How much Shield Gas?

[gr8legs]

If you haven't yet made the investment let me chime in here extolling the virtues of using CO2 as as newbie welder.

Benefits: Cheap!

Tradeoffs: As noted above, there's a bit of spatter with CO2 and the weld may not look like a journeyman did it.

Regarding spatter: Easy enough to avoid - either use an anti-spatter spray before welding or get one of Freight Harbor's pneumatic needle scalers and remove the spater with it after welding. Use the spray if you're not going to paint the joint (the spray is oil based and takes extra cleaning). The scaler is the bee's knees for removing the scritchies.

Using CO2 the weld may not be as pretty. Um, yeah - you're a newbie. Your first welds will look like a dog crawled onto your metal and crapped regardless of CO2 or bi- or tr- or quad- mixtures. Learn to weld and get your experience on the cheap with CO2 - and when you acquire the technique advance to the $$$ mixed gases.

Who knows, your first 20# CO2 tank may last a lifetime and give great results after you have honed your skills.

YMMV, have fun!

Stu

 

[Boswell]

Thanks Stu. I should have everything I need for my first effort this weekend. I don't have a lot of steel scrap but enough to get some practice with.

 

[Boswell]

Well I thought I should give an update. I went with a 80/20 Agron/CO2. As predicted my joints looked terrible but I improved with practice. Here are a couple of pictures of the results. It is not a accident that I am too far away for you to see the actual weld joints Thanks everyone for your advice.

 

[westerner]

looks like a monkey's butt.

I always thought they looked like electrically popped metal popcorn. Complete with fluff, pockets and foamy texture.
I have seen it more times than I care to admit.....

 

[erikmannie]

I use 80 cubic feet (Q sized) cylinders of C25 and 25cfm, so that is over three hours of continuous welding.

 

[General Zod]

I use 80 cubic feet (Q sized) cylinders of C25 and 25cfm, so that is over three hours of continuous welding.

CFH.

Continuous, yes. With lots of starts and stops? Hell no. Lots of starts waste shielding gas due to the volume that gets stored in the hose and then PUFFS out at a much higher rate than what the flowmeter is set for. Listen carefully and you can hear the initial blast (and also feel it if you're careful enough) a lot stronger than the residual metered gas flow. The more starts you do, the more is wasted.