weld seems to jump from the base to the square tube when I ran a bead. I started the bead on the base and ran it all the way along tight against the tube but keeping the rod focused on the base plate. When I removed the flux the weld started on the BASE jumped to the square tube then back to the base when I passed the end of the tube!
    Attachment 347293

    Oh and someone asked what welder I was using.. It's this one Weldsmart 140amp..

    Attachment 347294

    Well im having slightly more success now that I am trying to weld the full 2mm thick walls of the square tube. If I do a little bit at a time it doesn't seem to burn through as much.

    Cheers
    Nick
    Sorry no video.

    I was a Tafe metal welding teacher and can tell you I am no fan of introductory welding courses. It takes around twenty hours of arc time to make most people competent with one process alone.

    I believe have been deluded by those that ran this course. The course contents can't be adequately covered in those hours and then have a successful outcome of being able to operate your welder.

    Please understand I mean no disrespect or make criticism of your abilities.

    To get you where you want to be, a bit more practice is required and that will bring increased ability and self confidence. First up is look at problems in technique and how to overcome them.

    Ques 1. Can someone tell me why the weld seems to jump from the base to the square tube when I ran a bead. I started the bead on the base and ran it all the way along tight against the tube but keeping the rod focused on the base plate?

    If I understand correctly you are really asking is " why does the welding ARC jump from the base to the square tube when you ran the bead.

    What you describe is an arc affected by arc blow .Typically it occurs in DC machines on ferrous materials magnetically affected. If you are seeing this phenomenon through the shield as the arc is burning this is Arc Blow.DC machines tend to amplify this problem. Using a welding magnet to hold the pieces for tacking would give a similar effect.

    Cure : I. Move your earth (work ) clamp away as far a possible from the arc .
    2 Swap polarity - if welding electrode negative - change to electrode positive

    If using 6013 swap them for 6012 as the flux is not as thick and should offer better chances of success especially in conjunction with a short arc length and increased amps (not much mind you - between 5 - 10 amps).

    Satin craft are a prime example here, as many new fellas to welding are told the satin craft rods are the be all and end all of welding rods for new fellas to welding..Don't get me wrong , they are ok rod in their application but when used with lower amps and longer arc and driven too fast, long slag holes like in photo can be the result.You will rarely re weld over the top of them without further slag holes.

    Always completely remove the slag before attempting an over the top weld weld.

    At the same time make sure your travel drag angle is no more than 10 degrees off square. This ensures best penetration of the arc.
    I also noticed one the photos that showed a big crater at the end of the right to left bead.That something to address later on?

    Just to reinforce it all it again.
    1. Arc blow - shift earth and change polarity
    2. Change to 6012 9 (2.5,s are fine)
    3. Try increased amps ,shorter arc length and slower travel speed
    4. Travel angle - only 10 degrees or so, off vertical

    The above recommendations are all aimed at the 3mm square to flat bar joint using not the 1.6mm thickness.

    Its my belief,if you try the above techniques and adjustment of variables for a few hours you will be back on track before you know it.

    good luck

    Grahame

  5. #35
    Join Date
    Jan 2004
    Location
    Mackay North Qld
    Posts
    6,446

    Default

    It also occurred to me that to get really accurate manipulation of the electrode - and therefore the arc - another technique not thought about too often is supporting the electrode close to the arc.

    To explain further the electrode has support during the weld process in two places, at the electrode holder and across the top of the gloved finger of the opposite hand.

    The dominant hand holds the electrode holder while the electrode slides across the top the pointer finger of the other hand.

    It may work for some but can be problematic because of the proximity to the heat of the arc. My ( left-- non dominant) pointer finger is usually about 75mm or so back from the electrode end and slides with the travel.

    Obviously the bench has to be free of dags and dilberries to avoid catching the glove. Some , cut a piece of old glove wrapped around the fingers of the hand that the electrode slides on to help stop the heat.

    It takes a while to get used to and after that you don't notice it.

    For a lot of people its not too uncomfortable as generally beads are fairly short.

    Grahame

Page 3 of 3 FirstFirst 123

Similar Threads

  1. QUEENSLAND Cig welder transarc tradesman HD (stick/arc welder) 3phase
    By dkaoffroad in forum METALWORK - Machinery, Equipment, MARKET
    Replies: 0
    Last Post: 8th Jun 2013, 10:45 AM
  2. Square aluminum tube hinges?
    By eija in forum METALWORK GENERAL
    Replies: 4
    Last Post: 23rd Mar 2013, 09:15 PM
  3. thin weld bead
    By eskimo in forum WELDING
    Replies: 19
    Last Post: 25th Nov 2012, 11:13 PM
  4. Nesting steel square tube
    By Lyle in forum METALWORK GENERAL
    Replies: 14
    Last Post: 27th May 2011, 04:14 PM
  5. Welding thin rectangular tube
    By Tiger in forum WELDING
    Replies: 18
    Last Post: 20th Jul 2009, 10:55 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •