Inverter Welders

Discussion in 'Tool Talk' started by KIAB, Apr 6, 2019.

  1. KIAB

    KIAB Well-Known Member

    Have had enough of my arc welder, too heavy,draws too much current, so thinking getting into the 21st century with a inverter welder, anybody got one,they are smaller in size & much lighter,& use less current.
    Looked at a secondhand Kemppi Minarc 150,£285,only weighs 4kg, will do MMA (arc) upto 3.25mm rod, & TIG welding,if your buy extra torch,useful, but unlikely to use it.

    Have considered MIG, but no good outside if windy,struggles with thick material,& metals need to be clean & not rusty.
     
  2. robertpstubbs

    robertpstubbs Active Member

    I still like using oxy-acetylene.
     
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  3. KIAB

    KIAB Well-Known Member

    Love using it,as I do oxy-propane,sold my torches a few years ago, but safe storage of acetylene would be a problem here,& I dread to think of the cost for acetylene gas today.
     
  4. CGN

    CGN Well-Known Member

    Do you use it enough to warrant the change Kiab?
     
    KIAB likes this.
  5. KIAB

    KIAB Well-Known Member

    What a bargain.

    https://www.ebay.co.uk/itm/gas-welding-kit/273789744476?hash=item3fbf23f55c:g:eek:JMAAOSwJ85cofL1
    Very good question,it can vary, used it a couple of times this year,made a pair of bow top gates a few years ago,also want to do some railings,just find my present welder too heavy to lug around,needing 16A supply is a nusiance,plus inverter welder will work easily on 13A,only need 16A for the larger rods,is easier to strike a arc,no chance electrode sticking to work piece.
     
  6. Astramax

    Astramax Well-Known Member

    Used to do a fair bit of TIG welding in a previous job, so much so that I am an A1 welder, now the best welders are shipyard welders but they fall well below submarine welders who's welds are 'X ray' inspected for imperfections due to the pressure subs operate in!:)
     
    KIAB likes this.
  7. KIAB

    KIAB Well-Known Member

    Years since I've done TIG.

    The better quailty inverter welders use Siemens IGBT (Insulated gate bipolor transistor) Inverter technology, not inferior Mosfets.
     
  8. ajohn

    ajohn Active Member

    ;) I used to use a stick welder for car body work may years ago with a 1/16 stick. Cut out the rusty bit etc or even leave a bit there if solid. It was ok once the arc got going so personally when choosing I am a big fan of striking voltage. That shouldn't be much of a problem on a decent inverter welder. I also used 1/8 sticks with it, much easier as the current was set way up.

    I have used MIG, a decent one ex hire shop and still ok but I'm not a big fan. It's too easy to get no penetration. I worked at a place that did work on 1tonne vans and asked one of the people who used that regularly and he just smiled pointing out that often it doesn't matter.

    The machinemart inverters have a good reputation and TIG can be used on all of them - even the small one so I'm told even though they don't say so. I have used a huge industrial one on aluminium. It needs very low currents, tacking steel without a filler does too so as I see it the low end needs thinking about as well as high. The most powerful thing may not be the best bet as some don't go very low. I'm told it's also possible to braze with them - have my doubts though and would need more info. Going back to my old stick welder lots of people concentrated on amps, way more they would need in practice = much worse low current performance unless some one forks out for an industrial unit that will weigh many times what the usual things weigh.

    I decided to buy an all 3 in one. Stick, TIG and plasma cutter. Chinese. If you go that way best look around carefully reviews etc but people are buying and using them. :D I haven't used it yet. It should have been used last summer to make a custom dog cage for the car but kitchen and other things got in the way. I could only do work outside then as garage roof has serious problems, fixed now. Reason for buying. Last time I cut all of the mesh panels and ground of sharp edges and paid some one to tack tig it together and powder coat it. Cost over twice the cost of the inverter. The plasma cutter may not leave sharp edges saving a lot of work. Need a compressor to go with that. Also had to buy some gauges and regulators etc but they can be found pretty cheaply even 2 stage for argon. Argon is pricey. Hard to know which way to go on that. BOC do a deal for model engineers, cheapest and big bottles plus rent. Depends how much some one needs to do. Use too much with BOC and they will then say trade prices. It's not easy to get the deal anyway. Easiest for many people for odd use is probably other suppliers. Usually lower pressure in the bottles and etc as they fill up from BOC bottles.

    John
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  9. KIAB

    KIAB Well-Known Member

    When I had mig, didn't use BOC,so much hassle,it was Hobbyweld or SGS Gases, usually a mix ,like 83% Argon, 15% Carbon Dioxide, 2% Oxygen, which is Hobbyweld 15,can't remember SGS number.
     
  10. ajohn

    ajohn Active Member

    I suspect argon for TIG will always be from BOC initially who ever it's bought from. It needs to be very pure.

    John
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  11. robertpstubbs

    robertpstubbs Active Member

    The other major supplier of industrial gases is Air Products.
     
  12. CGN

    CGN Well-Known Member

    I just use c02 for mig as it’s cheap. Turn the amps up a bit, don’t be shy with the gas and you can get decent welds. Generally weld thin metal (car body) by doing short multiple welds which helps prevent distortion. Important when doing ‘restoration’ type welding as opposed to MOT welding.
     
  13. KIAB

    KIAB Well-Known Member

    Have a argon mix,can vary mix depending on thickness your welding,but you get less splatter & smoother welds, compared to all c02.
     
  14. robertpstubbs

    robertpstubbs Active Member

    When I employed a welder we just used Argoshield Universal (86% Argon & 12% CO2). But you can get Argoshield Light (93% Argon & 5% CO2) and Argoshield Heavy (78% Argon & 20% CO2).
     
    KIAB likes this.
  15. CGN

    CGN Well-Known Member

    I’m sure you’re right Kiab. All I can say is that I can get very good results with my setup. I ended up getting asked to go and work at a local garage after they saw my work, which I did for awhile. Been offered a few jobs since.
     
  16. Dam0n

    Dam0n Active Member

    I have a MIG and have never had any issues with welding even fairly thick plate outside.

    Unless you're in galeforce winds I wouldn't worry too much.
     
  17. robertpstubbs

    robertpstubbs Active Member

    I’d be interested to know how Argon is extracted from the atmosphere.

    When we use it for welding it goes back into the atmosphere.

    It seems a shame that it couldn’t be recycled and reused at the point of use.
     
  18. KIAB

    KIAB Well-Known Member

    Quote: Argon is produced industrially by the fractional distillation of liquid air in a cryogenic air separation unit; a process that separates liquid nitrogen, which boils at 77.3 K, from argon, which boils at 87.3 K, and liquid oxygen, which boils at 90.2 K. About 700,000 tonnes of argon are produced worldwide every year.

    http://argon.atomistry.com/isolation.html

    And finally...Why don't I tell chemistry jokes? All the good ones argon!:rolleyes:
     
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  19. ajohn

    ajohn Active Member

    The attraction of TIG for me is that things can be joined with just the torch and argon. No filler rod. Stitching is pretty easy but continuous welds like that are more tricky. I used to disappear behind the welders curtain at work now and again and try doing this with 6mm aluminium plate. He'd leave pieces set up for me. The catch is that it's easy to get the metal to flow and fuse but the work heats up as it's done so the speed the torch is moved at needs changing as it's moved along the weld. Same can be done with steel and I'd assume other metals as well.

    Silicone bronze filler rod can be used with it as well - any suitable filler rod in principle



    ;) Assume that like oxy acet it could also be used to loosed rusty nuts and bolts - probably more risk of melting them though

    Past some thickness in steel I feel stick welding is best and much easier to do if the arc striking voltage is high enough especially at low currents.

    If some one is using an argon and 20% co2 mix for mig pure argon works out at about 50% more going on one retailers prices. The catch against getting from BOC is the pressure in the bottles accounting for that makes BOC the cheapest, easily on the deal I mentioned. That applies to any gas and is why they can get away with their rather odd pricing policy. They even charge if some one goes to them to pick up a bottle.

    John
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  20. ajohn

    ajohn Active Member

    :D You'd need an amazing freezer to do it. I believe the same sort of technique is used to extract lots of gasses.

    John
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