Using Carbon Fiber Argon tanks for portable welding? 88cf is the largest one 12 lbs.

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Using Carbon Fiber Argon tanks for portable welding? 88cf is the largest one and it weighs only 12 lbs. 4500psi about 21" long and 7" diameter.These things have aparently been used by firefighter, SCUBA and paintball enthusiasts. Given that a steal tank of that capacity would weight about 4 x more it certainly has weight advantages. I'd never buy one new they are around $500, but a used one is about half that. the smaller 30 minute tanks go for around $100 on ebay.If i ever get into portable welding work this would   be on my wishlist for sure. They are supposed to be certified eery 5 years and only have 15 year life though!
Reply:Used CF cylinders, rated to 5k psi, for fly-away dive systems.  N2/O2 and mixed gas.  Light, yes.  Expensive, yes.  Unless your LWS will  accept/fill the jugs with gas you're dead in the water.  Most LWSs will not have CF tanks for you to swapout."Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:Plenty of issues you want to think about with one. #1 chances you will ever get one filled with argon to 4500 psi is just about zero. Most cylinders of argon top out at 2200-2400 psi, less if filled by cascade. So right away, your "88" CF cylinder is a 40cf or so. Then there's the valve issues. SCUBA and SCBA cylinders are o-ring sealed cylinders and take a different valve set up than the CGA 580 argon valves. You'd need to build a custom adapter to match up to the valve. I doubt anyone will fill a high pressure cylinder with a custom valve with no certs or history. Then there's the issue with testing and life span. I'll bet any used cylinder you get will be close to it's expiration date. I've seen several guys get really good "deals" on used cylinders like this, only to find out that they only have a year or two on the cylinder at best, and in several cases the cylinders were expired and useless.A steel 40cf cylinder will probably weigh only twice what that alum kevlar wrapped cylinder does. My LWS sells a 60 cf cylinder filled with argon for about $120 or so. The 40's are probably less. The 20 cf ones go for $70 filled. I don't see you gaining anything but hassles by going to a "nonstandard" cylinder. As an aside, the 4500 kevlar wrapped alum Scuba cylinders are worthless, even for diving. Almost no shop except for a few in cave country fill cylinders above 3500psi. Even then once the cylinders cool after fills, you are lucky to be much past 3000-3200psi. The standard alum cylinders are like 6 lb's or more buoyant empty ( 500 psi remaining). The Kevlar wrapped ones are even worse. You might as well try to dive wearing pontoons. The idea of diving is to submerge, not float, and these make no sense what so ever if you really understand the physics of diving. The Kevlar wrapped SCBA cylinders make some sense as firefighters already are loaded down with gear, so every ounce can make a difference. However fire departments can afford to toss cylinders fairly regularly. Really high temps and alum cylinders don't play at all well together. Most alum scuba cylinders are considered junk as soon as they are exposed to any sort of fire. Temps of more than 300 deg will automatically fail a standard alum cylinder from what I recall. A fire department really doesn't care if they have to junk a cylinder if it saves lives. Many alum cylinders like medical O2 cylinders are painted with paints that change colors if exposed to temps above those they are rated for. If the white top of an alum medi bottle changes color, it shows it was exposed to high heat for some reason and is now scrap. I'm betting the kevlar wrapped SCBA cylinders are similar..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:why not just fill them from the larger 160cf tanks I have in my welding shop? No need to have the lws get involved. You're not going to get 4500psi, but you can probably get half that easily.edited to add, thanks for reply DWS, we were typing at same time. I guess the weight savings are not that great afterall.Last edited by AluminumWelder; 05-07-2015 at 07:16 PM.
Reply:Originally Posted by DSWPlenty of issues you want to think about with one. #1 chances you will ever get one filled with argon to 4500 psi is just about zero. Most cylinders of argon top out at 2200-2400 psi, less if filled by cascade. So right away, your "88" CF cylinder is a 40cf or so. Then there's the valve issues. SCUBA and SCBA cylinders are o-ring sealed cylinders and take a different valve set up than the CGA 580 argon valves. You'd need to build a custom adapter to match up to the valve. I doubt anyone will fill a high pressure cylinder with a custom valve with no certs or history. Then there's the issue with testing and life span. I'll bet any used cylinder you get will be close to it's expiration date. I've seen several guys get really good "deals" on used cylinders like this, only to find out that they only have a year or two on the cylinder at best, and in several cases the cylinders were expired and useless.A steel 40cf cylinder will probably weigh only twice what that alum kevlar wrapped cylinder does. My LWS sells a 60 cf cylinder filled with argon for about $120 or so. The 40's are probably less. The 20 cf ones go for $70 filled. I don't see you gaining anything but hassles by going to a "nonstandard" cylinder. As an aside, the 4500 kevlar wrapped alum Scuba cylinders are worthless, even for diving. Almost no shop except for a few in cave country fill cylinders above 3500psi. Even then once the cylinders cool after fills, you are lucky to be much past 3000-3200psi. The standard alum cylinders are like 6 lb's or more buoyant empty ( 500 psi remaining). The Kevlar wrapped ones are even worse. You might as well try to dive wearing pontoons. The idea of diving is to submerge, not float, and these make no sense what so ever if you really understand the physics of diving. The Kevlar wrapped SCBA cylinders make some sense as firefighters already are loaded down with gear, so every ounce can make a difference. However fire departments can afford to toss cylinders fairly regularly. Really high temps and alum cylinders don't play at all well together. Most alum scuba cylinders are considered junk as soon as they are exposed to any sort of fire. Temps of more than 300 deg will automatically fail a standard alum cylinder from what I recall. A fire department really doesn't care if they have to junk a cylinder if it saves lives. Many alum cylinders like medical O2 cylinders are painted with paints that change colors if exposed to temps above those they are rated for. If the white top of an alum medi bottle changes color, it shows it was exposed to high heat for some reason and is now scrap. I'm betting the kevlar wrapped SCBA cylinders are similar.
Reply:I'm mostly familiar with the codes and stuff for the scuba cylinders as I worked for the dive shop. We did deal some with a few fire companies and individual volunteers with there own SCBA's on occasion. Mostly guys who also dived, but occasionally we did some work on their HP compressors as the sister company did that sort of work. I know a lot of the companies around here were changing over from the older steels to other rigs at the time when I left. I've got 2 full SCBA rigs with steels in the basement compliments of someone who brought them in to me from work when they dumped them. I think both were new and never used that they had as spares..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 AluminumWelderwhy not just fill them from the larger 160cf tanks I have in my welding shop? No need to have the lws get involved. You're not going to get 4500psi, but you can probably get half that easily.
Reply:Originally Posted by DSWI'm mostly familiar with the codes and stuff for the scuba cylinders as I worked for the dive shop. We did deal some with a few fire companies and individual volunteers with there own SCBA's on occasion. Mostly guys who also dived, but occasionally we did some work on their HP compressors as the sister company did that sort of work. I know a lot of the companies around here were changing over from the older steels to other rigs at the time when I left. I've got 2 full SCBA rigs with steels in the basement compliments of someone who brought them in to me from work when they dumped them. I think both were new and never used that they had as spares.
Reply:are there any fiberglass welding tanks?
Reply:Originally Posted by rustyshakelfordBefore I got married I heavily invested my time and money in tech diving. Loved the sport but when I began caves and looking at going the rebreather route is when I began paying closer attention to the fatalities. Being newly married and planning on kids I stopped tech diving. Rec was boring at that point and I haven't dove in probably 4 years. I take enough risk at work and didn't want to chance a faulty O2 sensor to take me out in a cave or some other unforeseen incident. You've got me curious about your O2 burns. What happened? I'm th first to admit I've been not as cautious as I should be because I've never heard anyone actually getting hurt. When I started taking a nitrox course they were adamant about getting the cylinder O2 cleaned for fear of a fire. Never understood the dangers but followed their rules. Guess Ive never looked at oxygen as something that is so dangerousBrett
Reply:Originally Posted by AluminumWelderare there any fiberglass welding tanks?
Reply:As others have noted, oxygen tanks for medical use are often aluminum. The link below discusses aluminum tanks for compressed gases.http://alspecialtygases.com/Prd_high..._aluminum.aspxWith all the problems that people have pointed out, you are probably better off looking for smaller cylinders, rather than trying to go for the lightest possible cylinder of a given size.   If your concern is portability, then weight is the key.    But of course gas is always cheaper in larger containers than small.My LWS offers relatively small tanks for inert gas, I think that they are old medical oxygen cylinders.  I have one for tri-mix gas, since I use it infrequently.  It is a tall skinny tank, and kind of odd looking.  I keep it in a rack on the wall for storage, and then lay it down on the rare occasions that I need to use it.  (Obviously fuel gas tanks need to be used upright).  One odd fill setup is used in the medical field.  It involves a very large tank with liquid Oxygen.   You fill the portable tank with liquid oxygen from the big tank.   Since there is liquid involved, the pressure is a function of the temperature, and so is constant, whether the tank is full, half-empty, or almost empty.  (I am simplifying the story a bit).   When you see an old person walking around with an oxygen tank in a pack on their back, it is full of liquid oxygen.      One concern is that if you withdraw gas at a high rate the pressure in the tank can drop, as the tank cools.  Because the oxygen is cold, the tank pressure is not that high, so the tank does not need to be as heavy.  They have a pressure relief valve, so they can bleed oxygen if needed.Sculptures in copper and other metalshttp://www.fergusonsculpture.comSyncrowave 200 Millermatic 211Readywelder spoolgunHypertherm 600 plasma cutterThermal Arc GMS300 Victor OA torchHomemade Blacksmith propane forge
Reply:I've never seen the small liquid O2 systems. All the small medi o2 cylinders I've seen were all gas..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