Any welders or auto body folks out there?

[loudcherokee]

I'm wondering if a gas-less MIG welder will be sufficient for light bodywork on a vehicle. No frame or structural welding, just sheet metal. (rust repair, shaving door handles, welding on a roll pan, etc)

Here's a link to the one I found at harbor freight -

http://www.harborfreight.com/cpi/cta...emnumber=94056

LC

[PaGunNut]

This is from the Miller Welding Company.

Solid Wire Versus Flux Cored Wire: When to Use Them and WhyComparing the advantages of MIG and Flux Cored.

Gas metal arc welding (GMAW) and flux cored arc welding (FCAW) possess different characteristics that welding operators must evaluate when selecting them for welding applications. To achieve the best results, consider the following factors: thickness of the material, proper shielding gas, wire feed speed and voltage settings, location of the work site and weld appearance. There is no "one-size-fits-all" welding solution and all of the above variables will affect the operator's decision to use solid or flux cored wire. This article will help the novice or occasional welding operators such as farmers, ranchers, motorsports enthusiasts and home hobbyists, understand the basics of solid and flux cored wire and how to maximize the advantages of each.

Solid Wire/MIG Basics

MIG power sources use a continuous solid wire electrode for filler metal and require a shielding gas delivered from a pressurized gas bottle. Mild steel solid wires are usually plated with copper to prevent oxidation, aid in electrical conductivity and help increase the life of the welding contact tip. The shielding gas protects the molten weld pool from contaminants present in the surrounding atmosphere. The most common shielding gas combination is 75 percent Argon and 25 percent CO2. While using solid wire outdoors, the operator should use caution and prevent any wind from blowing the shielding gas coverage away from the welding arc. Windshields may need to be used.

Flux Cored Wire Basics

There are two types of flux cored wires: gas shielded and self shielded. Gas shielded flux cored wires require external shielding gas and the slag is easy to remove. The operator may want to consider using gas shielded flux cored wires when welding on thicker metals or in out-of-position applications. Gas shielded flux cored wires have a flux coating that solidifies more quickly than the molten weld material. As a result, it creates a "shelf" to hold the molten pool when welding overhead or vertically up. Self shielding flux cored wire does not require external shielding gas; the weld pool is protected by gas generated when flux from the wire is burned. As a result, self shielding flux cored wire is more portable because it does not require an external gas tank.

WHAT TO CONSIDER WHEN CHOOSING SOLID OR FLUX CORED WIRE

Appearance

Many welding operators believe that weld appearance is an important factor. When you are working on materials less than 3/16 inches down to thin sheet metal (24 ga.), solid wire will produce a clean looking weld. For example, a short circuit transfer with .030-inch solid wire set at 18-19 volts with 160-170 amps and using 75 percent Argon and 25 percent CO2 shielding gas will usually produce little spatter, create a smaller heat affected area and reduce chances of burn-through. As a result, many automotive enthusiasts who specialize in bodywork or those who work with thinner applications prefer solid wire in their operations.
Location

The welder must also consider the location of the work site when choosing between solid and flux cored wire. There are certain environments such as windy locations, where solid wire or gas shielded flux cored wire cannot be used; exposing the shielding gas to wind can compromise the weld integrity. Typically the loss of shielding gas will produce porosity visible in the weld bead.

On the other hand, self shielded flux cored wire is ideal for welding outdoors or in windy conditions. The operator does not have to set up windshields to protect the shielding gases from being blown away because the shielding gas is generated from the burning flux. Since self shielded flux cored wire does not require external shielding gas, it is also more portable than solid wire. This portability is ideal in agricultural applications where field equipment can break down far from the shop. If you are welding thicker metals (16 ga. and above), self shielded flux cored wire also provides excellent penetration.

Thickness, Type of Application and Parameter Settings

Many novice operators attempt to use "a-one-size-fits-all" wire and shielding gas combination for multiple applications. The most common wire and gas combinations (for solid wire) are .035-inch diameter wire used with a 75 percent Argon and 25 percent CO2 shielding gas. When welding thicker material, however, consideration needs to be given to welding power source output, as well as welding wire diameter. If the .035-inch wire is selected for thicker materials, and the power source is one that is plugged into a 115-volt circuit, the resulting amperage output may not be sufficient to make quality welds. The chance of "cold lap" or "lack of fusion" may increase.

Attempting to use too small of a solid wire for thicker applications (such as on A-frames of an automobile), increases the chance of lower penetration in the root, and could require more than one welding pass. Misapplication of the solid wire (even though strong enough) may also not provide adequate penetration on thicker material.

Although more expensive than solid wire, flux cored wire could help you gain productivity. Flux cored wire typically has the ability to handle the welding of dirtier materials that may have higher levels of rust, mill scale, or oil. Although cleaning is always the proper method of preparing the steel, flux cored wires contain de-oxidizing elements that trap these contaminants in the weld pool and hold them in the slag coverage typically preventing the associated weld problems found when welding "dirtier" steels. Flux cored wire also increases penetration on the side walls and offers the advantage of better deposition rates (the amount of weld metal deposited in a given time period, measured in pounds per hour) when compared to solid wire. Although the operator is initially spending more on materials for flux cored wire, the savings are realized in the decreased production time.



Which is better, solid wire or flux cored wire?

Neither wire is superior over the other. They simply have different properties, which work better on certain applications. As far as performance is concerned, both types of wire produce sound welds with good weld bead appearances when applied correctly and used within the proper parameter settings. Solid wire provides deep penetration in the root and usually has little spatter. Flux cored wire has a larger ball type transfer and produces low spatter levels. In addition, flux cored wire produces a rounder penetration profile with excellent sidewall fusion.

As far as user appeal, both solid wire and flux cored wire are relatively easy to use and are ideal for novice and occasional welders working in automotive, farming and home hobby applications. Operator appeal on solid wire may be better on thinner applications because there is no slag to remove; it is ready to paint; and the weld beads may be more aesthetically pleasing.

Conclusion

The most important thing to remember is not to fall into the "one-size-fits-all" mindset. Solid wire, self shielded flux cored wire and gas shielded flux cored wire all work well provided they are applied correctly. The type of wire you choose will be contingent upon the location of the work site, thickness of the application, proper shielding gas combination and the type of equipment available. The operator should always clean the work piece prior to welding to ensure optimum weld quality and prevent impurities from becoming trapped in the weld bead. In order to achieve the best possible results, the operator must be willing to make adjustments based on the worksite variables and consider having both solid and flux cored wire available.

Just some info to help you make your decision. I know money can be tight but it may be a good idea to purchase a MIG that can use both flux core wire and solid with shielding gas.

I have a Millermatic® 140 it would do the trick.

[loudcherokee]

So, basically, the flux core wire will provide just as strong of a weld, but will make more of a mess with slag, right? And I'm guessing slag is melted metal pieces sticking to the metal or weld? something that could be chipped off with a grinder?

I dont mind the extra cleanup, since I'll be grinding the welds smooth anyways and going over it with fiberglass reinforced body filler.

Is this the only thing to be concerned about? Basically, I just need it for one project, and I don't even know how to weld yet, so I didn't want to invest a ton on a higher end machine. I plan on getting some scrap metal and practicing welds until I can get proficient before moving on to the bodywork on my project truck. Hopefully the junkyard will give me a warped to hell door or truck lid or hood to practice on.

One other question: Alot of the how to vids and tutorials I've read out there reccomend dabbing the hot weld with a cool wet rag to prevent warping of the panel and cut down on excessive heat. Wouldn't this CAUSE warping? My experience with hot metal under cold water has resulted in warpage, for example, a cooking pan fresh out of the oven ran under cool water in the sink caused the pan to warp.

I wish I would have found this harbor freight place years ago. I could have saved a ton on tools over the years.

LC

[P89]

Flux wire takes a little more juice to make it arc and you run the risk of blowing through. Once you weld body panels with argon or co2 you won't ever want to weld with flux wire.

Yes water will warp a panel.
Weld an inch at a time about a foot apart and then go back to the begining and keep spotting it in along the seam. Take your time, let it cool on it's own.

Heat sink paste works wonderful!

[ironhorse]

my son in law and i are working on a 1961 corvair. we are using a gasless mig welder. works great. he was a body man for 15 years. got mine used off ebay for $100..

[RandomTask]

Flux wire takes a little more juice to make it arc and you run the risk of blowing through. Once you weld body panels with argon or co2 you won't ever want to weld with flux wire.

Yes water will warp a panel.
Weld an inch at a time about a foot apart and then go back to the begining and keep spotting it in along the seam. Take your time, let it cool on it's own.

Heat sink paste works wonderful!

+1 to what he said, except that heat sink paste works wonderfully.
The adverb: the forgotten part of speech.

This message brought to you by the Council for Adverb Awareness.

[JP8]

So, basically, the flux core wire will provide just as strong of a weld, but will make more of a mess with slag, right? And I'm guessing slag is melted metal pieces sticking to the metal or weld? something that could be chipped off with a grinder?

I dont mind the extra cleanup, since I'll be grinding the welds smooth anyways and going over it with fiberglass reinforced body filler.

Is this the only thing to be concerned about? Basically, I just need it for one project, and I don't even know how to weld yet, so I didn't want to invest a ton on a higher end machine. I plan on getting some scrap metal and practicing welds until I can get proficient before moving on to the bodywork on my project truck. Hopefully the junkyard will give me a warped to hell door or truck lid or hood to practice on.

One other question: Alot of the how to vids and tutorials I've read out there reccomend dabbing the hot weld with a cool wet rag to prevent warping of the panel and cut down on excessive heat. Wouldn't this CAUSE warping? My experience with hot metal under cold water has resulted in warpage, for example, a cooking pan fresh out of the oven ran under cool water in the sink caused the pan to warp.

I wish I would have found this harbor freight place years ago. I could have saved a ton on tools over the years.

LC

You can generally weld heavier material with a gasless welder than a MIG of the same wattage.

Slag is the particulate matter left over from the flux after it has performed it's shielding duties. This is a by-product of stick (ARC) and wire-feed ARC welders. Everytime you start and stop welding, you want to clean the slag off. Thats what makes it a pain in the ass.

When MIG welding and using a shielding gas, there generally is no slag...unless you messed up and didn't clean the pieces enough.

The key is to wick the heat away from the weld without "quenching" it. When you localize heat in a piece of sheet metal, it wants to expand, pushing on the metal around it. When you cool it quickly, the hot spot shrinks leaving the surrounding metal compressed. That's what warps sheet metal. The heat sink stuff is good, but a wet rag is fine as long as you tack slowly and cool. A copper sheet clamped to the pieces also helps to sink heat. You can't run beads when doing quarters, just tack every 3 inches and cool with the rag after each tack. Then come back around and tack in between those and so on until the weld is complete. It might take you 5 hours but it's worth it.

Now whether you're going to butt weld or lap weld is kind of a defining factor as to how much shit you'll need to slather on. Welding an inch at a time one foot apart as a previous poster mentioned will work for a lap joint but not on a butt joint. Most body shops will flange and lap weld while the real car guys will butt weld. The butt weld will need a minimal amount of filler and can be worked in a manner that 98% of the world could not tell the panel was replaced. No matter, you always want to make a joint near an existing body line to minimize the chance of warpage. Don't go welding in the middle of a flat panel. Also, don't use a grinding wheel on your joint...use a flap disc somewhere around 80 grit. Less heat. A 3M type stripper disc will also prove invaluable.

Lastly, I buy a lot of stuff from harbor freight, but I'd think twice about buying a welder from them. Lincoln has decent hobbyist-sized welders. A welder definitely falls into the category of "you get what you pay for".

[brian]

can it done?
yeap, no problem. but if you have never glued metal together, you'll have a pretty steap learning curve.
i doubt i would buy that machine(after having not opened the link). those little guys often come with the ablity to add gas, try and hook up with one of them. start off on the flux core and then move on to hard wire.
it is a night and day difference. 0.023 on sheet metal is the shizzle.
once you go gas you don't go back.
but in reality the gasless fluxcore is like stick welding from a roll, through a mig gun.
buy a machine larger than you think you need.
once you have a welder, you'll find all kinds of things that need welded or projects that you can use if for.
metal working is not a mystery, just expensive.


after reviewing the link.
big time pass.
gasless only
two voltage setting only, high and low.
and looks like no wire control.

hit up a farm supply center. around here we have tractor supply, not sure if they're over there or not. they'll have at the least off bands that are very likey to be made by "famous" brands.
but in fact the hobart handler line is a great series of small machines, and last i saw they were not too far out of line.
the 140's are right around 5bills. pretty good value really.

[RaisedByWolves]

Go with a Gas rig, you wont regret it in the long run.


.

[loudcherokee]

Well crap. That really puts a damper on things.