MIG Welding. (Gas or Gasless?)

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Daydreamer

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I need to do a number of bits of welding on an old vehicle I am attempting to restore. Mostly its on light steel 1mm sheet but up to about 3mm heavier stuff. In the past I have hired or borrowed a welder and the gas but this little project is going to take some time. I have used both CO2 and Coogar (the difference is noticeable!). I don't mind buying a smallish welder but I really don't want to be bothered with the frig of hiring gas cylinders. There are a bewildering number of different makes and capacities available but I am considering this Clarke machine.

http://www.toolclick.co.uk/p/clarke-no-gas-mig-welder-135-amp/1265

Does anyone have an informed opinion on this device and if not this one then what else might be worth considering?

TIA
 
If you aren't a perfectionist, get hold of a pub type CO2 bottle and adjustable regulator. I've been told that a diy warming coil between the reggy and tool improves the weld. Gasless seems to be pretty feeble.
 
Daydreamer said:
I don't mind buying a smallish welder but I really don't want to be bothered with the frig of hiring gas cylinders.
Click to expand...

With the Clarke MIG welders (and presumably other similar types) you don't hire gas bottles, you buy disposable ones about the size of a 1-litre pop bottle that strap onto the back of the machine. They sell CO2 and argon and I think a couple of other types.

I believe the "no gas mig" uses special wire with stuff in the middle (bit like flux-cored solder) that flashes into gas from the heat of welding. Not tried it, but I find the idea of a proper adjustable gas shield more convincing.

The only welders I've used are Clarke ones (plus a huge old industrial stick-welder for a couple of evenings on a course) so I don't have much to compare against - but I find the basic MIG one quite acceptable for my simple needs. The low-end stick-welder which I bought first lacks voltage for striking the arc, which is a real pain for the beginner who needs all the help he can get, so I wouldn't recommend that.

Pete
 
Don't use gas less, welding 1mm old car bodywork is hard enough and I havnt seen a tidy gas less weld yet. A well set up mig with a pub gas bottle is your best bet as the little bottles cost a fortune when you add it up. Boc do a small gas bottle of argoshield which is pretty good and bottle rental was only about £18 a year, remember it's all in the prep, the welding is the easy bit.
 
Buy a decent welder if you're going to work with 1mm plate.Cheap ones may not give you the low amps you'll need.Get a pub bottle ,better and cheaper than gasless.CO2 is not ideal for thin plate because it gives too much penetration but with a bit of practice it's very usable.Avoid heating the area too much and push the gun .I find that the best way to weld on thin plate is to push the gun and then quickly move it back into the puddle, then forward,back and so on. If you're holing the base metal ,do it in pulses always overlaping the welds.
I got this one as a back up and now use it all the time .A real gem
http://www.r-techwelding.co.uk/mig-welder-r-tech-i-mig180/
(hope they'll give me a commission:))
 
paul-essex said:
most motor factors now rent 15 lt bottles for a deposit plus price of gas when finished sell your welder and return the bottle I would not use less than a 150 amp welder with a euro torch
Click to expand...

I rented CO2 from BOC for a while- it becomes expensive. I found "Hobbyweld" gas through the local MotorFactor.
You pay a deposit and a fill. No rental costs ongoing. When you want to turn in the bottle for good you get your deposit back. Much better than BOC which is geared to business level consumption of gas.
 
I have a similar Clarke MIG machine and it's adequate. The only major disadvantage is that the current is only adjustable in 6 undefined steps (min,max x 1,2,3) rather than via a simpler dial.

Forget gasless MIG. The only advantage over SMAW that I can see is the gun and wire feed brings you closer to the work, but you still have all that slag to deal with and the filler wire is only available in limited flavours whereas SMAW electrodes are available in all types and sizes. Cutting the SMAW electrodes into sections brings you closer in to the weld pool.

Disposable MIG shield gas is only readily available in the 3 types/mixes (pure CO2 or Argon, 85/15 Ar/CO2) and you can't get the mixes like 96/4 or tri-mixes with helium that you really need for quality stainless welding. The costs are high too; think £1/minute of welding and you won't be far off.

All that said MIG with disposable gas is OK for the hobbyist and my boat is held together with pieces of my own work (chainplates for example), but I'm not sure that I'd fancy working on thin car bodywork with it.

For everything that you ever wanted to know about MIG search out ChuckE2009's videos on Youtube, he's a star.
 
+1 for NOT using a gasles MIG. I use a conventional single phase MIG. It's a "Murex" (BOC's own brand). I'd always prefer to buy a second hand semi-industrial machine than a brand new "DIY" machine. They seem more durable. I get my welding gas from Adams gas.

http://www.adamsgas.co.uk/hobby-gas-welding

The gas is expensive, but there's no rent on the bottles. I had one several years before I needed to replace it and they were happy to exchange it when I did.
 
Don't bother using gas less. I have a hired Argon gas mix bottle that I have been using for my car restoring. The throw away bottles will not be enough and will be expensive. In Australia now we have just started to be able to own our own bottles and while this is expensive initially it's the way to go. I have a full Argon bottle and I'm able to weld aluminium which is very handy and surprisingly easy. I will finish off the Argon mixture bottle and return that and just use straight Argon for mild steel as well.
 
Look at this website for loads of good advice and information http://www.mig-welding.co.uk/ look at the tutorials especially thin metal technique
I would go for the gas option.
A gasless mig will be hotter so not so good on thin metal but won't be affected by wind so much if used outside. Clarke welders are thought to be a reasonable starter mig but there are several models to chose from and I have heard that some are better built than others.
I have heard several bad reports of cheaper end SIP welders having wire feed problems.
As stated look for something with low minimum power setting (this is where most cheap mig welders fall down)
I agree with Avocet I bought a new Clarke 100E and used it for years, then I decided to replace it and bought a much larger used Cebora mig from a body shop that was closing down, the Cebora is a much nicer and easier machine to use.
I used to get my co2 bottle filled by the mate of a mate who worked for a fire extinguisher company but this source dried up so I rented a bottle on a 5 year lease and then just pay for refills.
Pete
 
Hi.
If you are welding thin sheet. You have to use gas. Forget using co2 is all just a bodge. You want a 150 amp machine minimum. ..then it will do most things you need....even thicker stuff.
Get a hobbyweld cylinder £50 deposit and get one filled with a trimix (argon, co2, oxygen) and you have half a chance of doing a decent job.

http://www.hobbyweld.co.uk/products/

I have a co2 bottle here and a trimix....the difference on thin sheet is enormous.
Otherwise just get someone to do it. Don't listen to anyone else. This is the only way to do it without making a crappy mess

Good luck.
 
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pete said:
Look at this website for loads of good advice and information http://www.mig-welding.co.uk/ look at the tutorials especially thin metal technique
I would go for the gas option.
A gasless mig will be hotter so not so good on thin metal but won't be affected by wind so much if used outside. Clarke welders are thought to be a reasonable starter mig but there are several models to chose from and I have heard that some are better built than others.
I have heard several bad reports of cheaper end SIP welders having wire feed problems.
As stated look for something with low minimum power setting (this is where most cheap mig welders fall down)
I agree with Avocet I bought a new Clarke 100E and used it for years, then I decided to replace it and bought a much larger used Cebora mig from a body shop that was closing down, the Cebora is a much nicer and easier machine to use.
I used to get my co2 bottle filled by the mate of a mate who worked for a fire extinguisher company but this source dried up so I rented a bottle on a 5 year lease and then just pay for refills.
Pete
Click to expand...
I would second most of Pete's comments.
However, I consider 1mm to be thick sheet for a car and could weld it perfectly well with CO or gasless but in the day I could also do so with a stick welder!
Gasless is a cross between cored solder and welding sticks; The finished weld has a scale that can be knocked off, though thinner than a stick welder will produce so it can be left if you are so inclined. The big advantage is that it is easier to use outdoors and the welder itself becomes a little more portable.

The cost of the gas is offset by the increased cost of gasless wire and the wire consumption will of course be greater.

You will find a proper industrial welder much nicer to use than a hobby one. Maybe you can hire one?
 
mattnj said:
Hi.
If you are welding thin sheet. You have to use gas. Forget using co2 is all just a bodge. You want a 150 amp machine minimum. ..then it will do most things you need....even thicker stuff.
Get a hobbyweld cylinder £50 deposit and get one filled with a trimix (argon, co2, oxygen) and you have half a chance of doing a decent job.

http://www.hobbyweld.co.uk/products/

I have a co2 bottle here and a trimix....the difference on thin sheet is enormous.
Otherwise just get someone to do it. Don't listen to anyone else. This is the only way to do it without making a crappy mess

Good luck.
Click to expand...

I would agree with most of the above.
Apart from, I bought a 100 amp MIG years ago and it's been fine for welding thin car metal, and even some of the thicker sections so in my view 150 amp isn't necessary, although that may be all you can get these days.
For clarification on the gases used and their individual characteristics:
CO2 is cheap, and gives good penetration for mild steel. But using just CO2 on its own doesn't give very good results because:
Argon is much better. It's a noble gas so doesn't react or form compounds, it's the ideal shielding gas where you're trying to keep out the oxygen and nitrogen of the atmosphere from reacting with the arc. Using argon gives a much smoother weld, easily controlled especially for the hobby / occasional welder and most importantly, where the parent metal isn't always in the best condition and can be quite thin because of corrosion.
Ideally from my experience you want a 5 to 8% CO2 in Argon. The bit of CO2 gives arc stability and a bit more penetration and heat without increasing the weld current. I have used 20% CO2 in Argon (designed for mild steel welding) but found 8% was actually better.
The weld gas mixtures containing a bit of Oxygen - I haven't used them but I do admit to a bit of a prejudice against them.
The purpose of ther shielding gas is as I said above to keep out the O2 from the air.
So why put in a bit of O2 in the shielding gas? The answer lies in the way the shielding gases are made (or rather separated).
Argon, which makes up 0.93% of air, is extracted an air separation plant, is hard to separate out because its boiling point is very close to that of Oxygen. So in the distillation column the first pass comes off contaminated with some oxygen - this is called raw Argon.
Pure Argon is achieved by reacting the remaining oxygen contamination with some Hydrogen, but this is an extra process so pure Argon costs a bit more than raw Argon. Cheaper supppliers use raw Argon (contaminated with some oxygen) and pass it off with marketing that claim it helps give better penetration, or conveniently don't mention what it does at all..
At the end of the day it's your call, each to their own but if you know the background it can help you make more informed decisions.

Argon is quite expensive compared to CO2, for good reason when you see how much energy it takes to extract it from the air and then purify it.
In order to separate the different air components they liquify air by compressing and cooling it down to around minus 200 degrees C. Think just how much energy is required to do that on an industrial scale, that's why air separation plants are always located right next to power stations.
 
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Your profile doesn't say where you are but in North Wales/Cheshire you could use the Bumble Bee garage in Connah's Quay. They sell all types of gas at very reasonable rates - I buy argon there for TIG welding but they do all industrial gases.
 
Trundlebug said:
I would agree with most of the above.
Apart from, I bought a 100 amp MIG years ago and it's been fine for welding thin car metal, and even some of the thicker sections so in my view 150 amp isn't necessary, although that may be all you can get these days.
For clarification on the gases used and their individual characteristics:
CO2 is cheap, and gives good penetration for mild steel. But using just CO2 on its own doesn't give very good results because:
Argon is much better. It's a noble gas so doesn't react or form compounds, it's the ideal shielding gas where you're trying to keep out the oxygen and nitrogen of the atmosphere from reacting with the arc. Using argon gives a much smoother weld, easily controlled especially for the hobby / occasional welder and most importantly, where the parent metal isn't always in the best condition and can be quite thin because of corrosion.
Ideally from my experience you want a 5 to 8% CO2 in Argon. The bit of CO2 gives arc stability and a bit more penetration and heat without increasing the weld current. I have used 20% CO2 in Argon (designed for mild steel welding) but found 8% was actually better.
The weld gas mixtures containing a bit of Oxygen - I haven't used them but I do admit to a bit of a prejudice against them.
The purpose of ther shielding gas is as I said above to keep out the O2 from the air.
So why put in a bit of O2 in the shielding gas? The answer lies in the way the shielding gases are made (or rather separated).
Argon, which makes up 0.93% of air, is extracted an air separation plant, is hard to separate out because its boiling point is very close to that of Oxygen. So in the distillation column the first pass comes off contaminated with some oxygen - this is called raw Argon.
Pure Argon is achieved by reacting the remaining oxygen contamination with some Hydrogen, but this is an extra process so pure Argon costs a bit more than raw Argon. Cheaper supppliers use raw Argon (contaminated with some oxygen) and pass it off with marketing that claim it helps give better penetration, or conveniently don't mention what it does at all..
At the end of the day it's your call, each to their own but if you know the background it can help you make more informed decisions.

Argon is quite expensive compared to CO2, for good reason when you see how much energy it takes to extract it from the air and then purify it.
In order to separate the different air components they liquify air by compressing and cooling it down to around minus 200 degrees C. Think just how much energy is required to do that on an industrial scale, that's why air separation plants are always located right next to power stations.
Click to expand...

Thanks. That's a useful post! My experience of it is that the argon seems to retain the heat a bit better. My Murex is only rated at 150A, and although it's fine for anything I'd want to do on a car, it was struggling to fuse 5mm thick sections for my boat cradle! It seemed better with Argon than CO2 for heavier gauges of mild steel.
 
Many thanks for the many replies which do show a remarkable consensus of opinion. So, gas it has to be. I discover I have a Hobbygas depot 2.74 miles away so that's fine.

I'm not sure whether or not to be grateful for the link below from 30boat
http://www.r-techwelding.co.uk/mig-welder-r-tech-i-mig180/

That does look like a very nice bit of kit ....................... You just know it will be nicer to use.
 
Daydreamer said:
Many thanks for the many replies which do show a remarkable consensus of opinion. So, gas it has to be. I discover I have a Hobbygas depot 2.74 miles away so that's fine.

I'm not sure whether or not to be grateful for the link below from 30boat
http://www.r-techwelding.co.uk/mig-welder-r-tech-i-mig180/

That does look like a very nice bit of kit ....................... You just know it will be nicer to use.
Click to expand...

It's obviously up to you but I've had nothing but excellent service from them and the machines perform very well. This MIG welder in particular is a joy to use. The only thing I should mention is that it only takes 5Kg reels that are more expensive per weight than the 15kg ones.If you're not doing a large amount of work the compactness may be worth it.The alternative is their next model which is more powerful and takes the large reels but has otherwise very much the same performance.
I just made a carrier for a 15kg reel and connected it to the roller feed by a bowden cable outer.
 
Gasless MIG sets should come with an angle grinder.

Gasless is excellent for use outside on a windy day but, to be honest and joking aside, gas (BOC argoshield is my preferred mix and available in hobby size bottles) will yield the best results and the cost difference is negligible over gasless. You may want to try a few different gases to see what you prefer. I was advised to try argosheild by a professional welder and must say it gave me good results.

Keep an eye on the wire feed. I have had 2 Clarke welders and both suffered from slipping wire feed. However, I believe the newer ones are a lot better. Keep them clean and make sure the wire you use is rust free (the main problem with the occasional hobby use) and it will give you hours of fun.
 
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