Matweld 160 Amp DC Inverter Welder

  1. Matweld 160 Member

    Posts: 20
    South Africa
    Hi Guys. I`m new to tig welding and have just bought a Matweld 160 DC inverter welder. It works very well as a "stick" welder and now I would like to try TIG welding. I have got a tig torch,1/16" tungsten electrodes,THERMAMAX Flow Meter and a large pure argon bottle. I managed to source 1 KG of Mig wire (1/16" dia.) to try it on 1" Sq. X 1/16" wall thickness square mild steel tubing. My question is - What amperage should I start with and also the flow meter output flow? I`m aware that the TIG torch is connected to the (-) connection and the earth clamp to the (+) connection. I assume that the most difficult part will be to start the arc,as this is not a proper tig welding machine? I`ve read about "scratch starting",to start the arc. Any advice would be very much appreciated.
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  2. KTMMICK

    KTMMICK Member

    I may be wrong here..........somebody will tell me if I am. But my belief is you need a minimum of 200 amps. I too live in South Africa and that was the advice I was given when buying a Stick welder. Do you mean you got 1kg of mig wire or Tig rods? Be careful in South Africa there are a lot of people who call themselves welders and will give you advice and know nothing. You are in good company here though. Out of interest where did you buy the welder?
  3. Matweld 160 Member

    Posts: 20
    South Africa
    Hi There. I was told that a 160 Amp inverter welder will be sufficient to tig weld thin stainless steel plate (0.4mm). This is what we use for the combustion chambers in the gas turbines for rc jets. I also was told by a guy that 200 Amps will be too high for the 0.4mm thickness material. The 1KG of rods was TIG rods and they are 1,6mm dia. I bought the inverter from MIDAS,when they had a promotion on it about 2 months ago. While doing some research earlier today,I found out that for 1,5mm mild steel plate,they use 60-90 Amps on the dc inverter for TIG welding. I want to go ahead and give it a try.
  4. Matweld 160 Member

    Posts: 20
    South Africa
    Today was my first shot at TIG welding and I must admit that I`m impressed with my first attempt. I started off by using 60 Amps and then brought the current down to 40 Amps. The top section of the photo will show the 40 Amp setting. I also tried the angled weld and this was not that easy,because of the electrode cup size. One has to have a steady hand and I`ll get used to that as today was my first attempt. I used a 1,6mm filler rod for mild steel. The material welded on,has a wall thickness of 1,6mm and my first attempt at it,blew a hole in it. One thing which surprised me,was the fact that I didn`t have any problems to start the arc. It started immediately,every time and the machine has not setting for this. I ground the tungsten electrode to a needle sharp profile and even when it was blunt,there was no problem in starting the arc. Argon flow rate - 15 SCFH and inverter amperage - 40 Amps.
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  5. Matweld 160 Member

    Posts: 20
    South Africa
    Hi Guys. I made a holder for my Stainless Steel filler rods. Its a 1" pipe,which was tig welded onto a 1/8" steel plate. This is the first time,that I have welded a tube onto a flat surface. I used a 0,8 mm mild steel filler rod,which was from a 15 Kg mig wire roll. I paid 15 Pounds for the 15 Kg roll of mig wire. It was still sealed in its box.
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  6. Bsmith Member

    Its ok to use mig wire as tig filler rods? I'm quite new to tig too.
  7. GeorgeB pre-moderated

    Posts: 867
    London, UK
    This is very useful feedback and information, thanks, if it effectively means that HT spark start may be very nice-to-have but is far from essential (for a non-professional) if you don't want to spend as much as it costs. Did scratch start seem to damage the TIG tip in any way?
  8. Matweld 160 Member

    Posts: 20
    South Africa
    Hello GeorgeB

    There is no "scratch" starting necessary with this Matweld machine. I have been welding mild steel tubing,with a wall thickness of 1.6 mm and set the machine`s current output to 40 Amps. I then lower the tungsten electrode onto the surface and when I raise it very slightly,there is an immediate arc. No damage has occured to the tip of the electrode. Only when I let it touch the weld pool,did the tip get damaged and contaminated. I`m very happy with this machine.

    I am waiting for the STEL MAX DP 171 C inverter welder to find its way to my Workshop. I`ll have it in 2 weeks time. Its a DC machine and its current output is from 4 - 171 Amps. At 4 Amps,the output voltage is 10.2 Volts and this will work for 0.4 mm stainless steel material. It has a "pulse" setting and down slope etc. It also uses the DSP technology and this machine has a digital display. It is just very expensive and I could by 3 of the Matweld machines,for the price of this machine.
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  9. GeorgeB pre-moderated

    Posts: 867
    London, UK
    I think I'm right in saying you are using 'scratch start'! That's whether you are scratching, touching or anything similar. It's good news.
  10. shenion

    shenion Tool Pack Rat

    Posts: 7,596
    Stone Mountain, GA USA
    Sounds like it has lift start: The current is set to the a minimum until the arc is started. That way it does not contaminate the tungsten.

    HF start is needed on most AC machines to maintain the arc as it needs to be restarted on each AC cycle. On DC you can get along without it
  11. Matweld 160 Member

    Posts: 20
    South Africa
    Hi GeorgeB.

    Okay,I now understand what you mean by "scratch Starting". I`m looking forward to testing the STEL inverter. I listened to what the Salesperson said,when buying the Matweld machine and he said that it will work for 0.4 mm stainless steel. It just blew holes through it,so I purchased another machine of an OCTO brand,which started at 5 Amps and its top end was 110 Amps. It did exactly the same,even with a 1 mm electrode. Then I found out what the problem was. At 5 Amps,the output voltage was 20.4 Volts and this is way too high. The STEL machine has a voltage of 10.2 Volts at 4 Amps,which will do the job. On the 3 phase Lincoln machine,the output voltage was 13.7 Volts,when an "aircraft welder",was welding the 0.4 mm stainless sheet for me. So this was a "learning curve" for me. Low amperage MUST have low voltage and this is the secret to welding thin material.
  12. GeorgeB pre-moderated

    Posts: 867
    London, UK
    Ah, so there is a difference, then - my mistake. My basic DC inverter is unlikely to perform as well, after all.
  13. malcolm

    malcolm Administrator Staff Member

    Posts: 8,212
    Bedford UK
    Scratch start is also commonly referred to as tap start or lift start (at least by me - inverters are good at starting and don't need a scratch). The alternative for TIG is HF (high frequency) start where you just touch a button and the thing starts arcing by itself without needing to touch the work first.


    Edit - give TIG a shot George. Your Wolf should manage it and TIG is fun to do.
  14. Matweld 160 Member

    Posts: 20
    South Africa
    Hi shenion

    Thankyou for your input. This Forum has taught me a lot of things and now I know what to ask any Sales person,should the time come,when I need to enquire about a certain thing.
  15. shenion

    shenion Tool Pack Rat

    Posts: 7,596
    Stone Mountain, GA USA
    0.4mm stainless, wow.

    Bought a welding table off a guy I met. He showed me a pair of razor blades he fusion welded together with his EconoTIG. I did not think much of it until i tried it. My Airco on the 5A setting just vaporised it ;)
  16. TIG Paul

    TIG Paul Moderator Staff Member

    Posts: 3,634
    Northampton. UK
    The term Scratch start is a bit misleading, some describe the technique as like using a pencil to draw a short line or dash, others suggest using a carbon block to strike on and then moving on to the weld but all you need to do is gently touch down and then lift off a couple of mm to establish an arc, more like making a full stop with a pen, it is harder on tips than HF start but when you get used to it, its actually very easy.
  17. Matweld 160 Member

    Posts: 20
    South Africa
    Hi shenion

    What is the output voltage at 5 Amps on your machine? I believe that the output voltage is the most important factor,which one must take into consideration,when welding very thin stainless steel?
  18. Matweld 160 Member

    Posts: 20
    South Africa
    Hi TIG Paul

    Thanks for your explanation. Thats exactly what I have been doing with my Matweld machine. Have any of you guys heard of the KEMPPI 180 MLT DC inverter welder? I was offered a test on one this afternoon BUT its quite expensive here in S.A.
  19. shenion

    shenion Tool Pack Rat

    Posts: 7,596
    Stone Mountain, GA USA
    Hard to say as the volt/amp curves go to 600A.

    Looks to be around 10V. I think it is it needs to be recalibrated to my supply voltage. These type of old, transformer machines need to be calibrated on each install to set the current range.

    I later had a thought of trying it DCEP with a 1.6mm tungsten. Should have worked.

    Edit: there was an option on this beast for a 1A minimum.
  20. Matweld 160 Member

    Posts: 20
    South Africa
    Hi weldequip

    Thanks for your feedback. I joined this Forum to see if I could find any info on welding 0.4 mm stainless steel. I build model gas turbine engines and we use the stainless steel sheeting for the combustion chambers. I have realised that buying a "cheap" machine,is not the correct route to follow and one must look at the more expensive ones (thats for buying a new one and not second hand).The more expensive machines,have a low voltage at the minimum current setting. This is why I will purchase the STEL inverter and will just use it for the stainless material.
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