Mig, Tig, Arc, Other?

[jasonthomasfrance]

Howdy!

I'm going to be taking a welding class, but wanted to learn a bit before I go (I may have to wait for the next semester).

My friend has a mig, tried doing thin metal, but we just burn through...

What's the differences between the three?

[Tad]

In a nutshell here's the difference:

SMAW - Arc - Stick = Shielded Metal Arc Welding. Uses a consumable covered metal electrode to create the welding arc, the covering burns away and provides a shielding gas to prevent contamination and also adds some alloying compounds to the weld. Weapon of choice for high strength welds, wide variety of electrodes for specialty metals. Metals as thin a 1/16” can be welded. Can be run AC, DC+, DC-depending on electrode and purpose.

GMAW - MIG = Gas Metal Arc Welding. Uses a consumable rolled wire as the electrode to create the welding arc, shielding gas is provided by using a CO2 or CO2 mixture (sometimes Argon) to prevent contamination. Larger, 220V machines can approach penetration levels of SMAW, can be set to weld very thin metal. Limited variety of wire electrode available at reasonable cost. Smaller 110V machines have limited penetration but are very suitable for light gauge manufacturing. 220V machines can be run DC+ or DC-, 110V machines are usually not switchable.

GTAW - TIG = Gas Tungsten Arc Welding. Uses a non-consumable tungsten electrode to create the arc, shielding gas is provided by using Argon or an Argon mix (helium is also used) to prevent contamination. Filler metal is provided in the form of a rod that is inserted into the weld pool. Wide variety of uses for many metals (Aluminum and Stainless included). Can be run AC for Aluminum, DC+ & DC- for Stainless for Stainless & mild steel. Metals as thin as beer cans and as thick as SCH 120 pipe can be welded with this process.

Terms to remember:
Arc length = the distance from the metal to the electrode (closer distances provide a cooler more stable arc).
Duty Cycle = The amount of time a welder can be used in a 10 minute period (60% duty cycle = 6 out of 10 minutes)

Your burn through problem with the mig welder is solved through a combination of:
The correct heat setting
The correct wire speed setting
The correct speed of travel (how fast you move)
The correct arc length (the distance from the metal to the electrode)

[jasonthomasfrance]

Whoa! Too cool! Just what I was looking for! Good info! Do you teach this or something? :D :D

[Tad]

I’m a high school welding teacher, sorry, I left out flux core and oxy-fuel welding but I’ll post more later when I get back from Mexico Sunday.
Happy Welding

[jasonthomasfrance]

Yeah, I caught that from a previous posting of yours. *smile* Have fun in Mexico! That's for the info. Can't wait to take the class. Make my own bumpers. Mmmm... bumpers...

[OBX-AUTOMOTIVE]

TADSAL.... JUST TWO THINGS...FIRST THE DUTY CYCLE.... ..HEHEHE WHEN WELDED ON STOCK CARS IN MY YOUNGER DAYS...YOU COULD KISS THE DUTY CYCLE GOOD BY ON THE OLD...AC.... 225 AMP, 220 VOLT LINCOIN WELDERS....I WOULD BURN THEM RODS AS FAST AS YOU COULD PUT THEM IN THE HOLDER..... ...AND AS FOR THE NON- CONSUMABLE TUNGSTEN HEHEHE...I WOULD ALLWAYS GET ALUMINUM STUCK ON THE END OF THE TUNGSTEN...GRINDER TIME,SHARPEN,SHARPEN,SHARPEN,.... ..MORE CLASS TIME FOR ME!!!! smile.gif :D

[jeepbob]

LOL GARY, I DO THE SAME THING WITH THE TIG.
BTW the best flowing welding rod for doing sheet metal work with an Oxy/cetylene torch is old metal coat handers. They are mild steel, don't splatter, flow well, and if you get uniforms from a uniform service they are free. In fact most guys that get uniforms usually have an overabundance of metal hangers. So many that they get thrown out. I built my old cherokee pick up cab using hangers and a torch. After 15 years of hard wheelin the welds were all that was left of the cab.

[chrisnsarah]

Wow, my wife has all those hangers from her drycleaning. Good recycling tip. Also I have a miller dialarc 35-300A welder that I got for free recently from a HS shop class that was upgrading equipment. Wondered where I could get an owners manual for it. I've been practicing running beads and lap welds-but still need more practice to weld anything practical.

[Tad]

chrisnsarah,
Almost all manufacturers have their owner manuals online and available for download now, yours should be here:

Miller Owner Manuals (http://www.millerwelds.com/main/products/owners_manuals/)

If not you can order a printed version from them.