Thread: How thin steel can I weld with mig

Hi. I have never tried mig welding (only arc) but am gearing up for some projects I would like to take on. My problem is I can't ind any information of how thinner steel can I weld. If I had this welder (I don't, I'm just using it as a for instance) and wanted to weld mild steel tube, what is the minimum wall thickness I could weld?

http://shop.completewelding.com.au/e...oducts/CP132-1


Interestingly, most of the information on capabilities I have read has focused on maximum thickness. Considering how often I burnt through things with my old arc welder I would have though this was the more critical issue.

Thanks
Arron

Hi Aron.
Welcome to the forum.

It is not an easy question to answer as the answer is dependent on so many inputs.

There is a whole range of factors that are required give to an answer.


What is the job you have in mind?

Butt weld or fillet as in attaching a pipe to a pipe.

Diameter of the pipe.

Mig is not suited for really small diameter pipe circ welds.

Better idea!.Tell us what you hope to achieve and well go from there.

Grahame

What make/ model of stick welder do you have?
(Some can run a TIG torch which is sometimes a better option for thin stuff)

Michael

The beauty of MIG is that it's ideal for thin stuff like car body material.

Straight up (i.e. no with practice) you will probably end up blowing as many holes in the same size tubing as you do with stick.
After that its practice.

But not "blowing holes in the material" is just the beginning and while a reasonable beginners target it does not mean the weld has the correct penetration/strength etc.
It all takes practice that varies from person to person.
I've seen the odd bloke get the hang of 1mm wall after a couple of hours, most take much longer that than, and others cannot seem to ever do it.

BTW, whether it's dancing, metalwork or forgery, 10,000 hours is the generally accepted amount of experience and practice needed for most people to become expert at something.

In asking this question I was hoping to focus on the capability of the equipment, not the operator.

Presumably the operator will acquire the necessary skills in time. So let's assume that process has occurred. Now if I wanted to make this chair (I don't, but just suppose) which I expect is steel tube about 25mm OD with 1.5mm wall thickness, could I weld this with a mig?

I know I couldn't weld it with my low end arc welder, no matter how many hours I practised, but could it be done with the mig?

If not. What should I use?

IMG_1443.JPG

Originally Posted by Michael G

What make/ model of stick welder do you have?
(Some can run a TIG torch which is sometimes a better option for thin stuff)

Michael

Its a low-end unit that I acquired about 30 years ago and drag out occasionally when I need to make a mess of something. All my equipment is currently in remote storage while we live in rental accommodation - all I know is it is branded CIG.

I'm not an expert (and one of the more experienced welders is welcome to correct me/ shoot me down in flames), but I think you are asking the wrong question. I've seen some highly skilled welders do some amazing things but they have had a lot of practice and weld frequently. The tube on that chair probably could be welded with a MIG. How long it takes you to get good enough to do it is the key bit and it could be a matter of a few hours or it could take much, much longer. When I first started stick welding I would blow lots of holes in 1.6mm RHS. 20 or so years later, I don't do that quite as much

The reason I asked about your power supply is that these days inverter welders make welding a lot easier. I did this post a while ago //metalworkforums.com/f160/t200...orld-surprises. That welder is capable of TIG welding (at least the specification says so), and was not all that expensive as a second hand unit. If someone came to me with a task like that chair I would go to TIG (I do stick or TIG; no MIG) because it is so much easier to weld thin materials. TIG is slower than MIG but allows a lot more control. I remember the few times I (manually) used MIG in the workplace it was similar to stick - you had to get the travel speed right or you would get blobby joints or blow holes. The problem with welding small round tube is getting the speed and torch orientation right. If you were a robot it would be easy but for a person it takes practice and skill.

We used to use MIG for robotic welding sheet metal car parts together - certainly thinner than I could do with stick but getting the program right (ie wire feed speed and torch travel speed/ orientation) could take some mucking about.

Michael

Ok, thanks for all the replies.

So the answer seems to be that mig is capable of welding something of thin section as used in that chair.

The qualification is that it's fairly improbable an amateur like me would be able to gain the skills necessary to achieve it.

So is there no way a person of modest skill level could build that chair ?

I understand that TIG is way too difficult and specialised. So it's out.

What about oxy-acetylene ?

Braizing ?

Soldering ?

Some sort of adhesive ?

Originally Posted by Arron

So the answer seems to be that mig is capable of welding something of thin section as used in that chair.

The qualification is that it's fairly improbable an amateur like me would be able to gain the skills necessary to achieve it.

Nothing as dire as that. It's just that you would need to work at it to develop those skills. If you have good hand-eye coordination you may be able to do it with only a few hours practice. Most people however would need to put considerable time into achieving a decent result. Welding looks simple but is a skilled activity. We have people show up here wanting to weld something and disappointed that they can't pick up a torch and have it done in 5 minutes. Some persist and get there but some give it up and say they can't weld.

Originally Posted by Arron

I understand that TIG is way too difficult and specialised. So it's out.

TIG is not horribly difficult or specialised - it just needs the right equipment and (again) practice. Some people take to it like a duck to water.

Originally Posted by Arron

So is there no way an amateur could build that chair ?

An amateur could build that chair but it would require a skill level that needs to be developed. The key is how long it would take to get to an appropriate skill level. Personally I would not recommend that project for someone new to a welding process, but that is not to say that it could not be done.
I did a wood carving course once and the instructor explained that one feature of the demonstration piece we would leave until later, simply because it required better control and technique than we were likely to have straight out of the box. Rather than set us up for failure, it was left until we had a better understanding of the technique needed. We did it but after we had a few hours under our belts. Same thing applies here.

If you were local I would suggest that you come around and do some hands on to see what can and can not be (easily) done. If there is a TAFE around the place they usually do short welding courses. It may be worth enrolling to get some exposure to these methods so you have a better idea of what is required.

Michael

Hi Arron
I'm confident that anyone could weld that chair with a mig, all it takes is practice as has been said. Actually 90% of my welding is practice, the other 10% is doing the job
I think the first hurdle is having a crack at it, you might be surprised to find that it isn't as scary as first thought.
When I was an apprentice I would go in to the welding bay and cut pieces up with the oxy then weld them back together, then cut them up then weld them back together ad nauseum. Believe me, it doesn't take too long to get to know your machine and understand what needs to be done to stop blowing holes.
I used to make guards for machinery out of 1.6mm with a stick welder and found that by going vertically down it was quite easy. Looking back, if I had a mig welder the job would have been bucket loads easier.
So in my opinion, a mig would (and does) cope with thin material easily. Oh, and I am most definitely an amateur at this.

Phil

Ok, thanks.

Actually, I did do a welding course a few years back. I didn't have the facilities to practise it afterwards, so I retained almost nothing.

I should get the opportunity to try some good mig gear sometime within the next few couple of weeks.

Now I'm curious about brazing though. How does it compare to MIG/TIG. Could the chair (for instance) be braized using oxy/acetylene? From my reading I'm thinking that although the joints would be acceptably strong there wouldn't be enough closely mated surfaces to allow good capillarity? Is that right?

Hi Arron
When I braze it is more like fillet welding than say silver soldering which requires a capillary action.

Phil

Originally Posted by Steamwhisperer

Hi Arron
I'm confident that anyone could weld that chair with a mig, all it takes is practice as has been said. Actually 90% of my welding is practice, the other 10% is doing the job
I think the first hurdle is having a crack at it, you might be surprised to find that it isn't as scary as first thought.
When I was an apprentice I would go in to the welding bay and cut pieces up with the oxy then weld them back together, then cut them up then weld them back together ad nauseum. Believe me, it doesn't take too long to get to know your machine and understand what needs to be done to stop blowing holes.
I used to make guards for machinery out of 1.6mm with a stick welder and found that by going vertically down it was quite easy. Looking back, if I had a mig welder the job would have been bucket loads easier.
So in my opinion, a mig would (and does) cope with thin material easily. Oh, and I am most definitely an amateur at this.

Phil

Thanks Phil. I didn't read this before my last post. I'm looking forward to giving the MIG a go.

Getting practice is a little hard because we are unfortunately in rental accommodation at the moment and it's one of those super-neat and clean townhouses where you can't do anything. Still, if the method has potential then I'm prepared to do what I must to make it work - maybe it's time I rented a shed somewhere so I can play.

As has been said.. mig is possibly the easiest to pick up. Oxy acetlyene welding and tig are very similar. Tig is not difficult to pick up. Proficiency comes with practice on all of the above. Mig, tig and oxy acet welding can all do that chair. Also, have a grinder handy. Will be used a lot when you start out

Cheers
Mick

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