Time for me to grow up...

RobMcBee

RobMcBee

Slow n easy when you're not gettin greasy....
Joined
Jan 12, 2009
Location
Fort Mill / Indian Land SC
..... for years now I've been welding with flux core. It has served me well but I think its time for me to graduate to gas. Not ever having bought shielding gas before, I knew coming here someone would be able to answer a few questions for me....

  • I don't do a lot of "heavy welding" mainly thin stuff. 1/16 - 1/4 max. What would be the best gas for me? 90/10 or 75/25
  • What kind of cost am I looking at for a bottle?
  • How long should I expect a bottle to last me? (weekend welder)
 
I just asked this a couple weeks back. I can only answer the cost part. Most people recommended northern or tractor supply for the gas because of convenience. A couple recommended Roberts gas which was $105 less for the cylinder. Exchange rates were comparable. That's where I got mine since it's about 3 miles from me. I priced out 80cf tanks since that's what most people use.

Most people recommend c25 for the kind of welding we do.
 
75/25 argon co2, how long it lasts depends on how much you weld and tank size. Get the biggest tank you can afford to buy. Probably somewhere in the 150-200$ range, but typically should be less than $60 to exchange it there after. Shop around for who sells and exchanges tanks local to you. Air gas, machine and welding, praxair, car quest, tractor supply, northern tool etc. Also look at the store hours. If you are doing a lot of weekend work, may want to deal with someone who is open on weekends. Fwiw I have a large tank and a smaller tank, each on different welders, with hopes they don't run out at same time. Machine and welding has always been very good and friendly to deal with but I've heard praxair has very competitive pricing.

My tanks usually last a couple months of light weekend welding, down to maybe two weekends of non stop welding.
 
An average shielding gas flow rate is 28 cfh for non environment controlled areas.
Just for example, a 90 cubic feet tank would last around 3 hours of actual weld time.

So depending on your machine, let's use a duty cycle of 30%, you can only weld a max of 3 mins out of every 10. So for every hour you may weld a max of 18 mins.

Think about how much time you actually spend welding and you can figure out how long your tank will last on average.
 
Running inside, where the airflow is less, you can dial that back even more. I routinely run around 15-20 cfh. Important tip, though: Always turn off your gas at the end of the day! Nothing worse than getting down to weld and finding out you've got a leaky regulator or solenoid and the bottle is empty. Out of habit, I always purge the line. I feel it helps with the longevity of the regulator and solenoid. Thoughts, @Mac5005?
 
@catfishblues. That is very good practice and an excellent point. In a semi controlled environment, you can decrease flow until obvious signs of contamination and then turn it up slightly. Wind and weld position mainly affect gas flow numbers. 75/25 is heavier than air and flow should be increased for overhead. Not only does purging keep the regulator diaphragm in good shape longer, it also forces you to open tank each day and set the proper flow. 10 degrees temperature change change the flow rate on a half full bottle almost 10 Cfm. I've seen several bottles at the school shop go empty due to leaking miller gas solenoids.

Very good points @catfishblues
 
On another note, I've seen guys crank the flow up stupid high to get better shielding. Like the shop fan going and trying to keep cool or a slight breeze. Either one sucks, but add a poor approach angle and you get a siphon effect and horrible shielding characteristics. So what does the feller do? Turn it wide open. Same results, but now I can hear it across the way from him! So its time to ask questions and investigate. What a mess of junked up parts.
 
thanks guy's... a lot of good info here. I will be inside mostly. I was finding a lot of different prices but it looks like Northern is probably gonna be cheapest for me.
 
I run 75/25 and a brand new 80cf full bottle cost me $279 I think it was. World of difference from flux core. Some of my buddies that weld for a living use flux core wire with gas but they are welding really heavy shit. I think the guy said it was like 50 some bucks for a fill on the bottle. I have been practicing as of late and really getting some killer looking beads.
 
Jake. said:
I run 75/25 and a brand new 80cf full bottle cost me $279 I think it was. World of difference from flux core. Some of my buddies that weld for a living use flux core wire with gas but they are welding really heavy shit. I think the guy said it was like 50 some bucks for a fill on the bottle. I have been practicing as of late and really getting some killer looking beads.
Click to expand...

where did you get your bottle?
 
I turn the gas flow up enough so when i breath deep I can still see straight.
 
@RobMcBee I'm not sure if you have a 110v or a 220v machine but in case others are reading this too. Keep in mind that some guys with 110v machines are able to get decent penetration with flux cored wire on materials over .125-.1875. If they switch to solid wire and 75/25 they'll loose some of that ability. While it does weld cleaner it will not penetrate as well.
 
I did not know that, I do have a 220 machine "BUT" it is a HF machine. It has served me very well for years and it penetrates pretty well. The thickest I've ever attempted to weld was 1/4" with a double pass. Mostly thin gauge stuff though. I usually keep it on its lowest setting.
 
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