Mig welders
Bombardier
Joined: Mar 2007
Posts: 9,655
Likes: 607
From: Da' Dirty South
whatever is readily available at your local welding supply house. i've used argon CO2 mix, and straight CO2. this was on mild steel....
here is some information from Lincoln's website
Q: Does shielding gas affect the quality of the finished weld?
A: For most mild steel applications, CO2 will provide adequate shielding, but when you must have a flatter bead profile, less spatter or better wetting action, you may want to consider adding 75 to 90% argon to your CO2 shielding gas mix.
Why? Argon is essentially inert to the molten weld metal and therefore will not react with the molten weld metal. When CO2 is mixed with Argon, the reactivity of the gas is reduced and the arc becomes more stable. But, Argon is more expensive. In production welding, selecting the perfect shielding gas can be a science of its own. Attributes such as material thickness, welding position, electrode diameter, surface condition, welding procedures and others can affect results.
Common gas mixes for the home hobbyist and small fabricator would be:
* 100% CO2 -Lowest price, generally greatest penetration, and higher levels of spatter. Limited to short circuit and globular transfer.
* 75% Argon - 25% CO2 -Higher price, most commonly used by home hobbyist and light fabricator, lower levels of spatter and flatter weld bead than 100% CO2. Limited to short circuit and globular transfer.
* 85% Argon - 15% CO2-Higher price, most commonly used by fabricators, with a good combination of lower spatter levels and excellent penetration for heavier plate applications and with steels that have more mill scale. Can be used in short circuit, globular, pulse and spray transfer.
* 90% Argon - 10% CO2- Higher price, most commonly used by fabricators, with a good combination of lower spatter levels and good penetration for a wide variety of steel plate applications. Can be used in short circuit, globular, pulse and spray transfer.
here is some information from Lincoln's website
Originally Posted by http://www.lincolnelectric.com/knowledge/articles/content/migfaq.asp
Q: Does shielding gas affect the quality of the finished weld?
A: For most mild steel applications, CO2 will provide adequate shielding, but when you must have a flatter bead profile, less spatter or better wetting action, you may want to consider adding 75 to 90% argon to your CO2 shielding gas mix.
Why? Argon is essentially inert to the molten weld metal and therefore will not react with the molten weld metal. When CO2 is mixed with Argon, the reactivity of the gas is reduced and the arc becomes more stable. But, Argon is more expensive. In production welding, selecting the perfect shielding gas can be a science of its own. Attributes such as material thickness, welding position, electrode diameter, surface condition, welding procedures and others can affect results.
Common gas mixes for the home hobbyist and small fabricator would be:
* 100% CO2 -Lowest price, generally greatest penetration, and higher levels of spatter. Limited to short circuit and globular transfer.
* 75% Argon - 25% CO2 -Higher price, most commonly used by home hobbyist and light fabricator, lower levels of spatter and flatter weld bead than 100% CO2. Limited to short circuit and globular transfer.
* 85% Argon - 15% CO2-Higher price, most commonly used by fabricators, with a good combination of lower spatter levels and excellent penetration for heavier plate applications and with steels that have more mill scale. Can be used in short circuit, globular, pulse and spray transfer.
* 90% Argon - 10% CO2- Higher price, most commonly used by fabricators, with a good combination of lower spatter levels and good penetration for a wide variety of steel plate applications. Can be used in short circuit, globular, pulse and spray transfer.
BOMBARDIER
Joined: Mar 2007
Posts: 12,854
Likes: 1,112
From: Illinois?
For the little bit of price difference go with the Argon/CO2 75/25 mix. Makes the welds so much cleaner then straight CO2 and price difference is very little. Even makes the novice welder look good, and go with the biggest welder you can squeeze money out of your wallet to get. No matter how adequate the welder may seem now your gonna want bigger down the road.
Where your working also makes a big difference. If your gonna be welding in any kind of breeze this Mig is gonna be worthless, can't even have fan's runnin towards you cause it blows the shielding gas away. So if you have a shop they are great, if your out in your driveway look at a stick welder. I've got a 220V Hobart Mig, can't remember the model number on it that I use for shop work and a 220V AC/DC Lincoln stick welder I use for the outside stuff or over 1 inch thick material. I can weld anvils together with that thing.
I also forgot to mention it. When you buy this thing don't get suckered in on buyin a tank with it until you check around your town to see if anybody will fill the tank. We have 4 different shops in town for welding supplies and none of them will fill personal tanks anymore, only the ones you rent from them. I own the tank on my welder and have to drive 70 miles each direction to have it filled now cause they are the closest shop that will fill personal tanks. My torch tanks go dry it's a five mile trip.
Where your working also makes a big difference. If your gonna be welding in any kind of breeze this Mig is gonna be worthless, can't even have fan's runnin towards you cause it blows the shielding gas away. So if you have a shop they are great, if your out in your driveway look at a stick welder. I've got a 220V Hobart Mig, can't remember the model number on it that I use for shop work and a 220V AC/DC Lincoln stick welder I use for the outside stuff or over 1 inch thick material. I can weld anvils together with that thing.
I also forgot to mention it. When you buy this thing don't get suckered in on buyin a tank with it until you check around your town to see if anybody will fill the tank. We have 4 different shops in town for welding supplies and none of them will fill personal tanks anymore, only the ones you rent from them. I own the tank on my welder and have to drive 70 miles each direction to have it filled now cause they are the closest shop that will fill personal tanks. My torch tanks go dry it's a five mile trip.
Last edited by Uncle Bubba; May 18, 2010 at 04:45 PM.
Thread Starter
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Diesel Fan
Joined: May 2010
Posts: 14
Likes: 0
From: Northern California
yeah good point bubba.but its going to be run mostly in a shop enviroment. and im also going to be doing some fabrication work and it would be pretty difficult to get in some tighter spots with the stick.they are great welders had the same ole lincoln "tombstone".i decided ill get the miller and i will drive down to the welding supplier to check out if i can have a personal tank filled
