Thanks Thanks:  0
Likes Likes:  0
Needs Pictures Needs Pictures:  0
Picture(s) thanks Picture(s) thanks:  0
Page 1 of 2 12 LastLast
Results 1 to 15 of 18
  1. #1
    Join Date
    Jun 2010
    Location
    Belgrave
    Posts
    10

    Default problem TIG butt welding thin material

    I have a DC Kemppi miniarc 150. I usually don't tack anything thin, but I have a truck that has some panels that needs some TLC. Obviously the stick won't do .8mm panels

    So I wander off to the local Welding shop and Ralph there shows me the TIG attachment for my machine, and a little consumable gas bottle. $201 and I'm ready to go.

    Before that I ask if I can try it in his workshop area. I have some .8mm with me. He hooks up to the big gas bottle, puts in a 1.6mm tungsten rod, and off we go! We both had a go. After 30 minutes neither of us could get much of a tack. Tried and tried. I asked if going down to a 1mm tungsten rod might help. He thought it wouldn't because you couldn't get enough amps with that. Not sure what he meant there.

    Anyone use a similar unit to TIG weld thin panels?

  2. #2
    Join Date
    Apr 2011
    Location
    Brisbane
    Posts
    91

    Default

    what problem were you having getting a tack, just burning the plates away from each other instead of getting a puddle across both plates?

  3. #3
    Join Date
    Jan 2004
    Location
    Mackay North Qld
    Posts
    6,446

    Default

    The way read it the tungsten at 1mm is too big.

    For .8mm th ( 1 amp per thou) 1/2 that .5mm thoriated electrode ( for stability) and set to run at around 30 to 35 amps.

    Question though, is about the Kemppi. Will it be stable running that low.?

    Grahame

  4. #4
    Join Date
    Jun 2010
    Location
    Belgrave
    Posts
    10

    Default

    Quote Originally Posted by Corgan View Post
    what problem were you having getting a tack, just burning the plates away from each other instead of getting a puddle across both plates?
    It was a butt weld on 0.8 sheet metal. Just burning a hole. Impossible to get stitch. If it was just me, I'd see it as a skill prob. But neither of us could get it.

  5. #5
    Join Date
    Jun 2010
    Location
    Belgrave
    Posts
    10

    Default

    Quote Originally Posted by Grahame Collins View Post
    The way read it the tungsten at 1mm is too big.

    For .8mm th ( 1 amp per thou) 1/2 that .5mm thoriated electrode ( for stability) and set to run at around 30 to 35 amps.

    Question though, is about the Kemppi. Will it be stable running that low.?

    Grahame
    0.5mm electrode? Thought the smallest was 1mm.

    We were using 1.6 tungsten at about 20 amps as I can remember.

    I don't know if it will be stable. Thanks for the info. Will check it out.

  6. #6
    Join Date
    Sep 2010
    Location
    Lebrina
    Posts
    1,910

    Default

    As you no doubt realise at this point, you have picked quite a hard task.
    Cleanliness of your parent metal will be most important as any paint residue or rust etc will hamper your success. I believe that you could achieve the weld with a 1.6 tungsten, but a 1mm would probably be ideal. Make sure that your tungsten has a fine point as this will concentrate your arc more effectively, (2-3x electrode diameter is the normal taper and I would lean towards the 3x), make sure that your grind marks run parallel to the axis of your electrode. You will need to hold a very short and consistent arc length so you will need to ensure that you are in a comfortable position and that your stickout is adjusted so as to allow you to rest the cup on the work to steady yourself. As to filler wire, I would use some 0.9mm mig wire as it will melt off a lot easier than 1.6 filler rod.
    Joint fitup will need to be perfect and if possible a chill block behind the joint, (copper or aluminium as a second choice), if utilised will make your job easier.
    As you are doing body work by the sound of it why not invest in a punch and flanging tool? This is a tool that forms a depressed flange along the edge of a panel allowing you to lap the rust repair section on top of the flange, finishing flush on the surface, the punch part of the tool does just that, punching a hole approximately 5mm dia. that you then plug weld. If you do not wish to do this then you don't punch the holes.
    A lap joint will be far easier to weld and finish than a butt joint, this is the way professional panelbeaters repair such panels as it is much faster and less prone to misalignment and distortion compared to a simple butt joint.
    This link shows one.
    Cheap Flange/Punch Tool from $119.90
    Last edited by Karl Robbers; 13th Sep 2011 at 01:06 PM. Reason: Add information

  7. #7
    Join Date
    May 2009
    Location
    melbourne
    Posts
    33

    Default

    Did you change the polarity? To electrode negative?
    www.methodmetal.com.au

  8. #8
    Join Date
    Dec 2009
    Location
    broadford
    Age
    63
    Posts
    213

    Default

    just went out to the shedand butted up two .8mm (stainless) scraps and welded them together,amps 35 1.6mm rod.did you reverse polarity and switch over to tig settings?

  9. #9
    Join Date
    Jun 2010
    Location
    Belgrave
    Posts
    10

    Default

    Quote Originally Posted by danielhobby View Post
    just went out to the shedand butted up two .8mm (stainless) scraps and welded them together,amps 35 1.6mm rod.did you reverse polarity and switch over to tig settings?
    Yes. Definitely did that.

    Only difference was not stainless. Would that make a difference, you think?

  10. #10
    Join Date
    Jun 2010
    Location
    Belgrave
    Posts
    10

    Default

    Quote Originally Posted by method m View Post
    Did you change the polarity? To electrode negative?
    Yes, I did.

  11. #11
    Join Date
    Dec 2009
    Location
    broadford
    Age
    63
    Posts
    213

    Default

    Quote Originally Posted by Brendon5374 View Post
    Yes. Definitely did that.

    Only difference was not stainless. Would that make a difference, you think?
    yes,a little,but not enough to be of great concern with a tack.

  12. #12
    Join Date
    Jun 2010
    Location
    Belgrave
    Posts
    10

    Default

    Quote Originally Posted by danielhobby View Post
    yes,a little,but not enough to be of great concern with a tack.
    He had it on around 20 amps. We were both mainly burning the edges away trying to get a puddle. I got too careful and started getting stuck too often. I was just trying to tack, no filler rod.

    Have you ever tried .8 mm with a 1mm electrode? I rang the guy up again to day and said I would come over and give it another crack when he gets 1mm. He said hw ould be getting them in this week. I felt a bit embarrassed spending all that time over a 200 dollar rig. But he seemed keen to figure it out himself. Also, it is the Kemppi TIG gun, not an el cheapo and he told me it was a 1.6mm thoriated tungsten electrode.

  13. #13
    Join Date
    May 2009
    Location
    melbourne
    Posts
    33

    Default

    There's no reason why you can't do it with 1.6 electrode.

    First things I'd check is if the gas is the right one, straight argon? Flowing out of the torch correctly? Tungsten is still clean after the weld is finished? The steel is clean? Not greasy or got any sort of coating on it?

    Out of curiosity, have you tried it on some thicker material?
    www.methodmetal.com.au

  14. #14
    Join Date
    Jun 2010
    Location
    Belgrave
    Posts
    10

    Default

    Quote Originally Posted by method m View Post
    There's no reason why you can't do it with 1.6 electrode.

    First things I'd check is if the gas is the right one, straight argon? Flowing out of the torch correctly? Tungsten is still clean after the weld is finished? The steel is clean? Not greasy or got any sort of coating on it?

    Out of curiosity, have you tried it on some thicker material?
    I'm pretty sure it was straight argon. I will check.

    My intention is to buy a disposable bottle, so I hope that will be ok. It did have that light grey sheet metal coating. We sanded that off a bit.

    I did not try thicker. I have DC stick welded (tacked) 1.5mm steel with a 1.6mm stick - after some mucking about and learning and getting some touch. So in buying the TIG I only had one thing in mind and that was to weld thinner stuff.

    Question: given proper prep should it be fairly simple to tack using a scratch TIG 0.8mm sheet metal?

  15. #15
    Join Date
    May 2009
    Location
    melbourne
    Posts
    33

    Default

    Quote Originally Posted by Brendon5374 View Post
    Question: given proper prep should it be fairly simple to tack using a scratch TIG 0.8mm sheet metal?
    Sure it's doable but some skill is needed to do it consistently. The problem with the scratch tig is it's hard to get the arc in exactly the position you need after the arc has been struck. And even harder if you have a manual flip down helmet.

    A lot easier and cleaner with HF start.

    If the join has a very nice tight fit up, you might have better success actually using higher heat. I know it sounds crazy, but you can get a quick hot tack to instantly fuse the edges on higher heat without having to wait around for more heat to sink into the surrounding metal when using lower amps.

    Try putting a back up bar behind the weld like some nice thick aluminium or copper (as already mentioned) and even better if you keep it in the fridge/freezer.
    www.methodmetal.com.au

Page 1 of 2 12 LastLast

Similar Threads

  1. Welding thin rectangular tube
    By Tiger in forum WELDING
    Replies: 18
    Last Post: 20th Jul 2009, 10:55 PM
  2. Welding thin Stainless
    By pipeclay in forum WELDING
    Replies: 15
    Last Post: 12th Jun 2009, 04:37 PM
  3. Welding applications and thin metal
    By Grahame Collins in forum WELDING
    Replies: 21
    Last Post: 10th Nov 2007, 01:36 AM
  4. Welding thick to thin section RHS
    By Grahame Collins in forum WELDING
    Replies: 1
    Last Post: 6th Nov 2007, 08:34 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
  •