poohbear Posted March 19, 2009 Share Posted March 19, 2009 Hi all, hope someone can help out here... I've managed to obtain a bottle of CO2 from work from a friendly bar manager but it has a different connection than more existing regulator. the bottle I've got is a B size BOC bottle of CO2 - which has an external threaded union, and would normally be used in a bar cellar. My regulator (which has been used with an extremely large Argoshield bottle in the past) has a much larger internal threaded union. Can I get an adapter to mate the two together? What sort of sizes am I looking at, I'm guessing they would both be imperial fittings of some description? It would be great if I could use this source of gas as it's obviously a lot cheaper than other suppliers Any help you can offer would be greatly received. dave. Quote Link to comment Share on other sites More sharing options...
poohbear Posted March 19, 2009 Author Share Posted March 19, 2009 Problem solved - looks like this is my next purchase: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...em=150323694854 D. Quote Link to comment Share on other sites More sharing options...
disco tony Posted March 19, 2009 Share Posted March 19, 2009 I think you will find that brewers got wise to this trick quite a few years ago. They now add another gas into the mix which is not inert to steel. I cant remember which gas it is, but you will find lots of porosity in your weld. I am ready to be shot down in flames again for being wrong!! but I dont think I am Quote Link to comment Share on other sites More sharing options...
poohbear Posted March 20, 2009 Author Share Posted March 20, 2009 Bottle says its full of CO2, plain black bottle - ie no Nitrogen mix - so should be OK. The concensus on welding forums I've perused would suggest that this is a common source of shielding gas and as halfrauds bottles last just about long enough to get a couple of tacks on I'm willing to try it. If I do a test seam is there an easy way to check for porosity?! Yet again I find myself at the bottom of a steep learning curve. cheers, Dave. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 20, 2009 Share Posted March 20, 2009 Which welding forums have you been reading then? CO2 sort-of-works as a shielding gas but is not a patch on pukka ArgoShield. Quote Link to comment Share on other sites More sharing options...
poohbear Posted March 20, 2009 Author Share Posted March 20, 2009 stumbled across this when looking for info on bottles and regulators - http://www.mig-welding.co.uk/search.htm?cx...;sa=Search#1057 Besides - the 'hobby' bottle that came with my welder said it was CO2 - and its on the shelves in Halfords next to the Argon. I'm just not prepared to pay a tenner a pop for bottles that last about 40mins I realise that argoshield is preferable, but as the CO2 was free it seems worth giving it a go. My old man used to get 'huge' bottles of coogar (not sure if that is the correct spelling!) for free when he was in a previous job which by the name tells me it had a CO2/Argon mix. Dave. Quote Link to comment Share on other sites More sharing options...
Kim Horsevad Posted March 20, 2009 Share Posted March 20, 2009 Which welding forums have you been reading then? CO2 sort-of-works as a shielding gas but is not a patch on pukka ArgoShield. Depends on what your priorites are with regards to the welded structure. Pure C02 makes more weld spatter, but the weld will be made with greater penetration depth - which normally translate into greater strenght. CO2/Argon mix makes a better looking weld, is somewhat easier to weld with and produce (much) less weld spatter. Much of my welding is done with pure CO2. There is a reason for the different threads on the bottles. Basicly it is an effort to prevent someone unknowlingly connencting the wrong kind of gas (oxygen, acetylene...) to a sensitive or dangerous installation. There are adaptors available to connect the different kinds of threads. Quote Link to comment Share on other sites More sharing options...
TD5 power Posted March 20, 2009 Share Posted March 20, 2009 hi Porosity will usually show up on the surface of the weld as the gasses try and rise through the weld but don't quite get out before it solidifies if you want to check the penetration on a test weld you need to do a macro etch test The other test you can do is a nick break this is only for T fillet and lap joints this is where you cut the center 50mm out of the weld then cut part way through the weld towards the weld root next using a hammer and vice break the remaining part of the weld. i have added a diagram to try and explain it CO2 will give better penetration but the weld will not look as tidy the arc is also slightly less stable when on pure co2 compared to argoshield HTH Matt Quote Link to comment Share on other sites More sharing options...
poohbear Posted March 20, 2009 Author Share Posted March 20, 2009 Many thanks Kim, that makes me feel a little more at ease. Back out to the garage once my adaptor arrives - I just need to keep the bar manager at work on my side! TD5 Power - thanks for the explanation Dave. Quote Link to comment Share on other sites More sharing options...
disco tony Posted March 20, 2009 Share Posted March 20, 2009 Pure co2 is inert to steel enabling its use. It will prevent oxygen contaminating the weld. It will give hotter weld so is recommended for low power units, (clark, machine mart type welders). Argoshield light has 2% co2, argoshield has 5% co2 and argoshield heavy has 10% co2. When mig, (mag), welding, grade A18 wire is used which has ferro-silicon de-oxidising compositon to do what it says! If you got the gas for nowt, give it a go but try it on scrap first. Dont spend too much on adapters in case it doent work! Porosity will look like an aero bar on the weld surface. The patter will be increase with co2 s it does not stabilise the arc as argon does, all bout +ve and -ve charged ions etc. too deep for this time on a Friday, my next pint beckons............. Quote Link to comment Share on other sites More sharing options...
poohbear Posted March 21, 2009 Author Share Posted March 21, 2009 Cheers Tony, have managed to get a patch welded into the rear cross member around the jacking point today. Spatter didn't seem to bad, although I do need to replace the gas shroud on the torch now - biggest problem has been getting satisfactory joins between original thickness of cross member and the new much thicker patch! Bead either blows through thinner stuff or sits on top of the thicker stuff. Wish I'd overlapped it now instead of trying to get it flush. Still its in and I've jacked the truck up on the original point without any disasters. So all in all V.happy Dave. Quote Link to comment Share on other sites More sharing options...
HoggyN Posted March 22, 2009 Share Posted March 22, 2009 My regulator (which has been used with an extremely large Argoshield bottle in the past) has a much larger internal threaded union. I tried CO2 in the past but went back to Argoshield. One of the problems I found was that my Argon type regulator froze up when I used it for CO2. Quote Link to comment Share on other sites More sharing options...
TD5 power Posted March 22, 2009 Share Posted March 22, 2009 hi it depends what pressure the co2 is stored at, welding co2 is usually supplied as a liquid (get more in a cylinder) and is identified by a vertical white line on the cylinder. This shows the cylinder has a siphon tube this type of cylinder has to be used with a vaporizer before the regulator and gauges or as you found out the gauge freezes blocking or destroying itself. The pub gas i think is at a lower pressure and still a gas so shouldn't need a vaporizer but you might get icing at higher draw rates. HTH Matt Quote Link to comment Share on other sites More sharing options...
mike_hammond Posted March 23, 2009 Share Posted March 23, 2009 I'm no professional but I have to say I've had no real issues with CO2 pub gas myself, I always play around with settings on bit's of scrap before setting too on the actual job. I check for penetration and porosity but I normally find running at somewhere between 10-15 PSI at the nozzle I get strong clean welds. Quote Link to comment Share on other sites More sharing options...
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