How much Ar for this?

[Mark @ Everlast]

Looks like more than half of my 80CF bottle is gone. I didn't flip it over yet to do the other side either. I did do about 15 min. of torch practice tho, with it set on 15 l/m the other night when I got it.. had it set at 7 for this truck bed cover.

Jake 15 lpm is like nearly 30 cubic feet per hour. Your bottle would last just over 1 hour at that rate.
You only need 5-7 lpm.

I wouldn't start any project without at least a 125.

Even with it set on 5 an 80 would only last a couple days worth of on and off welding.

 

[Gary Fowler]

Check out this website for gas cylinder pressures. I didnt realize that the smaller bottles were filled to less pressures. We use the 300 c.f.size on construction and they have higher pressures than the home shop size 80 cu ft.
Kaplan Industries Compressed Gas Cylinders

 

[Shield Arc]

Just about all my bottles are 250s, not that I pay a lot of attention to them, but they generally come in between 2200, and 2400-PSI.

 

[dstig1]

Gary - the difference in service pressures on that table is almost nothing. I wouldn't say it is significant.

Mark - it is unrealistic for every hobbyist to have a 125 or bigger cylinder on hand to start any project. You know that

 

[Mark @ Everlast]

Growing up we always used large cylinders. All the people I know, even farmers and hobbyist use large cylinders. Nothing less than a 125. I guess its not as impractical as you think. If you have a truck, no reason not to get a larger cylinder. Cheaper by the volume to fill, and sure cuts down trips to refill. When a hobbyest runs out of gas on the weekend is the first time he should think about getting a bigger tank. In reality a good project will consume a small tank in a day or less. If you are a hobbyest and you are running to get gas more than once or twice a month, you have too small of a tank.

 

[Shield Arc]

I don't have a problem in the world spending money to save money. I own all my bottles, except right now I'm renting a 330 of 90 / 10 to try some spray arc, but it's only $9.70 a month. Soon as I drain it down I'll return it for a bottle of 98 / 2 or maybe not, I don't have a lot of use for spray arc, just wanted to try it out.

 

[jake98]

That's the biggest they sell. I might have sucker stamped on my forehead tho. Nothing else local, and he seems like a good guy.

 

[dstig1]

There are limits to what can be bought vs leased. And if you have a LWS with weekend hours, that helps too. It is a space issue for many people. The little 80 cf units can fit in anywhere, where the 125 is the start of the "typical" cylinders that is tall and needs some room. Biggest I could buy here is 80. I went with a lease on 125 as I thought the 80 was too small and I had a cart made for the bigger ones. Next size up is 330 which goes into overkill mode, pretty seriously. Especially not knowing how much I will use it.

While I think 80's are too small, I can understand why people get them. I stand by my point that it is not feasible for everyone to get bigger tanks, nor does it make sense for everyone.

 

[Mark @ Everlast]

Well depending on where you live, 220/250 is the next in line.

 

[dstig1]

I'm sure, as it does vary. But we're down to 1 LWS here now as the other one (Airgas) moved way far away (way across the metro) for some reason. The one left is the "good one", as far as I am concerned, but they jump from 125 to 330 on Argon/mix. If they had 220/250, I may have gone that way instead. Dunno. Now if I can FIND a 250 cyl on CL or something, then they will still fill it, but they don't have them in stock. I'm looking...