Burnback control

  1. Radar Member

    Firstly congratulations on a great site, perfect for a newbie like me!

    Can anybody tell me what the burnback control should be set at for any given wire speed and exactly what it does?

    Thanks in advance.

    Radar.
     
  2. Hitch

    Hitch Moderator Staff Member

    Messages:
    12,308
    Somerset
    Hi Radar.
    A 'burnback' control sets the amount of wire to 'burn back' after you release the trigger of your torch. For example, with a max burnback, once you have finished a weld, the wire will burn almost right back to the tip.

    Just set it somewhere in the low to middle and you should be ok.
     
  3. Radar Member

    Thanks for that Hitachimad, now it makes sense. Maybe now I wont go through so many tips!
     
  4. Hitch

    Hitch Moderator Staff Member

    Messages:
    12,308
    Somerset
    Yes, that should sort it out mate!!
     
  5. malcolm

    malcolm & Clementine the Cat

    Messages:
    9,129
    Location:
    Bedford UK
    Do welders like mine with no burn back control have some sort of timer to burn the wire back after the trigger has been released?

    I don't recall the wire ever becoming stuck in the weld after welding, but invariably end up with a small blob of metal on the end of the wire.
     
  6. Hitch

    Hitch Moderator Staff Member

    Messages:
    12,308
    Somerset
    The Migatronic i use at work does, its a variable timer, inside the machine.
    But my home set doesnt. Not sure how it works on a budget machine, sorry Malc!
     
  7. t_ha23 New Member

    What was causing you too go through so many tips??
     
  8. Wozzaaah

    Wozzaaah The wizard of woz Staff Member

    Messages:
    15,036
    Wiltshire, UK
    Threads over 3 years old fella, Radar's well and truly gone I think seeing as he only ever posted twice and that was in this thread ;)
    Usual causes of tip failure is operator error or poorly maintained machine ;)
     
  9. mykemrc New Member

    Messages:
    1
    brantford, canada
    hey hitch it sounds like you know your stuff. ive been welding for about 10 years but have never learned how to "fine tune" a welding machine. i just learned about burnback today when there were people laughing at me at work today when i couldnt fix that problem. Im hoping you could tell me what the other controls that are there do to your weld/welder. 10 years and i got laughed at...my welder ego is at 0 and i know its time to do my own schoolin.
     
  10. Gozzo New Member

    Messages:
    1
    Location:
    Australia South West Queensland
    Hi have just read the above Q&A, and it leaves me with a serious Question “ A Friend “ of mine who is a professional welder with extreme amounts of experience and qualifications. When I asked him what the burnback control was for, he told me to forget it was even there.To pay it no heed. Can I take that to be he has fed me disinformation, that could possibly be holding me back. Against his advice I bought a “Bossweld MST 195 “ which the store had given me an incorrect quote of $300aud instead of $749aud. I realise that’s a cheap price for a 3 in 1 function machine. It’s the first machine I have ever used with Argon/CO2 75/25 or any other gas. I asked him what I should set the gas flow rate at for mild steel and despite this forum and others stating around 10liters a minute he told me a minimum of 20liters. I am a toatal Noob. So was relying on him to give me solid advice. He has also told me that given my machine is a lift Tig, so it’s next to useless apparently, is this guy just giving me B/S information. Therefore deliberately holding me back. Please do not holdback on either negative or positive feedback.I really need to know if this guys on my side or not.
     
  11. Richard.

    Richard. Forum Supporter

    Messages:
    18,350
    Location:
    Cambridgeshire
    Burn back control isn’t available on all machines but that doesn’t mean it’s not there. It’s just not adjustable. If it is there to adjust it’s a nice little feature to pre set the amount of wire sticking out from the tip when you come off the trigger. If it just stopped dead your wire would be stuck to the job. And too much you’ll be changing the tip every run.
    Lpm on a mag set up Varys a lot depending on current, joint, consumable and most importantly conditions around you.
    Assuming a solid wire 0.8-1.0mm in non drafty conditions up to say 220 amps I’d be looking at 10-15lpm. 10 as an absolute minimum really. Start getting into flux core or aluminium or working outside and we start going up into 18-22lpm.
    Tig. A lot of people are going to tell you Hf is the only way to go and that’s simply because it’s much easier to perform a contamination free weld. Lift and scratch both slightly different Processes but both require the tungsten to be in contact with the job to initiate the arc. Now advanced lift settings can allow for things like slope and post gas settings which make it much nicer on weld termination. Let’s say it’s most basic. Scratch start permanent live on full ocv tig. It’s not as useless as people think and in some cases essential*.
    You just learn the techniques of flicking in and snapping out and you have another Process, another string to your bow so if it’s there don’t dismiss it, learn to use it.
    * Hf tig generates a high frequency spark and this high frequency can cause interference with sensitive equipment around you. It can cause damage to this equipment. In these rare cases it’s actually more sensible to adopt a contact ignition Process to avoid the risk altogether. This is the reason the best tig sets in the world give you the option to turn the Hf off. It’s not there to help improve your skills it’s got purpose.
     
    Gozzo and slim_boy_fat like this.
  12. Richard.

    Richard. Forum Supporter

    Messages:
    18,350
    Location:
    Cambridgeshire
    I’m not denying shroud size makes a difference. I know it does. I could of wrote an essay on each individual case scenario if I had the time but as you’d already covered that in your post I thought I’d say some different points and elaborate the most important one that really makes more difference than the others. Wind conditions.
     
    Gozzo likes this.
  13. Richard.

    Richard. Forum Supporter

    Messages:
    18,350
    Location:
    Cambridgeshire
    It’s the same with tig. Through my no7 go to for everything cup I’ll be around 6lpm. Through a no 12 cup on exotics I could up that to 10lpm and in drafty conditions I could be up as high as 12-14lpm if I need it. For an inside corner joint I might only need 5 for an outside corner 7-8. 30amps I’d be happy with 5 Lpm. 150 amps I might need 6-8.
     
    Gozzo likes this.
  14. Liquid Metal

    Liquid Metal Member

    Messages:
    459
    Location:
    Essex, UK
    With tig welding, gas flow rates have so many varying factors as said above by Richard, nozzle size, joint configuration and position, material and all sorts, agree completely there. As i also agree with the difference between what works in an industrial setting sometimes isnt best for a homework job in the garage.

    As far as burnback control goes, i dont have it set too high on the set i use most of the time at work, because of how as the wire burns back, you end up with a blob on the end of the wire, unless you have a super dooper digital welder that stops it happening somehow (no idea myself). That blob unless you snip it off, can cause problems with popping and farting as you start the next weld.

    For the last too long the jobs i work on with mig, its mainly 3-5mm thickness steel, mostly 2-6" welds and stiches, hundreds of them, totalling up to god knows how many meters a day. I have it set so that it simply stops the wire sticking into the puddle as it freezes at the end of a weld leaving hardly any sort of blob on the wire for a nice clean start.
     
  15. normspanners Member

    Messages:
    8,852
    northwales
    My first portable snapon machine (a small cebora IIRC ) had built in timer on the burn back and was a pain it left far too much wire sticking out, and for thin work, weld stop /human pulse welding;), was virtually impossible so I checked the circuit and there was an RC resistor capacitor circuit on the board with four caps, so I reduced the number of caps one by one, till down to one and that was perfect for all my needs, I could have used a variable resistor or potentiometer to adjust the time and fitted it to the controls but didnt need it, it just worked at either end of the scale. as was. I was going to send it back to snap on coz before it was useless for bodywork.
    on one boc machine, I did find the supply voltage made a BIG difference to the wire speed/ burn back and even the burn back at min was still out of range, but that was straight off the sub at 250+V!!:o, and needed a transformer to calm it.
     
    Richard. likes this.
  16. wookie Member

    Messages:
    2,597
    Location:
    .
    Could not agree with you more... I learnt on scratch then years later moved over to HF, known a few guys that wouldn't entertain scratch but I always argued with then it was their technique that was lacking rather than the machine.

    It's a bit like ABS, any idiot should be able to stop safely with it but a decent driver will stop faster without it.
     
    pdg likes this.
  17. Morrisman

    Morrisman Forum Supporter

    Messages:
    2,387
    Location:
    Staffordshire, England
    I just bought a Rtech 180 and I’m pretty pleased with it, but I found it annoying there was always an inch of wire poking out after every weld.

    Then I discovered that if I left the torch in place briefly after I released the trigger it would actually burn back to exactly the length it needed to be. I assume that is built in burn back.

    After many years arc welding I was so used to pulling the stick out quickly after the weld was finished.
     
  18. Farside

    Farside Badly Welded Man

    Messages:
    3,687
    Location:
    Ireland
    Hah, that's exactly what I've found recently - and I was treating the torch the same way as the stick - get it out of the way sharpish. I must try that above.
     
    Morrisman likes this.
  19. w124 Member

    Messages:
    103
    Location:
    poland
    that is exactly what one of our tig welders is doing after i set downslope on 4T for 2 seconds on aluminum, leaving a crater and speaking s*** about the machine :laughing:
     
  20. Farside

    Farside Badly Welded Man

    Messages:
    3,687
    Location:
    Ireland
    I tried that today and it worked. Release the trigger, a quarter of a second later pull the torch away. Once I sussed the delay needed it became simple. I'm not sure if there's a capacitor bank in this machine or not, or what the inductance value is, but it works with what's there.
     
    Morrisman likes this.
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