Can anyone recommend a decent MiG welder?

[Aled Dafis]

Yes, welding gas is an Argon/CO2 mix, I generally use Argoshield Llight (a BOC product) at school, which contains 5% Argon, and is generally good for welds up to around 6mm thick. For thicker metal, you'd be better off with 10 or even 15% Argon.

 

[Myfordman]

I've been very pleased with my Portamig 185. British made to order in the style of a brick outhouse.
Superb current control for the lightest of gauges up to 6mm or more in 12 steps

http://www.weldequip.com/portamig-mig-welders.htm

 

[Aled Dafis]

Yep, they're very well regarded, it was a toss up between the Portamig and the R-Tech kit when I was buying for school. In the end I went for the R-tech, as I could buy everything from them (3xMIG, 3xMMA,an AC/DC TIG, plasma, compressor etc.) and their support is second to none.

 

[Eric The Viking]

I don't get on with pub gas. My SIP 130 welder is s/h and came with an almost full bottle of Argoshield years ago, and a couple of pub bottles (CO2). Call me naive, but I didn't know about bottle rental at all. The Argoshield was great, but the CO2 was a horrible revelation - fizzing, spitting and rotten welds. I now use disposable cylinders of Argon/CO2 mix from Machine Mart (usually), but it's not as good as proper Argoshield (BOC add other gases I think in low concentrations).

Love my auto-darkening helmet - can't imagine going back to the old sort now. My welding remains pretty rubbish though.

My twopence: I found a PTFE hose liner was a great improvement. The original was nylon I think and the wire moves far better now. Also I keep the big reels in warm and dry in the house until I need them.

I've done stainless but had little success: yes I can join it, but the weld seems to have less chromium in it and thus rusts. I may be using the wrong sort of stainless wire, but I've only come across one sort at Machine Mart. Does it help if you pre-heat? I'd heard you're supposed to.

E.

 

[dickm]

+1 for keeping the welding wire somewhere warm and dry. Real faff taking it on and off, but worth the effort to ensure smooth transit through the hose.

Like EtV, I also naively bought Mig plus cylinder not realising it involved keeping BOC in the luxury to which they had been accustomed . They make the electricity compnanys look like public benefactors.

 

[stevep]

Erik there is no need to preheat stainless steel prior to welding it. You are correct in what you say about the wire, if it is the wrong grade then corrosion can occur. You will also find it difficult to weld if you are using co2, you need pure argon for the best results. The co2 could also be the cause of the corrosion.

 

[Aled Dafis]

Yes, pure Argon for Stainless and Aluminium. The range of filler wire availabe is mind boggling once you start looking into it, I have a Murex catalogue somewhere that lists all of their wire/rod ranges, it's about half an inch thick!!

 

[Eric The Viking]

Thanks chaps for that. Duly noted!

E.

 

[antarmike]

Why not a Gassless/ non gas set such as This

Best of both worlds. By being able to reverse the polarity of the Torch, one machine will change from Gasless to Gas operation.

Mind you I am spoiled running two Industrial Migs (one with spool on gun) on industrial sized bottles, 250A Tig water cooled on full sized bottle. 400A Copper wound DC MMA machine and a 250A Inverter DC MMA welder. And Oxy-Acetylene......

Using Pub CO2 is Mig welding (CO2 is inert and does not react in the weld. Metal Inert Gas) This gives poor penetration compared to using a mixed gas such as Argoshield universal where the gas takes place in a chemical reaction increasing the heat of the arc, depth of penetration and strength of the weld Using Argoshielsd is not technically MIG welding it is MAG welding (Metal Active Gas)

Although stainless can be welded with pure Argon, pure Argon is the most expensive shielding gas and better results are got cheaper By using Stainshield which is specifically designed for stainless. I would not recommend Argoshield light. BOC recommend it from 1mm metal thickness up to 5mm Max.. The BOC recommenation Of argoshield Universal is 1.6mm up to 10mm+ You lose out on performance on very thin steel, but for 99% of the time up to 5mm Universal is more capable and it can be pushed to 12mm I cannot see the point of limiting maximum thickness to only 5mm.

 

[antarmike]

After welding, stainless should always be pickled to return the surface of the welded area to a corrosion resistant state.

as here

It is never recommended to leave stainless as welded without this or similar treatment

 

[Eric The Viking]

Thanks Mike,

It makes complete sense. I knew welding removed or didn't replace the Chromium content, but I had no idea you could do anything about it afterwards!

Pickling paste sounds ideal - is it usually available from welding supplies outlets? I'll Google...

 

[siggy_7]

Using Pub CO2 is Mig welding (CO2 is inert and does not react in the weld. Metal Inert Gas) This gives poor penetration compared to using a mixed gas such as Argoshield universal where the gas takes place in a chemical reaction increasing the heat of the arc, depth of penetration and strength of the weld Using Argoshielsd is not technically MIG welding it is MAG welding (Metal Active Gas)

I think this is a little mixed up? Argon and Helium are very inert gases (they are noble gases and due to the atomic structure are very non-reactive) which means you get excellent shielding from reactions, but poor penetration. CO2 isn't as inert; you get much better penetration at the expense of oxide formation. I think active gas welding generally refers to using oxygen, nitrogen and hydrogen in controlled quantities?

 

[Eric The Viking]

Siggy is right. Welds are worse with CO2 for two reasons:

1. It *does* react to an extent. It's not inert (enough), unlike Argon (an inert gas for all practical purposes).
2. It conducts heat better than Argon, so cools the weld, arguably too much on its own.

Both are considered MIG welding, but technically only pure Argon is.

 

[antarmike]

Maybe my explanation was a bit simplistic. Argon produces a much better ionised gas which carries the arc. Argoshield contains oxygen as part of the mix. Oxygen is most definitely not inert.

The main problem with CO2 is the excessive spatter that gets ejected from the weld and the consequent time wasted cleaning up the weld area.

 

[disco_monkey79]

Just seen this thread - apologies if the following is too late to be of any use.

I have a small Clarke mig welder. Can't remember the model number, but it's non-turbo. Is the dual (gas and non-gas type). Not had to change over yet, but the guidebook makes it sound a doddle.

Not had any issues with it. It's never "birds-nested" the wire, as seems to be a common complaint with hobby welders.

My main gripe with it is - to change the power setting, you use 2 rocker switches (giving a total of 4 power settings). Inevitably, I find the best setting to be somewhere between the 4 available. If I ever buy another welder, I'll get one that sets the power via a turnable knob, to get more control over this aspect.

That said, I'm an extremely amateur welder, and someone with more skill may find no issues at all with the power settings/

 

[No skills]

I think your right TBH, I have a sip with the rocker switches at home - compared to the mig I use at work with 20 different settings its a pain in the posterior.

 

[disco_monkey79]

Glad it's not just my welding skills (or lack of them!)

 

[dickm]

Probably not relevant to many folk, but having finally decided to go the Hobbygas route, I dropped into McGregor engineering supplies in Elgin on Saturday as they are the cheaper, fairly local stockist. They were out of stock, and very reluctant to take money for when stock came in but asked me to ring yesterday to check. Rang them, sorted out the payment and the cylinder arrived in their van today. Free delivery over most of Aberdeenshire and Moray! Can't be bad - it's a 50 mile trip to Elgin.
No connection with the company, but this seems like excellent service.

 

[logan]

At last a post I can answer with conviction!!

I just tinker at woodwork cos I like it and everyone else on here seems so knowledgeable.

Welders: To start with for that budget - go with clarke. New will get you a half decent machine for that money and used mid range. Clarke a good range of hobby welders, I even have at home (like I don't weld enough at work....). If you use machinemart to buy it and your'e not in a rush, you can wait for a VAT free weekend deal and get 20% off them.

Used: always figure on new wire (don't buy cheap, you will regret it...) and a new wire liner and tips. If you will only use it occasionally, buy some tip dip too to keep the tip in decent nick between uses.

Gas arguments: Proper shield mix is preferable, will giver cleaner welds with less spatter and fewer micro inclusions, but CO2 will do for hobby stuff, not like you'll be welding the boiler on a nuclear reactor (I hope?!) as a first project. Can work out expensive on smaller bottles, I personally would go for a larger CO2 pub bottle for home work, but with the comments above noted.

Also, though get 0.8 wire and tips for hobby amp levels, should hit a happy medium with it.

And remember, the light at the end of the tunnel is almost always arc eye, so get a proper mask.

 

[DTTech]

We have a Clarke which I use occasinally, i'm not an accomplished welder by any means.

Ours has the toggle switches for the power and I concur with the comments before, i try and compensate with the feedrate which seems to help a bit.

I had no idea how long the little gas bottle was supposed to last - it was on th emachine when I started workign there - no record of it being changed and I didnt change it for ages - how are you supposed to tell? I disconected the pipe and turned it on and it makes a hissing sound. I have a new one and cant tell the difference between them - the weldgin result seems to be 'as bad' with either. I havnt notice any major splat problem (sorry, turning into thread hi-jak).

I'd say worse thing about our Clarke is the wire unspools and then kinks and then wont feed. I just cut it off and re-feed the wore/ A bit wasteful.