newbie gas question

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Hey, I am a carpenter by trade and have always wanted a welder.   So I recently picked up a HH 187 and am thinking about picking up some shielding gas.   I am pretty clueless on sizes/prices/leasing/buying etc.   I am thinking leasing is out of the question since I might go 6 months or a year between firing up the welder, so don't want a monthly charge for something I don't use much.  Not sure how long a bottle lasts, should I just buy a small bottle since it might last me 2 years, or just go with a big one and fill it every 10 years, etc.   How long does a typical sized bottle last?  Enough for about 10lbs of wire?  5lbs? 50 lbs?   Any help or tips would be appreciated.   I do not have any "local" shops, but live about 45 minutes out of the twin cities.     Just wondering my best options are?  Thanks,Brew
Reply:At 'typical' small MIG gas flow rates of 20 cfh (cubic feet per hour), a tank will last for tanksize/flowrate = available arc timeSo a 60 ft3 tank would last you for 60/20=3 hours of arc time.An 80 ft3 tank would last you 80/20=4 hours of arc time.The 'typical' small MIG shielding gas for use on steel is C25 (25% CO2 and the other 75% is argon).  Another 'typical' small MIG shielding gas is pure CO2, which is less expensive and the tank lasts longer for its size (because the tank is filled with liquid CO2, which boils to make gas and then the gas is withdrawn through the regulator to weld with).  CO2 may give some more spatter compared to using C25, and typically gives a little deeper penetration (a 'hotter' weld) as well, so it is slightly less suited to the thinner sheet metal than C25 would be.Those gases are for short-circuit transfer on steel.  Other processes and other materials use different gases.  The best laid schemes ... Gang oft agley ...
Reply:sounds like you weld about like I do.  I converted over a small tank that a friend used to fill paintball tanks.  I know when I was looking into tanks in OR I could get a small (think 20#) tank filled for $85 at the gas shop.  If you dont get to town much you may want a big tank, but I would think the smaller one would be fine.
Reply:MoonRise nailed the main points.As far as small tanks 40cf-80cf should do what you most likely will need. Be aware that while small tanks cost less to buy, they generally cost almost the same to fill as a larger tank. Most of that cost is in handling and service work, not the gas. My small 100cf O2 bottle costs just a few dollars less than my 282 cf O2 bottle to fill, yet I get almost 3 times the gas. Check what the refills will cost as well as the cost of the tank. Even though the 80cf tank may be more expensive to buy than the 40cf, the gas fill difference may make the 80 cf a better deal in the long run.You generally also have the option latter to upgrade the tank by trading it in and paying the difference and moving up to a larger size if you find you need to.Hope this helps, good luck.
Reply:Originally Posted by Martygrassounds like you weld about like I do.  I converted over a small tank that a friend used to fill paintball tanks.  I know when I was looking into tanks in OR I could get a small (think 20#) tank filled for $85 at the gas shop.  If you dont get to town much you may want a big tank, but I would think the smaller one would be fine.
Reply:Thanks for the info.  It looks like an 80cf tank would be about right for me.   Now I just have to find a reasonable place to purchase one.   And get it filled reasonably down the line.  thanks again.Brew
Reply:tsbrewers, where are you located? Go to the user CP and post your location so we can all see it. Maybe someone on here can make a recomendation about a good LWS near you that you should try.
Reply:I am really not a big fan of doing that, but I did add it.  Also I did mention in my original post that I am near the twin cities (MN)   Thanks for the help.Brew