MIG welding Chromoly 4130

[Rrunnach]

Listen. Welding up gates and axles and using a small gas less welder does not make you an experienced welder. Sorry son, but it's you who are ignorant. Welding is a massive, difficult and complicated subject, much more than gluing a bit of steel together to keep a cow in a pen.
Take the advice given above, stay at home and drive yer tractor.

Tad harsh, Si. At least I was a bit more subtle

 

[Drains]

Tad harsh, Si. At least I was a bit more subtle

It was him started throwing the ignorant word about Terry. I though I'd try and disabuse him of his notions.

Here's some more off topic light entertainment for you, Scottish stylee. http://m.youtube.com/watch?feature=related&v=jBVTjEjyifQ

 

[hotrodder]

How high did you manage to fly those items?

Along similar lines... how many g does a gate pull when you open it?

have heard that it can be mig welded but it's generally frowned upon in the race car envoironment which explains why it's not normally mig welded??? and most sanctioning bodies will not certify a mig welded moly chassis or tubing,

I've heard lots of stories regarding the NHRA regarding their 'chromoly must be TIG welded', several of them along the lines of TIG was out of the reach of the average DIYer (at the time) and so mandating TIG only = less likely to have the properly quick/lighter cars being built by muppets

With regards to the metallurgical reasons this article is probably one of the best about on the subject... http://www.netwelding.com/Welding%204130.htm

AFAIK the EAA still favours oxy fuel and recommends that TIG welds are normalised. No idea if they'd even entertain MIG or whether anything goes as long as it meets their standards. Normalising MIG welds could achieve the same thing with regards to brittle, untempered martensite but achieving a decent standardwith regards to weld profile (fatigue resistance etc) on sub 1" diameter, sub 1mm wall thickness tube with a cheap/basic MIG ain't gonna be easy...

 

[DairyFarmer5]

The only reason I pulled the ignorance card was because "Terry" decided that I'm not "skilled" or "experienced" enough to do it! Do you know how much pressure is on a combine axle? Enough to the point where we had to put the whole combine on blocks just to get the axle back to where it needed to be. The gross weight of the combine is 10,000 lbs. and with most of the weight being in the back, where the engine is, I'd say at least 6,000 lbs. of pressure to weld that piece together. And no, the Gasless Firepower FP 120 crapped out on me two days after I posted my last post in that thread. I said screw it, I'll just use my RELATIVE'S welding equipment. Now to change subjects because I've heard enough about "YOU'RE NOT EXPERIENCED ENOUGH", do you guys know anything about the Hobart Auto Arc 130? Oh, and when I do get my welder's license in a year, what TIG welder should I get for that airplane project?

 

[penfold]

Any DC TIG set will produce a joint of satisfactory quality, even an unbranded chinese-made inverter, the ability of the operator is the critical point. This thread discusses airframe welding from a UK perspective, I would imagine the EAA website and forum would be the best place to find out about best practice in the USA.

I have no experience of the Hobart, but it looks like a decent quality hobby welder from googling it.

 

[DairyFarmer5]

See guys, penfold did just what I asked and didn't beat on me because of my "inexperience". Thanks penfold

 

[Wozzaaah]

Hobart isn't a common brand over here but from the reviews I've just read the Auto Arc 130 sounds like a decent little machine.
30-130 amps with 4 power settings, ok for anything from thin car bodywork up to around 3mm (1/8") thick.

 

[hotrodder]

See guys, penfold did just what I asked and didn't beat on me because of my "inexperience". Thanks penfold

Not inexperience, attitude. You asked for advice, didn't like what you were given so ignored it and then and came out fighting

 

[Rrunnach]

The only reason I pulled the ignorance card was because "Terry" decided that I'm not "skilled" or "experienced" enough to do it! Do you know how much pressure is on a combine axle? Enough to the point where we had to put the whole combine on blocks just to get the axle back to where it needed to be. The gross weight of the combine is 10,000 lbs. and with most of the weight being in the back, where the engine is, I'd say at least 6,000 lbs. of pressure to weld that piece together. And no, the Gasless Firepower FP 120 crapped out on me two days after I posted my last post in that thread. I said screw it, I'll just use my RELATIVE'S welding equipment. Now to change subjects because I've heard enough about "YOU'RE NOT EXPERIENCED ENOUGH", do you guys know anything about the Hobart Auto Arc 130? Oh, and when I do get my welder's license in a year, what TIG welder should I get for that airplane project?

Nowt to do with me, mate, was yon Drains fella

 

[DairyFarmer5]

Hey hotrodder, that's not advice, that's mudslinging

 

[DairyFarmer5]

Woozahh, isn't the rule for MIG welding 1 amp per 0.1" of metal?

 

[DairyFarmer5]

sorry, 0.01"

 

[Wozzaaah]

Let's all calm down please!

It can't be, that would mean 10 amps would weld 1" thick steel.

 

[Wozzaaah]

sorry, 0.01"

Not sure, I can't work in inches but in the real world 130 amps is good for about 3mm which I know is 1/8" though manufacturers will often claim their machines can weld thicker.
They probably can but not without a fair bit of joint prepping which is why I prefer to advise on the realistic side.

 

[Wozzaaah]

That still can't be right as it would suggest 130A can do 33mm, are you sure it's not .001"? That comes out at 3.3mm which is about right.

Edit: Google says it is 1 amp per .001" .

 

[shenion]

The Hobart machines are good (now owned by Miller.)

Still you are going to need to research what the weld procedures are for the application. The reason many here don't want to touch it is there are usually heat treating involved and careful control of heat levels.

I don't know what a "Welder's license" is. Never heard of such a thing. All the pros talk of is certifications and there are dozens of those.

 

[DairyFarmer5]

Certification, license, I meant the same..... There's a welding program I'm going to at a career center not far from my High School, and I can be welder certified next year

 

[DairyFarmer5]

Yeah, sorry, one more zero needs to be in there lol

 

[DairyFarmer5]

OH, and do you guys prefer Flux-Cored or Gas? I'm trying to debate whether to mess with Gas or not, it's just one more thing to worry about

 

[shenion]

Certified in what? I'd ask what you will be qualified after only one year. There are dozens of certifications.

Gas is far cleaner. Gasless wire is messy, hard to see and hear and expensive to use.