I recently started using mig and read an article that if you use CO2 your weld will be sloppy. Then another article said it’s not the gas it’s that CO2 is wasted and is forced out to quickly, and you should restrict the flow of the gas with a smaller diameter gas line. Any ideas?
regarding your post title, 75/25 argon/CO2 is the 'right' gas for 95% of all mig welding. CO2 will work, Ar/CO2 will work better. you might take a look at jody's review of the little miller battery powered welder that uses paintball CO2 tanks. apparently the welder compensates for the properties of CO2 and makes the weld lay down nice.
If your MIG'n mostly mild steel then 75/25 ar/co2 is correct. If you're welding Al up to 1/4" then 100% argon is correct. I like mixing a little Helium in on the thicker Al but it depends on the size of the machine I'm using and the the grade of Al.
As far as gas hose sizes..If you're using a flow meter, the rate of flow is gauged on the amount of gas flowing out the end of the hose not how much is going into it. The hose size in your gun is determining the velocity of the gas when it exits. I prefer to supply adequate volume to the gun and then regulating the velocity by increasing or decreasing the rate of flow (cfh) at the flowmeter. I've seen burn back and clogged up nozzels when using too small a id. hose. I like a 3/8" myself.
As far as gas hose sizes..If you're using a flow meter, the rate of flow is gauged on the amount of gas flowing out the end of the hose not how much is going into it. The hose size in your gun is determining the velocity of the gas when it exits. I prefer to supply adequate volume to the gun and then regulating the velocity by increasing or decreasing the rate of flow (cfh) at the flowmeter. I've seen burn back and clogged up nozzels when using too small a id. hose. I like a 3/8" myself.
Highly skilled at turning expensive pieces of metal into useless but recyclable crap..