What size tanks for an oxy/acet setup?

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Hi, I'm another newbie here with average experience with MIG, flux cored and stick welding.  I have no experience with oxy/acet. I am considering buying an oxy/acet setup, it'll primarily be for cutting 1/4 inch to 1/2 inch steel.  I doubt that I'll do any welding or brazing with it.  In an average month, I'll probably use it 2 or 3 times to cut a few feet of the above mentioned steel.  It'll be light use, cutting steel plate, angle iron, and maybe some pipe.There are 2 LWS in within 5 minutes of my house, so driving to get a tank refilled is not an issue.  What sized tanks should I buy for my setup and for my (in)frequency of use?  I was just guessing that maybe an 80 cf oxygen tank and a 40 cf acetylene tank would be about right, but that's just a guess.  I can find the above tanks online for about $150 and $80 respectively, that's with shipping included.What sized tanks would you suggest that I get?
Reply:I would get the biggest tanks you can.  If you ever want to run a big heating tip you won't need to worry so much about the withdrawal rate on the acetylene.  You'll get a better deal per cubic foot on the refills.  A 250cf oxygen and a (iirc) 140cf acetylene is what I have.If you're having to lug the tanks in and out of buildings, up and down stairs for something like refrigeration work, ignore what I've said.Dynasty200DX w/coolmate1MM210MM VintageESAB miniarc161ltsLincoln AC225Victor O/A, Smith AW1ACutmaster 81IR 2475N7.5FPRage3Jancy USA1019" SBAEAD-200LE
Reply:What AndyA said, bigger tanks are cheaper per cubic foot for refills. And should something bigger than you anticipate come along you'll be able to handle it. I don't have a truck, and the LWS is 25 miles away so I got the biggest that would fit in my Civic.
Reply:The biggest tanks you can handle will always be the best deal, if you don't need to move them all around.  The largest I can handle easily in my car, is a 125cf oxygen, and a 140cf acetylene.  For lots of cutting, your oxygen needs to be -at least- twice the size of your acetylene, but even at that ratio, you'll be filling your oxygen tank about twice as often as your fuel (I don't use my setup for cutting, so a nearly 1:1 ratio works better for me).The MINIMUM size oxygen you should look at would be 80cf, but I suggest at least thinking about a 125cf tank, if you can handle it.The minimum size acetylene tank you should get, would be determined by the size of your cutting tip (40cf size B -might- be ok for you, but if you tell us the torch setup you're looking at, someone here could look up and tell you the appropriate tip size, pressures, draw rates, and minimum acetylene size for what you're looking to cut).
Reply:If you are ONLY cutting did you think of Propane? Our shop in Thompson cuts almost exclusively with Propane and O2. You need the proper setup to do it right but should be cheaper in the long run and you can ALWAYS get propane, if not from the gas station then from under your grill!
Reply:haha, i saw this same post on TractorByNet.com
Reply:Originally Posted by salem747If you are ONLY cutting did you think of Propane? Our shop in Thompson cuts almost exclusively with Propane and O2. You need the proper setup to do it right but should be cheaper in the long run and you can ALWAYS get propane, if not from the gas station then from under your grill!
Reply:I have a feeling the 40 cf acet. may be undersized on the withdrawal rate, especially if you do 1/2" plate. I'd look at a minimum of 75 cf acet. and as others have said the price of gas per cf goes down if you go larger.My 1st set up was a 75 acet / 100cf O2. I definitely found that I needed a bigger O2 bottle. Usually cutting I'd need to get O2 at least twice if not 3 times before I needed acet. Heating, those sizes seem to be about right..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:At first I had a REALLY big (175 cu ft?) O2 tank and a very old (and large...?? cu ft) acet tank.The tanks were way to heavy to lug around and they took up too much floor space. I took them to Airgas here in Houston and ended up with a 125 cu ft O2 and a 75 cu ft acet.  They charged me $35 for a hydro for the old acet tank.  The 125/75 size is right for me as 1) I don't do much torch work, 2) I can get the tanks into the truck by myself and 3) they fit on a standard hand truck modified for a tank cart.The salesman at Airgas said that if I ever wanted larger tanks, just bring in the old bottles and he'd swap for the larger size for a nominal charge. Attached Images
Reply:+1 on the propane.I have the big oxy/acet tanks. However, I quit using acet awhile ago. I keep the tank if I ever need the extra heat or if I decide to try gas welding.But now I use a 100# propane bottle at the shop and BBQ size or 40#'ers in the field. The 100# costs $54.00 to fill and you will lose track of how many "K" size O2 bottles you go thru till it's empty. What else is nice is that Amerigas will give you a 100# for an $80.00 deposit and $54.00 for the fill. No lease or anything. When you're done you get your $80.00 back. But you would be amazed at how long the BBQ size lasts. If you move your tanks around the shop get the small one. I have 125' of hose and my tanks stay put."Where's Stick man????????" - 7A749"SHHHHHH!! I sent him over to snag that MIC-4 while tbone wasn't looking!" - duaneb55"I have bought a few of Tbone's things unlike Stick-Man who helps himself" - TozziWelding"Stick-man"
Reply:Stick-Man: What size O2 bottle would you go with a 20# Prop bottle for a reasonably portable hobbyist setup? Would you still start with a normal setup that you would buy from the LWS for Propane or would you just go with the individual parts needed for propane cutting?
Reply:I'm curious about those cutting/heating with propane. I've always had issues with tanks freezing up in cold weather camping and so on. Do you find this an issue, or is there enough volume to get a decent draw of vapor from the tank. I'm thinking about those who keep their tanks on trucks or outside in temps below freezing, say 25 F and lower..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by salem747Stick-Man: What size O2 bottle would you go with a 20# Prop bottle for a reasonably portable hobbyist setup? Would you still start with a normal setup that you would buy from the LWS for Propane or would you just go with the individual parts needed for propane cutting?
Reply:Originally Posted by DSWI'm curious about those cutting/heating with propane. I've always had issues with tanks freezing up in cold weather camping and so on. Do you find this an issue, or is there enough volume to get a decent draw of vapor from the tank. I'm thinking about those who keep their tanks on trucks or outside in temps below freezing, say 25 F and lower.
Reply:Originally Posted by Stick-manI try not to break anything which needs to be fixed right away when its that coldI have kept a BBQ bottle in the truck on the way to the job and on a wrecking job a couple years ago we used a kerosene torpedo heater on each oxy/prop set.
Reply:Stupid question here:If you're ONLY going to be cutting, and no heating, brazing or welding, you might be better off with a plasma cutter.  After the cost of tanks and a good torch, it's not much more in price, and if you bought one used, it could be less than a new oxy-acetylene setup.The consumable cost is comparable (and probably less, if you're comparing with smaller sized tanks), and it can take up less space.You'd need a larger unit for 1/2" steel, but under 1/4", a plasma is much easier to use (you can make beautiful cuts in thin sheet, whereas, with oxy-fuel, sheet doesn't cut nicely).
Reply:Originally Posted by DSWI'll go out and explain that again to the snow plow. Some how it just doesn't listen and only seems to want to break when it's cold and snowy out. I've got a set of bolts to torch off it this week after snapping a 5/8" x 6"corner protector off in Saturdays storm. It's amazing how steel that thick can just snap.
Reply:You might want to consider abrasive resistant plate for the shoes.  It may cost a bit, but it should save a lot of work.
Reply:Originally Posted by rlitmanYou might want to consider abrasive resistant plate for the shoes.  It may cost a bit, but it should save a lot of work.
Reply:Originally Posted by rlitmanStupid question here:If you're ONLY going to be cutting, and no heating, brazing or welding, you might be better off with a plasma cutter.  After the cost of tanks and a good torch, it's not much more in price, and if you bought one used, it could be less than a new oxy-acetylene setup.The consumable cost is comparable (and probably less, if you're comparing with smaller sized tanks), and it can take up less space.You'd need a larger unit for 1/2" steel, but under 1/4", a plasma is much easier to use (you can make beautiful cuts in thin sheet, whereas, with oxy-fuel, sheet doesn't cut nicely).
Reply:Oh, I'm not denying the merits of an oxy-fuel torch.  I use my torch all the time.  I happen to do all of my cutting with my plasma though (and again, I don't want to downplay the merits of torch cutting, everyone's situation is unique). Given the choice of only having a torch or a plasma, but not both, I'd certainly choose the torch, but the OP did mention just cutting (even if that may be more unrealistic than the OP presumes).
Reply:The boat I am in: I have a PM30 already, it is great for cutting, especially big wide pieces like sheet. But a torch would be good for heating and bending things, and I am sure there would be times it would be better than the plasma.
Reply:Originally Posted by rlitmanStupid question here:If you're ONLY going to be cutting, and no heating, brazing or welding, you might be better off with a plasma cutter.  After the cost of tanks and a good torch, it's not much more in price, and if you bought one used, it could be less than a new oxy-acetylene setup.The consumable cost is comparable (and probably less, if you're comparing with smaller sized tanks), and it can take up less space.You'd need a larger unit for 1/2" steel, but under 1/4", a plasma is much easier to use (you can make beautiful cuts in thin sheet, whereas, with oxy-fuel, sheet doesn't cut nicely).