Mk5 Transit Minibus Project

  1. What's wrong with the welding? which pictures/bits.

    How can I improve the welding to at least MOT standard?

    Should I grind them off & start again?
     
  2. schnappi Member

    Messages:
    134
    Essex
    Looks to me like you've got an unstable arc. Lots of blobs, bits of wire stuck in the job. Either you're welding rusty steel, have a bad earth, have run out of gas or are welding outside in windy conditions.

    Looking at the amount of brown sooty stuff about, I'd guess no gas or wind blowing the gas away?

    As far as the MOT is concerned, if you tidy it up with a grinder / flap disc and the weld appears continuous the MOT man will be happy.

    For the panel work, if it tidies up ok then no worries. It's the prospect of doing any truly structural welding to that standard that's worrying.

    Look at the tutorials on here and then look at the welds on the van. They're worlds apart.

    The welding in the picture with the bolt heads in it looks mostly decent, what did you do differently to achieve those results?
     
  3. keith19 Forum Supporter

    Messages:
    1,346
    Midlands UK
    As Schnappi says, clean up the worst areas with a grinder or flap disc, then look for gaps in the welding seams that remain. Go over these carefully and tack up the gaps, and any holes if there are any. The idea for the MOT is to make a continuous seam without gaps. As you are pushed for time, do this on the structural areas where it will be seen by the tester first, like the underside, and make these good.

    Don't try to go over the top of the whole lot again in a continuous bead, as this could make it worse.

    Study the tacking technique in the tutorials, and apply it to your work.
    Turn up the power a bit for your tacks, and keep them short and sharp. Gradually join up your original welds.

    You'll get there okay, but your problem is that you don't have much time overall so have cracked on with the job at the expense of weld quality. We've all done this at one time or another, even at work, until we've learned better. Going over it a second time gradually teaches us that it's easier to get it right first time.

    I think we'd all give you ten out of ten for enthusiasm, you have got a lot of work done very quickly. If you can learn with the same enthusiasm you'll do well.
     
  4. gavuk

    gavuk artful-bodger

    Messages:
    2,951
    uk wiltshire
    What happened to the training Ron,definetly room for improvement :welder:.....as Schnappi,pic with the bolts is soo much better what happened?...looks like a lack of gas ,too little amps and lack of cleaning back to shiny metal,
    When under the van set up some wind blocks,I used some old ply but carpet ,cloth anything definetly helps ,did you try running the weld or was it Thin metal technique?..if it was the later make sure the area is clean and make sure your amps are high enough to melt the metal quickly and try and overlap,point the wire at the front edge of the last cooling weld and trigger again before it cools to black,mentally count get a rhythm,and don't do more than an inch at any one time to avoid distortion.
    Take your time ,its much quicker to weld right than to grind to make it look prettier :clapping:..
    best of luck Ron
     
  5. Thanks for all the comments, all of which have been taken onboard.

    Lawnmowerboy did not turn up, told me he broke his arm the day before, hope he gets better soon.

    The time frame has been cancelled, it will be ready when it is safe & ready.

    From the comments I would agree with them all, thanks for pointing me in the right direction.
     
  6. schnappi Member

    Messages:
    134
    Essex
    Stick with it and you'll get it done, it'll will all come together. For vehicles you'll find the thin metal technique gavuk describes the most useful. There's a video tutorial on this site to help too.

    I find I get on best with a slight variation sometimes described as the backstep method where you weld about 1/4" in the opposite direction to the overall direction you're travelling. Then stop welding and quickly move 1/4" ahead of the weld you've just done and weld back towards it. I like this method because just as you hit the point where you'd likely blow a hole you hit the previous weld which it melts into nicely and takes a bit of the heat away.

    It's a bit like this...

    Overall direction of travel
    ----------------------------------->

    Short welds
    1st 2nd 3rd 4th...
    <---<---<---<---<---<---<---<---<---

    Once you've got the settings right on the MIG (ie. you've got that sizzle sound) then, as others have stated, it's more about finding a rhythm that works and going at it almost robotically.

    Another thing I find helps loads is to use a reactive welding sheild so you can weld using both hands. I'm right handed and I hold the torch and operate the trigger with my right hand whilst holding the swan neck between my thumb and index finger of my left hand (palm facing towards me). I can then finely control the weld with the fingers of my left hand which is much easier than trying to do the same using only my right wrist. I often rest the back of my left hand against the object I'm welding which helps keep the torch a constant distance from the workpiece as I move.

    Another tip is to light the area you're welding with an old desk light with an eco bulb fitted. This helps you to see what you're welding much more easily and the eco bulb doesn't trip the reactive welding shield like a filament bulb does.

    I'm not saying any of this is best practice, it's just what works well for me when I'm welding up vehicles.

    Keep the pictures coming, I'm really interested seeing this van resurrected.
     
  7. Chickenjohn

    Chickenjohn Morris Minor and Porsche 944 fan

    Messages:
    1,284
    Location:
    East Kent
    I have to agree with the comments! these welds look acceptable.

    [​IMG]

    But these [​IMG] and all the others look awful.

    As well as the excellent comments from the others, I'd like to add, make sure you have decent lighting underneath the van, use a reactive mask, so you can aim better and get the distance and technique of welding right and make sure you clean the metal up properly.
    Use a wire brush on a grinder for this. Trying to weld to rusty metal is never going to get good results!

    It looks like you can weld from the first pic but need to be consistent.

    To be honest, apart from the first pic, I would cut it all off and start again. Or at the very least, grind down to make sure you have penetration. Oh and get a knowledgable friend to try your welder and make sure it is working properly.

    but most of all, don't give up! You can do decent welds as shown on the one pic. Good on you for taking the comments well.
     
  8. Thanks everyone, keep the comments coming good or bad, be as honest & brutal as you like, it's the only way I will learn correctly & know not to do something that could be dangerous. :clapping:

    One thing I did earlier to test the welder was grind a 3mm plate all over to shiny & attach the earth clamp to it, shielded from the wind & tried running a few beads like the 1st picture.
    The problem I had was every time I could never get a constant arc, it was always like a slow machine gun pop pop pop.
    Tried moving the earth clamp about, changing the settings & wire speed and it is always like a slow machine gun pop pop pop, can not get a constant arc?

    Surly I must get a constant arc to weld beads correctly, am I right in thinking that? :laughing: could the welder be faulty? What could have happened as it must of worked right once as in the 1st picture.

    Could it be the wire? Bought 5kg 0.6mm from a high street car centre as weldequip did not have any.

    Any suggestions?
     
  9. david500 Member

    Messages:
    105
    UK
    Its probably a wire feed problem causing the pop pop, Check the wire is coming off the reel smoothly and not wrapping around itself and stopping, cheap wire does that.
    Could also be rusty wire, Clean the feed rollers and check there is enough tension on the rollers.
    When buying wire try to find precision wound reels, makes all the difference;)
     
  10. Hi Ron bin back to hosp today isnt broken just chipped a bit off wher ei broke it a year ago

    message me in a week to remind me and ill rearrange with yu

    will
     
  11. Springerdinger

    Springerdinger memoirs of the mediocre diy mechanic

    Messages:
    430
    Location:
    UK nr Southam
    Hi Ron

    Im only a rookie at this however I have had moments when the weld is inconsistant like this.
    There seem to be 3 reasons from what I have discovered
    1. contamination of the metal, could be from rust, underseal or paint residue.
    my cure has been to use a grinding wheel, rather than wire brush to get proper shiny metal before welding
    I think looking at your last picture this is probably the main reason for the problems. You have new metal going in the hole but your welding onto dirty edges from the existing metal. This will mean a poor earth and flow of current. (just my rookie experience, I may be wrong)

    2. Poor earth from the clamp or too far away from the work
    Some clamps have rounded egdes, what I do is fix a molgrip to the shiny car body where I plan to earth and then put the clamp on the molgrip, seems to work really well.

    3. Feed issues - end of a roll & jittery feed, feeding too fast, maybe the new roll is slipping, check the roller tension and sleeve condition (sleeves can be damanged fitting new reels)

    4. Power setting - too low

    As suggested grind it back, check for holes us begginers spend a lot of time filling holes

    Maybe this will help. Great thread and a tough job but keep going it does get worse before it gets better. Believe me I know

    Cheers

    Chris
     
  12. gavuk

    gavuk artful-bodger

    Messages:
    2,951
    uk wiltshire
    Try setting the wire feed with one hand on the wire speed controller,trigger the gun then wind speed up and down ,you probably need to increase the wire speed until you feel the gun almost being pushed away then reduce speed a little until you get the frying bacon sound....We had a member the other day who did have a fault with his welder ,looking at the picture with the bolt heads it was definelty working ok then..Make sure you don't have the tip too far away from the work piece ,and try on the different power levels and make a note of the rough setting so you have a startpoint next time .....keep with it Ron
     
  13. Will check the wire, it was bought perfectly wound & sealed
     
  14. Glad you are on the mend, will message u as requested.
     
  15. Thanks for your advice, worked out the molegrip trick much better grip/contact, I tried it on perfectly shiny metal at all my migs settings & still pop pop pop, gonna check how the wire is feeding in the morning.
     
  16. new tip might be in order?
     
  17. I will change that as have plenty of spares
     
  18. suzukivit1 Member

    Messages:
    7
    scotland
    thats one of the worst transits ive saw in a long time you realy got some epic work ahead of you
    colin
     
  19. schnappi Member

    Messages:
    134
    Essex
    Don't know what welder you have but 3mm plate is quite thick for some hobby welders. Maybe the welder isn't powerful enough to weld the 3mm if it's under 130amp?

    Besides that, try to make sure your wire feed is setup correctly. I've sometimes had problems with the wire spool sticking on the spool holder. I apply a little red rubber grease to the spool holder these days to help the spool turn more freely. The spring tensioner on the spool holder will stop the spool from running on so anything you can do to help the spool turn smoothly is a bonus.

    If you haven't done so already, fit a metal liner to your welder. These offer far less resistance to the wire than plastic liners and the wire feed motor has to do less work and therefore spins more consistently with less tension on the feed rollers.

    Make sure you're using the correct size contact tip for your wire and make sure the wire passes through smoothly. If in doubt, fit a new contact tip. They cost pennies and can make a big difference.

    Don't over tighten the tensioner on the wire feed rollers. Make sure you're using the correct roller for the wire you're using. What I do is pinch the wire gently at the tip between thumb and index finger and then pull the trigger to feed some wire. I then adjust the tensioner until the rollers stop slipping and start pushing the wire between my fingers. You want it so that anything other than light resistance will cause the rollers to slip.

    When welding, try to keep the lead to the torch as straight as possible so that the wire isn't having to make any turns or twists.

    Hold the torch fairly close to the work to make sure the gas is around where you're welding and so that the wire stays exactly where you want it instead of flopping around. I tend to position the torch as close as 1/4" away from the job.

    I then set the wire speed in much the same way as gavuk has already described.
     
  20. iwoo Member

    Messages:
    43
    Durham England
    Do you have a video camera or phone vid so you can youtube your welding for the experts to have a look at, do it on the bench so we can all see.

    You must have a heart like a lion doing that job, but you are approaching the job with a good spirit and willingness to take advice and not to be put off by setbacks.

    Good luck to you fella.
     
Advertisements