Converting to Shielding Gas...

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Hey there,OK, I'm thinking I might at some point want to convert my wire feed welder to use shielding gas. It is a Deca welder (see sig) and is capable of being upgraded to use gas. I just have some basic questions (sorry for my ignorance)...What would I all need? Obviously a cylinder of gas, but what about regulators, hoses, etc.? Is it usually a simple hook-up? I can't remember exactly, but I believe the welder has a small clear hose coming out the back (or somewhere). Is this where the hook up is made?Do I need a special tip or trigger assembly for the welder (I think not, but...)? I also assume the gas is operated by the same trigger as the wire and that it only flows when the wire is being fed?What gas works best? Considering I am a home handyman welder, I'd be looking for a "general purpose" gas, if such a thing exists.How long does a small cylinder of gas last? I have a cutting torch with a medium size o2 tank and it has lasted me a number of years - - but I obviously don't use it very often. I expect to use all of this stuff more once I have my shop built next year, but even so, I am not a production shop.So, any thoughts or heads-up here from the experts? Thanks in advance for your advice.Weekend MigBackyard MechanicWelder: DECASTAR 150E, Wire Feed w/ Gas Potential (not currently using gas)
Reply:As for the questions about hooking up gas...The gun needs to be a MIG gun, not a fluxcore-only one.  They look different.  Fluxcore wire will run through either type of gun, but the mig gun has a liner that carries the gas.  You can use a regulator, but a flowmeter+regulator is much better...look up flow meter on ebay to get an idea of the difference.  If you have a hookup already in the machine, you probably have a gas solenoid...that is the thing that turns the gas on and off automatically when you pull the trigger.  [If you dont have that, you will need one.  Your manual should show how the solenoid is wired in (generally two wires).]  Once you have that stuff squared away, you just connect the flowmeter-regulator to the tank, hook up the hoses and MIG weld.  There are lots of mixes used.  I tend to use pure argon (mostly) or 25/75 co2/argon (sometimes)...but it depends on the metals you want to weld.  Pure is for aluminum mainly, but can be easily used on steels.  Co2 mixes are mainly for mild steels.  To me, small tanks cost more than they are worth and dont last long enough.  Get as big a tank as you can afford and move by yourself...that is if you intend to leave the welder in one place most of the time.  Smaller tanks are useful if you REALLY need mobility.  Note, I mig occasionally, but that's not my first choice...so, other more frequent miggers may have different and more informed opinions on your questions...Mine is just one.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Thanks Man, I appreciate the feed-back.Yes I believe my gun is set up or gas. I will have to take a look at my machine and the manual tonight (I am at work right now) to confirm the parts that already exist.This is by no means a panic for me now, but it's always good to have the information in advance of really "needing" it.Thanks again.Weekend MigBackyard MechanicWelder: DECASTAR 150E, Wire Feed w/ Gas Potential (not currently using gas)
Reply:Howdy Howdy!  It sounds like your machine is prepped allready.  You will nead a regulator, (a flowmeter is more accurate yes, but unnecesary for this level of machine and mig in general). You can use several gases as stated.  100% CO-2 is great for a deeper penetration at a set heat then others.  75/25 also known as C-25, is a great all around gas for little mig machines.  It can also be run through any over the counter inert mig regulators, and will not freeze up your regulator like 100% CO-2 CAN do for some not rated for 100%.  The CO-2 is a great tranfer-er of energy, good for welding with small welder, bad for regulators not designed for it.  The argon in the C-25 mix is great for dirtier metals, if some rust (not alot) exists on work.  Also better for mill scale which is what I mostly deal with, and use.  100% argon is almost solely for alluminum and the highly highly reactive metals, or for tig welding and other processes.  I also recomend the biggest tank you can man-handle without hurting yourself.  I have 3 myself, 1 small-ish 80 CuFt (my 1st tank) and 2 seperate 250 CuFt tanks.  As a side note, the gas only costs about 15$ more for 4 times as much gas.  The 80 cu ft tank is fairly easy to move, and they are all owner tanks in that size (no way to accidentaly get a rental tank as an exchange). Then you factor in driving to supply house blah blah... Bigger tanks are alot cheeper in the end, if you use the gas.  You can always trade in your 80CuFt for credit on a larger tank.  So, in  conclusion, I would suggest a small mig regulator = 40$ or so, an 80cuft cylinder = 125-165$, and a C-25 fill =20$.
Reply:Thank-you very much!!!  I will definitely keep this information on file for when I want to do this. Like I said, It may not be until I set up my garage/shop later this year, but I'm glad to get this information, so I can keep my eyes open for good prices on stuff in the mean time. The store I deal with for this type of stuff is constantly running sale flyers, so the chances of the regulator (or flowmeter) going on sale in the next few months is probably pretty good.Keep the tips coming...Thanks again.Weekend MigBackyard MechanicWelder: DECASTAR 150E, Wire Feed w/ Gas Potential (not currently using gas)
Reply:I converted my Lincoln Weld-Pak 155 to gas using a kit from Lincoln ($75).    I had to add a jumper wire on the controller board, reverse the polarity of the electrode, install a gas solenoid and pipe it to the torch hose.    I also had to change the cable liner  and electrode to better handle the thinner wire.   The regulator that came with the kit is crap.  I plan to swap it for a flow meter.   I found a 40CF gas cylinder at a flea market for $30 and lucky me, it passed hydrotest.   You should check Ebay for gas cylinders.    Except for the regulator, I very happy with the switch from fluxcore to MIG.There are no small projects
Reply:Howdy!  I believe those kit regulators are standard cheepie harris inert regulators.  the type I would recomend not using for 100% CO-2.  They should be fine for the mixed gases, even if they are inexpensive.  A high quality flowmeter/regulator is really only needed for tig work, or other more precision applications. like Titanium or alluminum and such.
Reply:Originally Posted by Sparkeee24A high quality flowmeter/regulator is really only needed for tig work, or other more precision applications. like Titanium or alluminum and such.
Reply:Thanks again for all the suggestions here guys. I spoke to a local gas supplier - the one who supplies my O2 for my oxy/propane torch. It sounds as if a C-size (approx 60 cu.ft.) cylinder with the first fill is approx. $250 (canadian) plus about $50 for a regulator and we're talking about $300....Looks like I may be waiting a bit to do this. The welder works fine for my purposes without gas, but I will likely want to try doing this at some point in the future. I'll have to get the $15,000 garage/shop finished first. I'll definitely be saving this info for the future - - thanks again.Weekend MigBackyard MechanicWelder: DECASTAR 150E, Wire Feed w/ Gas Potential (not currently using gas)
Reply:That sounds high to me..Maybe some of the other guys will respond.regards, Farris
Reply:also as imagineer breafly touched on you will need to reverse the output polarity on your machine when you go with gasWire and Gas = electrode - work +Flux Core Wire = electrode + work -MC
Reply:Hi Weekend Mig!I've got similar ambitions: to go from flux-core to gas.  Yes, I love the portability look of the 20 cu ft tanks but talking to the local gas suppliers limited my options - unless I want to get into refilling a 20 cu ft tank from a larger tank at home... probably frowned upon.The gas supplies told me that tanks of less than 80 cu ft are owner tanks - you buy em and own them.  They recommended the 40 - 55 cu ft tank; it seems there are new and older tanks of somewhat different capacity that are exchanged as if the tanks were the same - go figure!  Anyway, when the tank is empty, you exchange it for a full one - that means one trip to the gas supplier.  If you choose to go with a 20 cu ft tank, there may be problems.  If the supplier can/will refill it, you have to drop it off and then return to pick it up = two trips.  Here in Ottawa, neither of the two gas suppliers wants to fill tanks; their tanks come pre-filled from Montreal, the local suppliers just sell em as they come.Prices in Ottawa (Jan 2006) for a 40 - 55 cu ft tank:Supplier 1 = Air LiquideCylinder price = $185 (that $US 157 for you southern folk)Ar3 fill = $40 ($US 34), Ar-CO2 fill = $46 ($US 39)So, 1st time = tank + gas = ~$231 ($US 196)Supplier 2 = BOCCylinder price = $280 ($US 238) with the ist time fill included*Ar3 fill = $55 ($US 47), Ar-CO2 fill = $62 ($US 53)*Thus, cylinder price alone = $280 - $62 = $218 ($US 185)If you compare those cylinder prices to prices on US web sites, you will quicly discover a major price disparity between Canada and the USA - that in fairness probably reflects the web versus local suppliers price disparity too.From the web store Cyberweld:20 cu ft cylinder = $US 78   (that's $CDN 92 for us Northern folk)40 cu ft cylinder = $US 115 ($CDN 136) - compare that to $CDN 185 local80 cu ft cylinder = $US 170 ($CDN 200)From the web store weldingsuppliesfromioc:20 cu ft cylinder = $US 62   (that's $CDN 73 for us Canuks)So, that's what I learned.  I hope it helps.Rick V
Reply:Howdy Howdy!  I STILL wouldn't go with anything smaller then an 80 Cu Ft tank!  at about 20 cfh out of the regulator, you get 4 hours of actuall arc time.  That may seem like alot, untill you really get into it   It's still twice as long as a 40 CuFt will last! at how much more $$$? Between 40-55$ a fill, for a 40 CuFt fill in Ottowa...  Price out an 80 CuFt fill, I bet it's only like 15$ more, if that.  Of course they want you coming back twice as often, because they make they're money off the turn around of the cylinders, not when you buy alot of gas and the tank is at home.  They want you to get small cylinders, cause they make more $$$ with them. The more your in their store, the more likely it is that you'll spend money there.  With the prices of fuel, it's worth it just to save the trips for fills!  Brian Lee  Sparkeee27
Reply:I just filled my 80cf. of argon for 41.00 and change, this morning. I thought it was kinda high, but a frien told me that prices were going up again, so I guess I'll take it with a grain of salt.
Reply:Sparkeee made some valid points.  I looked through this site for past discussions on how long a bottle of gas lasts and value comparisons of flux-core wire versus metal wire with gas and found the following.===================================I use a 135 lincoln on a 40 pound CO2 bottle for handrails and sheet metal because we can move it around half way decently, and can always find a 110V outlet.  Usually it takes about 3 bottles (each 40 cuft) to run thru a 10 pound spool or atleast the way my machine runs it does.The price of the bottle for GMAW is steep on that inital investment, but fills are only 35$ for my 150cf C25. Thats good for about 10 pounds of wire. Its pretty much a wash in the long term when you consider solid wire+gas vs fluxcore.For reference, you will need to run a flow of 20 to 30 scfh depending on the ambient air movement and the work. So, a 40cf bottle will last, on average, about 1.5 hours of actual trigger time.===================================Given these gas numbers (20 - 30 cubic ft per hour), a super portable 20 cf cylinder is not going to last too long! (Just as Sparkeee says.)20 cf   = ~3/4 - 1 hour40 cf   = ~1.5 - 2 hours60 cf   = ~2.2 - 4 hours80 cf   = ~3  -  4 hours160 cf = ~6  -  8 hours250 cf = ~9 -  12 hoursHopefully tomorrow I will remember to phone the local gas dealers for cylinderpurchase, rental and fill up prices for the you own cylinder and the larger rental cylinders.  Then I can provide the $ figures.Rick V
Reply:OK, here are the cylinder and gas prices in Ottawa, Canada on Jan 30, 2006.Note: year = yrSupplier 1 = Air Liquide,CylinderSize.......To Buy..............To Rent...................Fill Ar.................Ar-Co55 cf......$200 ($US172)...Not available.............$40  ($US35)......$ 40 ($US35)80 cf......not available......$55/yr ($US48/yr)......$45  ($US39)......$ 55 ($US48)150 cf....not availble........$70/yr ($US60/yr)......$60  ($US52)......$ 70 ($US60)300 cf....not available......$80/yr ($US69/yr)......$130 ($US112)....$140 ($US121)Supplier 2 = BOCCylinderSize........To Buy..............To Rent..................Fill Ar.................Ar-Co55 cf......$222 ($US191)....Not available...........$57 ($US49)........$64 ($US55).............$282 with gas127 cf.....not availble........$95/yr ($US82/yr)....$57  ($US49)......$ 67 ($US58)163? cf....not available......$95/yr ($US82/yr)....$125 ($US108)....$150 ($US130)Beware of that last '163' entry.  The BOC dealer was confused on the 163 cf cylinder; at first he said it was 163 cubic meters!  That would be huge 1722 cubic feet.  The fill prices look more like the Air Liquide 300 cf cyclinder.So what does this show?  Sparkee predicted, "I bet it's only like 15$ more".Yes, if you rent a tank, for about $15 more per year and $15 more per fill, you can even move from 80 cf to 150 cf.  That's a big saving.On the smaller side, one has to weigh the economics of paying $200 for a 55 cf cylinder, then filling it at $40/time compared to renting an 80 cf cylinder for $55/year, then filling it at ~$50/time.e.g. Hey, if you're just starting and only got $100 in your pocket, the rental deal looks good. Anyway, there it is...Rick VLast edited by Rick V; 01-30-2006 at 03:11 PM.
Reply:Ooops...According to AirLiquide web site, there is such a monster as the 162 cubic meter cylinder that the BOC supplier thought was an error.  It holds a whopping 5,842 cu ft!  (I got my previous math wrong: squared when I should have cubed.)  Not only that, there is an even bigger one = 12,730 cf!From the AirLiquide web site:Product Code.........UOM.......Size Volume...........Pressure                                         ft3 m3psi kpa  GAS-ARG22...........22.........121.5......3.44......2,  217.....14,960   GAS-ARG9COP.........9.........49.8.......1.4........2,  217.....14,960   GAS-ARG50............50........329.49.....9.33.....2,6  40......17,820   GAS-ARG50XPR.......50 XPR..543.1......15.1......4,500......30,380   GAS-ARG160LC.......160 L....4,291.6....119       GAS-ARG180LC.......180 L....4,796.5....133       GAS-ARG240LC.......240 L....5,842.3....162GAS-ARG450LC.......450 L....12,730.5...353Rick V
Reply:Things are WAY different in canada with gas pricing and tank rentals Vs. purchase.  You should come down here and get a few tanks  Brian Lee  Sparkeee27  Ya'll are getting screwed!  Then again, I pay 1.25$ / lb for scrap steel (clean).  I here most prices down around half that even down to 15 cents a pound for good clean scrap and short cuts.  So with Steel prices, I'M getting screwed!  Oh well, what can you do.  Brian Lee  Sparkeee27
Reply:Ok new thought.  Cyberweld has 80 CU ft cylinders for 170$ US. Free shipping in the US.  They WILL ship to canada as well, at what rate, I'm not sure.  Don't know that rate.  Am trying to put something together for you canuckleheads.   Brian Lee  Sparkeee27
Reply:OK this bites!  I'm not finding anything really affordable for ya'll.  What I know is what I pay.  For a 250 CuFt Cylinder, also called a size "K", weighs darn near too much to lift onto my porch bye myself...and up the stairs into my mobile home (where it then bowed down the floor untill I found a strong supporting spot directly ontop of the steel frame rails with concrete block underneath)... anyway. WITH a full fill of Argon, it cost 265$.  For the other tank ( as I bought 2) it cost 255$ with a full fill of C-25.  They're a good 4 1/2 ft tall and a good 9-10" across.  So, that's what we pay down here.  And I think I am getting a good deal on tanks cause I'm right off of Seattle, where the things get shipped in from China or wherever.  Good luck folks!  Brian Lee  Sparkeee27
Reply:Sparkeee - thanks for trying to look after us Canuks!When I got those prices on the rental-size tanks (anything greater than 55 cf), I overlooked to ask what the suppliers charge for delivery to your door.  That's a cost factor too.  For rental cylinders, I would have to open an account at the supplier.  That's no problem - if I can just phone them and their truck comes around with a cylinder... that saves me the drive and hazzle of stuffing a cylinder into my vehicle.Question for you Sparkeee:In my table, the closest size to your 250 cf cylinder was a 300 cf cylinder with a rental of $US69/year and fill prices of $US112 for Ar or $US121 for AR-CO2.  Now, you say your K-size 250 cf cylinder costs you ~$260 with a fill.  Comparing prices, I assume that means you can buy a full cylinder outright (you own the cylinder) for that $250?  If so, what's it cost to fill it?Funny thing: I've noticed in several postings that pure Argon appears to be more expensive in the USA than an AR-CO2 mix like C-25.  In Canada, the reverse is true - pure Argon is cheaper!  It makes you wonder what is going on???Enjoyed the chat...
Reply:Howdy Howdy! RThe prices I gave you were purchase price outright, with a complete fill.  I won't pay more then 200$ US for a K size tank, 250 CuFt.  Now, see because their are so many diferent gas mixes, with different pressures, and specific gravities blah blah... that a 250 CuFt tank, is only a 250 CuFt tank with a specific gas. That is one reason why they call it a size K tank.  http://www.bocgases.ca/newsite_eng/news/news25.html Maybee this will give some info for ya.  K size is what I have, and the prices affore mentioned, was for Tank, AND GAS.  Yes, that is odd, that the prices for gases are reversed from area to area.  It really depends on location, but man, this is a huge gap in pricing.  Brian Lee  Sparkeee27
Reply:the polarity as posted was backwards....   solid wire gas and gas flux is electrode positive.  Selfshielded flux is electrode negative.  Verify this with your wire, will say on the box.IF it Catches...Let it Burn
Reply:I believe it's probably wise just to check the box that the wire came with.  I've seen self-shielded and gas-shielded wire of various types that used either polarity.  Though it would suffice to say that self-shielded is usually DCEN.-Heath
Reply:If it dont say it on the box..highly doubtful..but if it dont, search the wire type and brand on the google or whatever.  It should give you specs with the polarityIF it Catches...Let it BurnNear the beginning of this thread there are questions about folwmeters.  I am curious, say that I wanted a high end flowmeter.  What would you suggest?  I am running a Lincoln Power Mig 255C.  Yes I know I don't need it, but was just wondering.  Hey, thats just me.  Also I would like to thank everyone in here for all the great info, it has been very helpfull and I sincerly appreciate all of you taking the time to help us less knowledgeable ones.  I tip my hat to you.  Thanks!!!
Reply:I like C02 for my general mild steel work around the shop. The penetration is excellent. There is a little more spatter than Ar/C02 and the weld is not quite as pretty but the prices can't be beat on C02. There is anti-spatter spray available that helps a lot. A 20 # liquid C02 cylinder is equivalent to about 160 cu. ft of gas in a larger tank. Each pound of C02 is about 8 cu. ft @.1234 # of C02 per cu. ft. of gas equivalent.They are about $25-30 exchange in Sacramento and do seem to last a long time. They are shorter but larger in diameter so I had to make an adapter for my Lincoln Cart. Argon is about $60-70 per cylinder here and Ar/C02 is a little more.I like .023 wire with about 20 cu.ft on the regulator. I don't use the little regulator that  came with the Lincoln SP175 plus. I got a used Smiths flowmeter regulator from a friend and it works very well. Good luck.Last edited by gnm109; 05-16-2006 at 09:51 PM.