Mig Welding that look like tig

No shit...

If you are going to call yourself a welder (of any type), the ONLY thing that really matters is whether or not YOU can be sure that your setup and technique will deliver 100% penetration on every joint, every time...without X-rays, laser cutters, dilithium crystal dye testing or whatever the fuck.

If you are going to weld anything that is going out on the road, esp. for a customer, you'd better BE sure of that.

And don't grind the whole weld out trying to make the shit smooth!

DAMN!

 

http://www.profabricationtechniques.com/welding/mig-welding/


Hey check this website out very simple and informative

 

for sure, i see hairline cracks on grounded smooth welds all the time. they look good, but if not beveled pr penetrated good enough its all for not, and more importantly a hazard. nothing wrong with a good looking row of nickles...

 

That pic on page one looks great to most and its not bad by all means but its not a 100 percent great weld either. With experience you learn how to carry a solid core bead and make it look like a closer set of as called "stacked dimes" which should lay down flat and not really stack and pull apart (thin) as pictured. I am referring to this mig weld post.

 

Some of my mig from work today

 

Looking good
Not bad for a first post either.

 

In my shop we have to learn to mig weld on nasty sheetmetal because people want us to do stuff like shorten bedsides and not disturb the patina ( that means rust) So we just pick up crap off the floor and get things going. Here is a bedside with 8 inches removed and mig welded back together so it was not so noticeable and keep the patina ( rust) No bondo or filler just a dusting of color close to the old finish over the joint.

 

I work for a company that makes suspension for muscle cars n hot rods

 

Thats pretty amazing! Are you pushing or pulling to do those ?

 

Interesting thread, the thing is none of the major oil companies and engineering firms won't allow MIG welding (hard wire) on anything without special permission. Its wonderful that you can now buy a mig welder at the local home improvement store and can get a decent looking bead and this would be fine if it was sheet metal. Granted your frame might have more weld than factory but check out the design. Automakers use a lot of lap joints where a hot rod uses a lot of butt an fillet welds.
The thing is with hard wire mig lack of fusion is the problem and even experienced welders get it. It takes clean metal and the proper bevel and you need to be able to adjust the machine. A flux core weld with gas would be light years ahead in strength due to the flux allowing the weld to anneal.
Now lets talk about fillet welds, a proper fillet for a bracket etc. should be a least the thickness of the thinner member. Think triangle when you think about thickness, the size of both legs should be equal and a convex bead would be better than a concave one.
For the pipeliner's you could weld downhill.. it's your car your procedure.
The thing is if your just starting out, take a class. Learn how volts affect your weld. Learn how to prep your part the right way. Learn how to adjust your machine and work on it. Hard wire welding chassis parts with mig is taking a chance. Sooner or later something's going to break, someone's going to get hurt and it's going to affect the hobbie.
The photo's are a 33 my buddy and I are building we used mig to tack it and tig welded the rest. The headers were welded with mig wire using tig E-70s-6.
FTF / Lifetime Member AWS
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Level II RT,PT,MT, Film Review
Welder

 

Weaving is a basic taught during weld certification training, a lot of what we do on cars just doesn't qualify. Weaving is meant for a multi layer weld on heavy material. If you can't get it down, you'll never certify on a 5 or 7 pass weld. Once you've learned the technique on heavy material with good penetration, you can apply the technique on lighter stuff.
it's easy to get sidetracked trying to achieve a look and start screwing up torch angle and penetration if the welder doesn't have experience and discipline.
I've caught myself doing it, ground out the weld and started over.
Its tempting to lay the torch over, pull the weld so you can see it and basically just spray a bead on the surface and have shit penetration.
I keep .023 in my welder because I do mainly bodywork at home, if I need a larger weld I'll weave with proper push technique to achieve one. Not the best practice, but it happens.

 

I whole heartedly agree. when I was welding for the U.S NAVY everything we did was to XRAY SPECIFICATIONS AND THEN THERE WAS XRAY CERTIFICATIONS TO NEUCLEAR SPECIFICATIONS.

do it right the first time or DONT EVEN TOUCH IT.

 

This Lincoln link seems to keep "penetration" and "fusion" somewhat separate.
http://www.lincolnelectric.com/en-u...heory/Pages/weld-fusion-weld-penetration.aspx

yeah, the place I've worked for the last 7 years or so makes powerplant boilers and other equipment. They have a BUNCH of manufacturing and fabrication standards. Until recently they forbade MIG welding. The fear of lack of fusion was behind it. They accept it for some things now, but there is a bunch of process and operator qualification required. Their full time welding engineer said he could tell the "good" MIG welding from the "bad" MIG welding by the sound, but not by looking at the finished welds. The difference could be a fairly small change in settings.
I think the "short circuit" MIG was the one prone to cold laps and poor fusion.

Back in the early 80s we did some engine work for this guy.
http://corvetteregistry.smugmug.com/Cars/Corvette-Winners/i-ZcKSzkP
He did a lot of his own engineering, design, fabrication, engine assembly etc.
I remember him saying he had had problems with MIG welded parts that looked great, but in fact lacked fusion.

 

My 15 year old Lincoln flux core MIG is still going strong. I keep meaning to install the gas kit to make it a real MIG.
One "advantage" is standard flux core uses DC electrode negative, or straight polarity. That is the opposite polarity to MIG.

2/3rds of the heat is released at the Positive pole and 1/3rd heat at the negative pole.

EN/SP tends to make "deeper" welds with 70% or so of the heat being generated in the workpiece.
Gas shielded MIG uses EP/RP, so much less heat is developed in the melting the workpiece than melting the filler.

 

I just finished reading the two posts about M.I.G. welding boiler bodies together. to start off with stationary boilers used for hearing a commercial facility and supplying steam for various operations if the place is a hospital there will be a laundry for linens and gowns and other things including uniforms for staff and pressed garments will require steam for pressing and then there are commercial laundries that have boilers for steam presses of different types and use steam to remove stains.
those boilers are what are considered low pressure boilers the maxium working pressure on units like this typically do not exceed about 250 psi because that is really all that is needed. in the beginning steam powered ships had an operating pressure of about 200 psi to 300 psi. as time went on and shipping went from replicating engines to turbans similar to a jet engine the steam was considered saturated steam and was not powerful enough to spin the turbans. then another pass was developed to dry the steam out and that was called superheated, from there it did a better job. when the pressure is increased by superheating the construction of boilers had to be able to handle the higher pressure. that required different alloys to create a stronger material to handle what the more powerful boilers were putting out.
with that requirement along with the new alloy material a compatible filler material had to be developed with a flux either it being a industrial gas or a combination of certain elements and chemicals to coat a welding rod that will hold all the parts and pieces together and not fail.
now with that said, depending on the application of the boiler and the material that the mechanical engineers and the metalurgest have decided on also determines what the filler metal and the procedure of welding that will give an end results that will not allow catrophic failure. there is a lot of distructive testing that takes place in different laboratories to come up with the right combination.
this my opnion on this matter. I used to weld on 1200psi superheated boilers for the navy and perform stress relieving to arrange to molicules in the metal to conform with the base materials that they are attached to.

 

Isn't a gasless "Flux core mig" kind of a contradiction of terms?

If you have no gas, you haven't got the "i.g." in MIG at all.

 

We all use welding to build our cars, but what does detailed welding of boilers have to do with traditional hot rods and customs?

 

Good question.

I used to weld the ballast tanks on nuclear submarines. None of that translates to welding on a car.

 

As far as I'm concerned, Bernie knows very little about what he likes to write thousands of words about. And most of the time he can't even spell what he is trying to write correctly.
Most of what he writes is just wrong technically.
He likes trying to convince us of his knowledge and how good he is or used to be.
Just like way back when he was trying to convince us that he owned the original mold that produced Dan Woods "Milk Truck"
I think he should stick to writing stupid welding stories containing stupid acronyms for Rat Rod magazines

Many of us have done plenty of very technical types of welding but you are correct, what does it all really have to do with what we do here, other than serve as a basis for skill development.