Gasless Wire Welding Is A - Welding Supplies & Welding .
PHOTOGRAPHS: GEOFF OSBORNEBy Greg HolsterGasless wire MIG welding.Gaslesswireweldingis abreezeNo dramas with windor shielding gas withgasless wireGasless welding using a flux-coredwire is a MIG welding processthat relies on a continuous, tubularwire feed. Gasless wire welding wasoriginally designed as a replacementfor stick welding, mostly for use out-Grinding. for clean earth-to-metal contact point.side where protecting gases could be blown away bythe wind and higher productivity was necessary.The filler metal for theweld is basically an arcwelding electrode turnedinside-out. This mild steeltube or sheath becomesthe main filler metal to thearc.Wire sizes can range from 0.8 mm upto 3.2 mm and more. Stainless steelgasless wire is available in larger-sizedwires but this is a more specialisedconsumable made by Stoody out ofthe USA. Hard-facing consumablesare also available, normally from 1.6mm upwards. To my knowledge, aluminum is not available at all.FluxFlux components are rolled into thewire like a very long “roll-your-own.”This flux is essential in shielding thearc from the surrounding atmosphere.In chemical makeup, the gasless fluxcored wire has more carbon, manganese and silicon than a normal MIGwire. The compounds that make upthe flux in the core of the wire are approximately 15-20 percent of the totalweight of the wire.The way this flux functions:the shed63
Deoxidizers act as a scavenger toproduce a pure, solid weld; Slag forms to cover the surface ofthe weld pool and protect it from theatmosphere until it has solidified; Arc stabilisers produce a smootherarc and the good wires have less spatter; Alloying elements are an added helpwith strength and advanced weldmetal properties; The flux includes vapour-formingcompounds which provide the gaseous shield needed to protect againstoxidisation.The gasless, flux-cored process doesnot have as fast a deposition rate ashard wire or flux-cored wire usinga shielding gas. As it is an electrodeWeld on galvanised has slag.Good practice is to remove coating.and slag cleaned off.turned inside-out, the deposition ratesand welding speed are similar to thatof a standard arc rod.BenefitsSome of the benefits of gasless wirewelding: Where breeze or wind is a problem,gasless wire is the solution. As withan arc rod, there are no dramas withshielding gas when the wind blows; No need to rent or drag around a gascylinder; Tubular construction makes thewires very stiff and they have excellent longitudinal strength. Feedability through the rollers and the MIGtorch-liner is excellent.PolarityFor gasless welding, polarity changes.Your MIG should be set up with apositive earth and negative electrode.64the shedVariables on cover of the machine makeadjusting simple.Control knobs for wire-feed speed andvoltage.
Vertical-up weld (1).Vertical-up weld (2).Finished vertical-up weld.This is unlike stick and MIG using ashielding gas, where negative earth isthe norm. This puts more power intomelting the wire.Try welding with the wrong polarityto give you an idea of the difference.On some machines it may work justas well, though most welders will finda big difference. Wrong polarity is acommon problem that the inexperienced welder can encounter. Manyusers I have spoken to who havetried and not liked the gasless processhave not been aware of the polaritychange; they have been welding withthe wrong polarity.Sheet metal.Most MIG machines will go down lowenough to weld very thin, sheet steel.But some don’t. If your machine islike this, try a longer stick-out. Thisincreases the resistance-heating of thewire just before it melts, preheats thewire and lowers the heat available formelting the parent metal.The result is that the weld bead hasshallow penetration and a small bead.This longer stick-out makes weldinglight-gauge material very easy, andperfect for bridging gaps, filling holesand welding projects that have poorfit-ups. This is common when we arerushing.Seismic, single-passWires used for structural applicationsshould have seismic certifications.Check that what you are using is OKto use when welding anything structural that may need seismic specifications. Some wire specs are limited tosingle-pass applications. Again, checkthe wire’s limitations.Prepare the workWhen clamping the earth cable to thejob, make sure there is a clean earthto-metal contact point. As with anywelding process, a bad connection cancause voltage losses. The result of thiscan be convex or lumpy beads whichStick-out at 25 mm.the shed65
come typically with low voltage. Undersized or badly worn earth cablesare also commonplace in backyardapplications. It takes five minutes tocut and redo the earth clamp.Most gasless wires are renowned forbeing able to weld over galvanised,painted and rusty surfaces, primarilybecause of the extra goodies addedto the flux. Gasless flux-cored wireis often used in industry because ofits “galv-friendly” characteristics. Butnormal good practice in any weldingprep calls for removing as much ofthe coating, dirt, rust etc as possible,especially when you are welding outof position.Optimum wire-feedA bad habit for a lot of part-time welders is screwing the wire-feed tensionright down. On a tubular wire, thisis a bad start. It can deform the wireand cause it to pig-tail or curl. Not tomention the filings which will collect in the wire-drive unit. Sheddiesand industry (panel-beaters note) willfind dirt and dust gathering, not tomention over-spray, if they leave thewelding machine cover open whilesanding, welding or grinding.Set the tension just enough to startfeeding and then give it another halfa-turn for good luck. If more is needed, check that the liner is letting thewire run smoothly.When was the last time the liner waschanged? This is maintenance youneed to keep on top of. Clogged orblocked liners are the root of so manyfeeding problems and often the lastthing to be thought of.When replacing the wire and beforeputting the new coil into the driverolls, round the end of the wire andensure it is burr-free.Replace the contact tip when it becomes worn or when you’ve had afew too many burn-backs. Rememberthis is the contact point for your arc.Best settingAdjusting the wire-feed speed andvoltage should be simple enough ifthe manufacturer has put the variables on, or in, the cover of the machine.If not, try this. To start, try a settingin the centre of the wire-speed knob66the shedLeaving cover open invites dust and dirtto contaminate wire-feed.Pig-tail or curled wire can result fromscrewing down wire-feed tension.range and the same on the voltageswitch. If the wire feels like it is burning off before it reaches the plate, goup one adjustment on the wire-speedknob. Keep going until the wire juststarts stubbing or cracking in sound,then wind the knob back. If the wireis stubbing, either go up one adjustment on the voltage knob or onedown on the wire-speed knob.If you find the weld is too concaveor has porosity, the voltage is stilltoo high. A weld that is too convexor rounded means too much wire iscoming out for the voltage setting.The more you play with your welder,the better you will get to know whatit will do. But buy a few extra tips,you may need them.Travel speedAs in other welding processes, theideal travel speed is one that keepsthe arc / burning wire at the frontedge of the weld pool and is producing the desired weld size. The bestway to maintain a constant and uniform travel speed is through practice.Maintaining a constant distance between the wire and the molten poolwill also help. One supports the other.When starting out, it can be hard togauge whether your travel speed istoo fast or too slow. If it looks goodand feels strong, then you are probably on the right track. But don’t walkunder anything you’ve welded thatyou are not sure of.Stick-outStick-out is the distance betweenthe contact tip and the parent metal.Around 25 mm-35 mm is about themean distance for wires from 0.8mm-1.2 mm. It is important to keepthis constant as the amps and voltswill fluctuate if you wander in andout. I like to use 25 mm stick-out.But you can use the stick-out distanceto your advantage. If you use a longerstickout (say 40 mm), the wire preheats slightly because of the electricalresistance. In turn, the volts will dropslightly, reducing penetration and thechance of burn-through. This technique is also ideal for bridging gaps.Use upward torch angle for verticaldown weld.Backhand techniqueAngle the MIG torch back away from
the weld pool in the direction you aretravelling. This is the same techniqueas with an electrode in stick welding.If you find that the slag starts to runahead of the arc, this means drag angle needs to be increased. Too great abackhand angle and the arc could become unstable. Porosity and an uglyweld will tell you that you’ve gonetoo far.Down-hand fillet weldsTo make down-hand and small fillet welds, point the wire at the toe ofthe joint. Try to keep the wire angleto the joint around the 45 mark. Toachieve an even better bead shape,position the wire onto the bottomplate close to the corner of the joint.An angle of 45 between the wire andthe base plate will ensure the moltenweld pool will wash up onto the vertical plate.Vertical-up weldsWhen welding out of position, theToo high voltage is a common cause of porosity.secret is to keep your movementssteady. Moving fast or whipping thearc will give you lumpy welds becausethe weld pool has got hot and coldtoo quickly. Generally, keep the wirenearly perpendicular to the joint forvertical-up welds.The easiest technique is a short side-to-side motion, counting 2-3 secondson each side. Do not be in a rush toget to the other side. Practise on a 4-5mm plate. Do not worry about thecentre—it will take care of itself. Youshould be aiming for a weld 8-10 mmwide. Good penetration can also beachieved with the right settings and.co.nzthe shed67
good technique. Practice will tell youhow quickly to move up the plate.Vertical-down weldsTo make smaller vertical welds, a vertical down technique is usually used.With practice, excellent high-speedvertical welds can be achieved.For sheetmetal work, low-penetration single-pass welds can be achievedby positioning the job on a downhillangle or straight up and down.You use an upward torch angle (keepyour hand lower than the tip) of between 15 - 20 moving down at aspeed that keeps the molten pool fromrunning over or onto the wire. Youwill find you will be moving downquite fast. The force of the arc willhelp hold the weld pool in the joint.PorosityPorosity in gasless wire is a commonfault but easy to avoid.To eliminate porosity: Clean the parent metal of moisture,oil, paint and rust; Decrease your voltage. The arc mayfeel hot and smooth but too high avoltage is the most common fault; Increase stick-out. Short stick-outraises the arc voltage; Increase wire-feed speed; Decrease drag/travel angle. Toogreat an angle can also cause extraspatter.Operating variablesThere are four major operating variables in MIG welding: arc voltage,wire-feed speed, torch travel speedand stick-out. If you change one, theother three will probably also need tobe adjusted. As stated earlier, too-highvoltage compared to your wire speedcan cause porosity and pin holes. Toolong stick-out will give you stubbingand heavy spatterTravel speed isn’t too hard to work outas the finished product will let youknow if you need to fix this. Don’t beafraid to move quickly on panels andlight sheet.FumesOf course, you need to be aware offumes from gasless wire welding.With fumes, all welding should betreated with the same precautions.68the shedWear protection of the correct typefor the job you are doing. Materialsafety data sheets on most consumables are available on-line or ask thecompany supplying the wire if youhave any doubts.Beware of fumes. This welding isoutside in open air.Weld on galvanised. and weld on galvanised cleaned.CostThe cost of gasless-wire welding willdepend on where you buy your wire,the size of roll and the diameter ofwire you require. On its own, it isgenerally more expensive than plaincopper-coated hard MIG wire but youdon’t need to pay for shielding gasand cylinder rental.Gasless flux-cored MIG is a great toolto have in the shed. Mine is set uppermanently. I switch it on and startwelding. And at the end of the day,that’s the name of the game.
asless welding using a flux-cored wire is a MIG welding process that relies on a continuous, tubular wire feed. Gasless wire welding was originally designed as a replacement for stick welding, mostly for use out-side where protecting gas-es could be blown away by the wind and hig
Hot wire Welding speed comparison in cm/min.: PF position: manual TIG welding with 3.2 mm fi ller wire; tigSpeed cold wire and tigSpeed hot wire with 1.0 mm fi ller wire 20 15 10 5 0 Welding speed [cm/min.] tigSpeed cold wire TIG manual tigSpeed hot wire With TIG cold/hot wire welding, the we
black black white white white white red green blue black Wire 3 Wire 3 Wire 4 Wire 4 Wire 5 Wire 6 Wire 8 Wire 7 Wire 2 e 2 Wire-number Wire color Wire-number e color For multicolor configurations For all other configurations * internal pull-up resistor to vcc 3.3 V Dimension 15.15
6.3 Mechanised/automatic welding 114 6.4 TIG spot and plug welding 115 7 MIG welding 116 7.1 Introduction 116 7.2 Process principles 116 7.3 Welding consumables 130 7.4 Welding procedures and techniques 135 7.5 Mechanised and robotic welding 141 7.6 Mechanised electro-gas welding 143 7.7 MIG spot welding 144 8 Other welding processes 147 8.1 .
Wire Size Wire Size 20.75mm 1.50mm2 E1010RD EN2502 (10mm) (12mm) Wire Size Wire Size 21.00mm2 2.50mm E1510BK EN4012 (10mm) (12mm) Wire Size 21.50mm 4.00mm2 E2512GY EN6012 (12mm) (12mm) Wire Size Wire Size 2.50mm2 26.00mm E4012OR EN10012 (12mm) (12mm) Wire Size Wire Size 4.00mm2 10.00mm E6012GR EN61018 (12mm) Wire Size Wire Size 26.00mm2 16.00mm .
seam butt welding resistance butt welding flash butt welding resistance butt welding shielded unshielded other process plasma laser resistance butt welding inert gas welding submerged arc welding atomic hydrogen shielded metal arc welding (coated electrode) esepl w w w . e u r e k a e l e c t r o d e s .
the welding processes most often used in today's industry including plasma arc cutting, oxyfuel gas cutting and welding, Gas Metal Arc Welding (GMAW), Flux-Cored Arc Welding (FCAW), Shielded Metal Arc Welding (SMAW), and Gas Tungsten Arc Welding (GTAW). Flat welding positions and basic joints will be practiced. Pipe and tube welding
3. Classification of Underwater Welding Underwater welding may be divided into two main types: a) Wet welding b) Dry welding Fig. 3.1 Classification of underwater welding 3.1 Wet welding 3.1.1. Wet welding with coated electrode Wet welding is performed at ambient pressure with the welder-diver in the water and no physical barrier
CURRICULUM VITAE : ANN SUTHERLAND HARRIS EDUCATION B.A. Honors (First Class) University of London, Courtauld Institute 1961 European art and architecture, 1250-1700 PhD. University of London, Courtauld Institute 1965 Dissertation title: Andrea Sacchi, 1599-1661 EMPLOYMENT 1964-5 Assistant Lecturer, Art Dept., University of Leeds. 1965-6 Assistant Lecturer, Barnard and Columbia College. 1965-71 .
