Flux Core Arc Welding by Steve Bleile

[Applause] [Applause] [Music] and [Applause] hi my name is Steve bleiel and I'm a welder both for its speed and ease of operation wire feed has become the standard in the welding industry with the availability of smaller diameter wires and less expensive welding machine semi-automatic wire feed processes are now common in smaller shops on farms ranches and even in Home shops today we're going to look at flux core arc welding this process uses a continuous tubular wire that surrounds an inner core of flux compounds added to this flux determine the characteristics of the arc and well build up during the weld these compounds clean oxides from the surface of the metal helping the bolt pull the flow out they also lift oxygen nitrogen and other impurities from the molten filler metal producing a clean weld deposit as a molten flux cool it forms a protective slag covering over the hot weld bead now in any type of welding the molten metal needs to be shielded so that it doesn't come in contact with oxygen and nitrogen in the surrounding air flux core arc welding shields the molten metal two different ways depending on the type of flux core wire self shielded or gas shielded and these really are like two different processes with the self-healing wires the molten weld puddle is shielded by gases created from the burning flux these wires typically require less voltage can be used over a wide range of metal thicknesses and deliver a moderate deposit rate social inflex core wires provide a wire feed process that's relatively mobile it can be used outside of a shop for structural general fabrication and repair socialist flux core wires are extremely versatile and for beginners it's probably the easiest type of welding to learn and use with casillas flux core wires the compounds in the flux did not produce a gas is necessary to protect the molten metal from contacting the surrounding air so an externally furnace shielding gas is needed these wires generally require a higher voltage considered most efficient on thicker metals and provide high deposit rates because of the external shielding gas these wires are used inside of a shop or some confined area for heavy fabrication and equipment repair both self-healing and gas Schilling wires have the potential to produce strong weld there are differences between the two both and setup and welding techniques so let's start with self shielded flux core arc welding so shielded core wires were originally developed as an alternative to shielded metal arc welding which is stick rod with higher deposit rates wire feed is more efficient it's also easier to use especially for beginners in electric arc welding the distance between the electrode and the metal called the arc gap is extremely important any change in the length of the arc will affect the amount of heat at the weld with the wire feed process when the voltage and wire speed are set properly the welding machine automatically maintains a uniform arc even with slight variations in the position of the wire feed gun you can run a weld be the very first time you pull the trigger but there is a little more to joining metal and just squirting wire while the equipment does feed wire and maintain the arc the welder still needs to control the position of the wire feed gun the direction of travel and the travel speed there's also metal preparation and joint fit up to use wire feed effectively requires the physical ability to control the wire feed gun along with a basic understanding of the equipment and welding wires a standard setup for the self-healing flux core wires consists of a power source a wire feed unit the gun assembly and a ground clam smaller wire feed machines up to 200 amps will generally have the power source and wire feed unit combined the welding industry wear more powerful equipment is used the wire feed unit may be separate from the power source our feed Welling machines may look different depending on the size and brand name but they all do the same thing feed wire and regulate current so basically they all have the same parts social inflexible wires are typically used with a constant voltage direct current power source alternating current from the wall outlet is transformed into direct current to the electrode which is the welding wire the direction of flow referred to as polarity is determined by how the leads are connected to the terminals on the welding machine for direct current electrode negative or DC minus the lead to the wire feed gun is a attached to the negative terminal and the ground clamp is attached to the positive in theory negative electrons flow from the welding wire striking the base metal and forming the molten puddle quickly electrode negative is generally associated with lower voltage requirements and faster travel speeds with direct current electrode positive or DC plus the lead to the wire feed gun is attached to the positive terminal and the ground to the negative current flows from the metal to the wire the more weld puddle is formed by hot gases surrounding the arc electrode positive generally requires higher voltage settings and slower travel speeds so shielded flux core wires are developed to run on a specific polarity some use electrode negative others use electrode positive it is important to set up the equipment for the polarity of the wire you're using wire feed also uses a constant voltage power source this is different from a stick rod welding machine which uses a constant current power source during the well either the voltage or the amperage is always changing to maintain the arc in wire feed welding this mainly happens when the gun is held closer or further from the metal with CV power sources the voltage is set while the amperage barry's to provide the current necessary to burn off the wire and maintain the arc constant voltage power sources stabilized quickly maintaining a uniform arc length and allowing the drive rolls to feed the wire at a constant speed in some situations a constant current power source can be used along with a voltage sensing wire feed unit with a constant current power source the amperage is said and remains fairly constant while the voltage varies to maintain the arc special wire feeder units often referred to as suitcase models are designed to sense the voltage changes and vary the wire speed to maintain a uniform arc length both each sensing wire feed units are typically used that work best with bigger welding machines and larger diameter wires the water heater unit itself either constant speed or voltage sensing fairly simple there's a spindle to hold a roll of wire with the catch that's inserted into a hole in the back of the spool the spring-loaded nut at the end of the spindle should be tightened just enough so the spool stops when the drive will stop and it doesn't continue from momentum drive rolls are designed to match the diameter of the wire indicated on the side of the rolls the gun assembly contains a liner for the welding wire a lead supplying current to the contact tip and control wires attached to the gun trigger at the end of the gun there's an adapter the contact tip and a thread cover to protect the threads on the adapter the contact tip is the last part of the welding machines electrical system that energizes the wire tips are available with different sized openings and for good contact you want the tip to match the diameter of the wire to load the wire not the rolls for the wire comes off relatively straight to a guide that keeps it centered in the groove on the drive roll and into a steel liner inside the gun assembly before you close the drive roll make sure the wire is centered on the groove and tighten just enough to keep the wire from slipping flex cord wires which are relatively soft can be deformed if the drive rolls are over tightened with the school loaded lower the hood turn the machine on straighten the lead up a little and pull the trigger there is a very close tolerance between the opening and the contact tip and the wire diameter you may want the contact tip removed until the wire is all the way through then reinstall it and you're ready to well now part of wire feed welding is maintaining the equipment to keep the wire feeding smoothly it is very difficult to make a good well when the wire is coming out in spurts so let's look at a few things you need to pay attention to even though the wire looks clean it does cause dust from the shop to gum up the liner installing a wiper with solvent made especially for welding wire helps keep everything operating smoothly during the well small bits of hot metal called weld spatter fly out of the molten puddle depending on how clean the metal is and the position of the wealth Bobson spider may stick to the end of the contact 10 occasionally check the tip and scrape off any build-up the water can also burn back and stick at the tip so it's a good idea to keep a few extra contact tips on hand wire feed machines are well built in the most cases feeding problems are not equipment failure but rather some kind of contamination either dust from the shop or weld spatter take the time to keep the Machine clean and the wire feeding smoothly since the 1980s once self shielded flux core became popular new wires have been developed to make this process more versatile and easier to use welding wires are classified by the properties of the finished weld the e stands for electrode the seventh indicates the weld metal has a 70,000 pounds per square inch tensile strength and tensile strength as the force it takes to pull it apart the one indicates the wire can be used for welding in all positions flat horizontal vertical and overhead a 0 like an e 70 t for the wire was designed for welding in a flat position only or for horizontal fillit the T stands for tubular indicating it is the cored wire the last number refers to the characteristics of the arc and the properties of the weld depending on the type of flux social wires can provide deep penetration or build up more well some are limited to single pass only others can be multi passed for larger wells keep in mind most wires were developed for industry where wells are often made in the same position or specific mechanical properties are required a 70 T 3 and T 10 or high-speed single pass wires East 70 T 4 and T 7 are multi pass wires with high deposit rates each 70 t6 and E 71 T eight are multi pass deep penetrating wires that meet the impact requirements for welding structural steel in seismic zone for general-purpose fabrication and repair in all positions a 71 TGS is often used with a lower voltage hobbyist type wire feed machines these are recommended for a single pass weld with limits on the amount of well build up each 71 T 11 one of the most commonly used self shielded wires can be multi passed but is often limited to a well build up of 3/4 of an inch with a smooth arc and spray metal transfer East 71 T 11 wires provide good weld fusion and are very easy to use in any welding position this is the type of self shielded wire we'll be using for our demonstrations the diameter of the wire is selected for the amount of filler metal deposit and in some cases the size of the welding machine in the welding industry larger diameter wires provide maximum weld deposits in the flat position smaller wires are used for vertical and overhead wells depending on the thickness of the metal for general purpose welding where you're working with different metal thicknesses in different welding positions it's more of a compromise Oh 300 works well for the thinner gauge metals Oh 35 is used when the metal is mainly a quarter of an inch or less and both of these are commonly used with the smaller wire feed machines over five and larger wires are used for metal that's a quarter of an inch and thicker these are generalizations if you can handle more metal try a larger diameter wire if you're doing a lot of vertical and overhead you can always use a smaller wire for less well deposit and better control one last thing about flux core wires these are classified by the finish weld and the way manufacturers achieve this varies some wires even in the same classification may be easier to use than others if you seem to be having a problem you may want to try a different brand of wire okay we've set this machine up with e 7 t 1t 11 all positions self shielded core wire let's try some welding before you pull the trigger and throw sparks all over the place cover yourself up or some good gloves a hat and always wear safety glasses along with hot metal sparks flying around slag or other impurities can pop from the surface of the metal as it's heating up or cooling make sure the lenses in your welding hood are clean use clear lenses to protect the shaven lens and check that everything is sealed so light doesn't leak around the edges inside the hood keep your work area clean and always have a fire extinguisher handy ideally the ground clamp should be attached as close as possible to the well that's not always practical sometimes it's attached to the work table or further away on a structure fabrication or piece of equipment but it is important to have a good clean ground so our splutters at the beginning your left the arc seems like it does I'm going to start check the ground connection trim the wire a quarter to three eighths of an inch from the end of the contact tip get comfortable and use both hands on the wire feed gun so you can be as steady as possible when you pull the trigger circuit to the power source provide current to the wire and the drive rolls start to feed wire when the wire touches the metal the arc is started the shape and amount of wealth along with penetration and weld fusion are controlled by the distance the gun is held from the metal the angle of the wire feed gun the voltage and wire speed settings and the travel speed during the well you have to focus on the molten puddle constantly analyzing how fluid it is how the edges are slowing out and watching the weld build up even though the welding machine does automatically maintain the arc length the amount of wire that sticks out from the end of the contact tip to the metal call electrode extension or wire stick out will affect the amount of heat at the weld CV power sources try to maintain a constant voltage then provide the amperage necessary to burn off the wire longer electrode extensions allow the wire to preheat reducing the average necessary to burn it off and reducing the heat at the well shorter electrode extensions cause the amperage and heat to increase depending on the specific wire and wire diameter the recommended electrode extension can range from a half an inch to two and a half inches for the smaller East 71 T 11 self shielded wire we're using the wire stick out from the contact tip to the metal should be around a half to one inch for a smooth weld bead you want to maintain a consistent wire stick out well you want to avoid holding the gun closer which can agitate the public one of the unique characteristics of the self shielded flux core wires is that you can pack the gun away to fill gaps in poorly fit joints you need to watch the pole though keeping it hot enough so the molten metal flows out on the side under normal welding conditions the gun can be held anywhere from nearly perpendicular to around a 15 degree angle back towards the well this is referred to as pulling the well when the gun is held more perpendicular the arch stream is directed right onto the metal causing the puddle to form and spread quickly this can be used with a faster travel speed to limit penetration on thinner metal or for making smaller weld beads does the gun is angled back towards the well some of the heat is taken off the metal this allows a slower travel speed to build up more wells without overheating the base metal you do want to avoid angling the gun too much all the heat will be directed back on to the public limiting penetration and possibly overheating the molten filler metal whether you're holding the gun up to spread the puddle or angling it to build wealth try to maintain a consistent gun angle for a smooth weld bead for most Wells you can just move the gun in a straight line the consistent wire stick on and travel speed will produce a uniform well you can also use a slight side-to-side motion watching the outside edges to make sure the total is slowing out as you gain experience you can use more gun movement to deposit more metal and avoid big wide gun movements that make the puddle more fluid and difficult to control either running straight or using a little gun movement you want the wire and the arc directed at the leading edge of the molten puddle this not only helps ensure good penetration and weld fusion it keeps some old flag back over the well this is very subtle but wherever wire hits a puddle makes a huge difference if the wire is directed back further the weld buildup limits the amount of heat that's transferred to the base metal reducing penetration also pushing the puddle in front of the wire increases the chances of trapping slag under the weld bead try to keep the wire towards the leading edge of the puddle using the gun angle and direction of travel to keep the mould filler metal and slag behind the wire the voltage and wire speed settings are the main control of the potential amount of heat and size of the well there are two parts to making the final adjustment first for penetration and wealth fusion the arc has to produce enough heat to melt the base metal while the filler wire is continuously added to the molten puddle when the voltage and wire speed are set to low the base metal does not get hot enough to melt so the filler metal just stacks up on top there's a voltage and wire speed or increase a mould pull forms flowing out to the sides the filler metal is fusing to the base metal the well is starting to penetrate and you have control of the edges of the poem increasing the voltage and wire speed spreads the molten puddle the filler metal becomes more fluid and produces a smoother finished weld bead eventually the puddle and base metal become too hot making the well build up extremely fluid this range from the point where the puddle is formed to the point where the filler metal is overheated is referred to as parameters typically voltage and wire speed parameters are fairly wide leaving the final settings up to the individual welder depending on metal thickness weld position and the level of skill what's the amount of heat and well deposit is determined the second part of adjusting the voltage and wire speed is tuning the arc length to provide a stable transfer a filler metal into the molten puddle this adjustment can be made on some practice metal adjusting either the voltage or the wire speed as long as the dial is a rheostat and infinitely adjustable if the dial clicks in the ranges you cannot change it during the weld watch the tip of the wire looking directly at the arc length if the wire speed is too fast to the voltage the wire will run into the puddle kind of exploding and causing excessive weld spatter but the wire speed is too slow the arc length is increased causing the puddle to whine then slamming the weld build up the voltage and wire speed should be tuned for a short arc length right above the surface of the metal experiment with the voltage in wire speed watch the arc length the puddle and examine the finished weld bead most welding machines provide a chart with recommended settings as your welder skills improve you can increase the voltage and wire speed for higher deposit rates better penetration and smoother weld beads the travel speed how fast you move the gun also affects the amount of heat at the weld if the travel speed is too fast the metal doesn't have time to heat up the Welby will stack up on top with limited penetration in weld fusion traveling too slow will generally put the wire and the arc on the weld build up causing excessive filler metal deposit and making the puddle difficult to control watch the puddle you need to travel slow enough to allow the mold pool to spread and at the same time fast enough to keep the filler metal from becoming excessive and overheating then maintain a travel speed that keeps the molten puddle the same slide that's about all there is to the fundamentals of welding with self shielded flux core wires set the equipment up with the correct polarity have a good clean ground use both hands on the wire feed gun adjust the voltage and wire speed to allow the molten pool to spread out and tuned for a short arc length maintain the recommended wire extension with the wire directed towards the front of the poem use the gun angle and travel speed to control the amount of weld deposit then travel at a speed that maintains a uniform weld puddle so far all the demonstrations have been in the flat position for a horizontal we'll be welding a cross angle the gun up a little and slightly back towards the weld bead watch the top side of the puddle and the weld build up maintain a recommended wire extension travel slow enough to allow the puddle to flow out but fast enough to keep the filler metal from sagging if the weld build-up does sag either the base metal or the filler metal is overheating try traveling a little faster make sure you're not handling the gun too far back into the weld vertical welds are made either uphill or downhill depending on a specific wire some opposition self shielded wires because of the type and amount of slag are designed for uphill only in the vertical position with the general purpose East 17 111 wires downhill can be used on thinner gauge metals to limit penetration angle the gun up slightly using the force of the arc to help hold the PUD alone either running straight or using a slight side-to-side motion travel fast enough to stay ahead of the well build up watch the sides to make sure the pole is flowing out and to keep the weld bead straight traveling downhill limits penetration and will produce a flatter weld bead for heavier metal wear more well build up is required be 71 t11 can be run uphill hold the gun nearly perpendicular to the metal if you're using a slight zigzag motion or running straight travel fast enough to keep the weld build-up from spilling down you may want to use the slightly lower voltage in wire speed but not too low as many problems are caused by running to coals by running too hot for welding uphill it is important to have the voltage and wire speed tuned for a short arc length and to maintain a consistent wire extension watch the sides of the puddle and the filler metal build-up to keep the weld bead uniform overhead wells are just like flat wells hold a gun nearly perpendicular to the metal or even slightly angled back towards the weld maintain a uniform wire extension and travel speed keeping the wire on the leading edge of the puddle as long as you don't overheat the base metal or the weld puddle the molten filler metal will stay right up there the real challenge of welding overhead is finding a comfortable position so you have complete control of the wire feed gun if the wire extension gun angle or travel speed varies the amount of heat at the well will not be constant making the POE more difficult to control so in some way to be as steady as possible while self shielded wires are relatively simple to use you do need to understand the molten weld pool and develop the physical ability to control the wire feed gun practice and examine the finished weld a uniform bead will come with experience but the edges should be tied in nicely if the bead stacks up the voltage and wire speed may be set to low the travel speed may be too fast or the gun might be angled too far back into the well excessive filler metal deposits are caused by too slow of a travel speed social influx core wires do produce weld spatter the best you can do is to make sure the voltage and wire speed are tuned for a short arc length also increasing the voltage and wire speed will help to reduce the size of the spatter if you can handle the molten puddle turn up the heat when you're comfortable running weld beads try practicing on some weld joints well there are many variations basically there are four types but joints lap joints tea joints and corner joints the first steps to making any type of well join our metal preparation and joint fit up clean any dirt paint or grease and whenever possible even the mill scale from the surface when you cut the metal keep the edges straight and square and if you're fitting up with a gap try to keep it uniform you can avoid a lot of by taking the time to get the metal ready to weld both joints are joining the edges of the metal and this can be on plate flat bar angle irons pipe or square tubing on thinner gauge metal around 1/16 of an inch thick but the pieces together trying for a perfect fit any gaps may cause the edges to meld away ripping open a hole if possible try to position the thinner gauge metals to weld downhill with downhill you're welding away from the heated metal limiting penetration and helping to avoid burning through as the metal thickness increases you want the amount of filler metal to equal the thickness of the base metal weld does need to penetrate deep especially if there's any stress on the joint or you intend to grind the weld for a polished finish for metal that's around an eighth of an inch thick try leaving a small gap approximately a sixteenth of an inch and keep it uniform if the pieces were fit up without a gap take a grinder up on edge and grind a groove to allow for penetration when the metal is around 3/16 of an inch and thicker bevel the edges of the piece is being joined bevel should be around a thirty degree angle with a flat spot called a landing on the bottom the landing helps prevent the bottom edges from melting away pack the pieces together with a uniform gap then grind the edges of the tacks in the amount of gap depends on whether or not complete penetration is required if 100% penetration is not necessary use a narrow gap with a gun held more perpendicular where in the first pass deep in the joint making sure the puddle flows out and ties in on the side for complete penetration use a slightly wider gap start the arc and move to the front of the tack on the bottom edge of the bevel bring the wire across slightly back on the puddle to the edge of the pedal on the other side then just back-and-forth stay deep in the joint once the first pass is in clean off the slag with a chipping hammer and wire brush anytime you weld in a bevel you want the filler metal buildup uniformed if there's high spots from stopping and starting use a grinder up on edge to even up the weld depending on the metal thickness you may be able to finish in one more pass with the gun angle then a slower travel speed build up weld slightly wider than the bevel and above flush with the surface for heavier metal run as many beads as it takes clean the joint after each pass and overlap the edges of the weld beads to avoid trapping flag on lap joints where one piece overlaps the other the weld is called a fill it the goal is to melt and fuse the bottom corner and the weld should come up and out a distance equal to the thickness of the metal with the bead slightly crowned there are two wire feed gun angles that you have to consider fulfill it weld the work angle in relation to the pieces of metal and the drag angle which is relative to the weld bead itself the work angle controls the position of the weld in the joint and the angle will vary depending on the thickness of the metal on thin gauge metals the top piece will heat up and melt faster than the bottom direct the wire and the heat onto the bottom piece allowing the puddle to flow out and tie into the top as a metal thickness increases direct the wire into the bottom of the joint with the wire feed gun angle to help push the puddle up the drag angle affects the shape of the weld bead holding the gun more perpendicular to the weld allows a faster travel speed it produces a flatter bead with a gun angled slightly back towards the weld a slower travel speed can be used to build up more well avoid angling the gun too much the heat of the arc will not be directed onto the base metal limiting penetration to melt and fuse the bottom corner keep the wire towards the leading edge of the poem for more Wells buildup on heavier metal you can either increase the voltage and wire speed or stack overlapping weld beads to provide a required amount of weld posit a philip weld is also used for t joint and this is similar to a lap well in the horizontal position direct the wire at the bottom piece right in the corner of the joint with a gun angle to help push the puddle up maintain a uniform wire extension and travel speed for a smooth weld bead as you gain experience you can use a little gun movement to deposit more metal always keep the wire directed into the pole and bring the wire back to the leading edge to ensure good penetration and stay ahead of the puddle for an overhead filling angle the gun to push the puddle up hold the gun nearly perpendicular to the well for a flatter beat or angle very slightly back to carry more metal for vertical fill it's try welding downhill with be 71 T 11 on thin gauge metal to limit penetration on heavier metal run uphill stacking overlapping weld beads as you gain control you can use some gun movement to deposit more metal I'm vertical up for the first pass deep in the corner hold a gun nearly perpendicular to the metal bring the wire out to the side making sure the puddle flows out and ties in then move back into the corner and over to the other side pay attention to the wire extension moving the gun into the corner to maintain a uniform wire stick out if you just come across the wire extension will increase in the center then shorten on the sides try to maintain a consistent wire extension to keep the amount of heat uniform if you need more well deposit you can overlap smaller beads or try running a weave bead starting on one side let the puddle flow out move across to the other slide hesitating if necessary to let the puddle flow out then cross back and forth keeping the wire extension and travel speed uniform and the upward progression tight watch the sides to make sure the puddle is flowing out and to keep the weld bead straight weaving takes some practice but will allow you to build up more well in vertical of position corner joints can beef it up several ways depending on how you want the finished weld to look one piece can be beveled to provide sufficient penetration if the pieces were fit up without a bevel use a grinder to groove that joint for ornamental type projects this type of fit up can be polished for a nice square corner corners can also be set up by budding the inside edges of square cut angle the gun right into the bottom and adjust the travel speed so the puddle spreads all the way to the top and the bottom if you can't fill the corner with one pass try running the first bead filling to the bottom edge then making a second pass filling to the top on heavier metal stack as many beads as it takes for ornamental projects this can be polished for a round corner or grounds flat for a beveled look if you're concerned about the strength on any type of corner joint you can run a fill up weld on the inside but this will cause the pieces to draw in the direction of the filling whenever possible try to make the outside weld first whether you're fabricating with new metal or making repairs always remember that every weld joint is made one weld bead at a time understand the characteristics of the specific welding wire you're using take the time to get the metal ready to weld set the voltage and wire speed high enough to allow the puddle to spread out tune together for a short arc length watch the edges of the puddle and the weld build up then travel at a speed that maintains a uniform weld puddle maintain the recommended wire extension using the gun angle and travel speed to control the amount of filler metal deposit and the shape of the weld bead [Music] - ulid flux core arc welding is the main semi-automatic wire feed process used in the welding industry for heavy fabrication high deposit rates ain't good weld fusion one with ease of operation also make this an excellent process for the in shop repair of farm and construction equipment - shielded flux core wires required externally furnace shielding gas that prevents oxygen and nitrogen in the surrounding air from coming in contact with both the filler metal as its transferred from the tip of the wire and the molten weld puddle in addition compounds added to the flux and the welding wire called deoxidizers hell remove surface oxides and other impurities from the weld puddle as a load cooled a slag covering is form that continues to protect the hot weld bead from contacting the surrounding air this combination of shielding gas flux deoxidizers and the slag covering produces cleaned filler metal deposits even on larger wells - ulid flux core uses the same type of wire feed unit and direct current constant voltage power source as the self shielded wires because higher voltage and amperage is required power sources typically range from 300 to 400 amps smaller machines down to 200 amps can be used but are limited to the smaller diameter wires the wire feed machine also contains a gas delivery system along with a shielding gas cylinder and flow meter if you're straight carbon dioxide or a blend of 75% argon and 25% co2 is used with many of the gas shielded wires straight carbon dioxide is less expensive and produces a high energy arc stream that provides good penetration and weld fusion co2 is typically used in the welding industry with welding wires designed for the flat position because argon transfers current better a 7525 shielding gas allows a slightly lower voltage resulting in a smoother art and making the weld puddle easier to control 7525 is commonly used with a gas shielded flux core wires designed for all position welding these are high pressure bottles and can be filled to over 2,000 pounds per square inch you need to protect this valve from getting damaged so when the bottles in use it needs to be changed securely and when it's not in use or you intend to move the bottle use the protective valve cover even when the bottle is empty the flow meter regulates the amount of gas flow measured in cubic feet per hour there are different styles of flow meters with a high pressure gauge indicating the pressure inside the bottle and the other gauge used to adjust the flow of gas the gas delivery system includes a solenoid inside the machine that allows the gas to flow when the wire feed gun trigger is pulled and a hose inside your gun assembly at the end of the gun you have an insulator an adapter sometimes called a diffuser the contact tip and the nozzle contact tips come with different sized openings to match the diameter the welding wire and in different lengths for gas EULA flux core welding the contact tip should be recessed approximately half an inch from the end of the nozzle the gas flowing around the tip helps keep it from overheating during the well spatter flying out of the molten puddle will collect on the inside of the novel possibly disrupting the flow of gas check this occasionally you clean out any buildup of weld spatter - shielded welding wires are classified by the chemical and mechanical properties of the finnex well II 70 T 1 and E 71 T 1 are the most common wires for welding on carbon steel both run on DC electrode positive and have a 70,000 pounds per square inch tensile strength indicated by the seven the zero in east 70 t1 indicates wires designed for welding in the flat position and for horizontal Phillips with a co2 shielding gas these are typically used in the welding industry for extremely high deposit rates the one in East 71 p1 indicates an all positional welding wire and is commonly used both in the industry and smaller shops with a 7525 gas blend for general purpose fabrication and repair every manufacturer does several choices of wires in the t1 classification some wires have more deoxidizers for welding on metal at slightly rusted or they're designed to run with a specific shielding gas the welding wire and wire diameter is selected for the type egg conditions of the project you're working on to load the wire trim the wire cleanly avoiding any bends of birds before you close the drive rolls make sure the wire is centered on the groove and tighten just enough to keep the wire from slipping with the spool loaded close the hood turn the machine on and pull the trigger when the wires all the way through install the contact tip and the nozzle to open the shielding gas bottle and adjust the flow meter crack the valve slowly to avoid hammering the internal diaphragms in the flow meter then open the valve all the way high pressure bottles have two seats one to close the bottle and the other to seal the valve stem when the bottle is open so open the valve all the way regardless of which type of flow meter you're using you'll get a more accurate reading with the gas flowing so pull the trigger on the wire feed gun to make the adjustment the gas flow setting depends on the size of the weld puddle and the surrounding conditions the idea is to use the minimum amount necessary to shield the weld puddle there's not enough coverage void called porosity can form in the weld bead too much flow can have a cooling effect and create turbulence making the weld puddle more difficult to control generally 30 to 40 cubic feet per hour is sufficient for the smaller wires and 40 to 60 cubic feet will provide coverage for the larger wires some industrial machines will have a spool and purge button the spool button activates the drive rolls to feed wire without opening the shielding gas solenoid this is handy for loading while working on feeding problems the purge button allows the gas to flow without activating the drive roll and can be used to adjust the flow meter without running out excessive amounts of wire oK we've loaded some East 17 1t1 all position welding wire with a 75 25 shilling gas and even though this type of welding wire runs hot produces big wells with high deposit rates gashel and flutter arc welding is very simple just like every other semi-automatic wire feed process the wire extension gun angle direction of travel and the voltage in wire speed all work together to control the amount and shape of the weld deposit be 71 t1 flux core wires have a spray type metal transfer electrical energy breaks the filler wire into small droplets that are sprayed across the arch stream if the voltage and wire speed are set too low there's not enough energy to break up the wire the filler metal is transferred in globs that can escape the arc stream causing excessive weld spatter as a voltage and wire speed are increased the arc smooths out and the molten puddle becomes more controllable recommended voltage and wire speed parameters are available from the manufacturers of the wire but the final settings are determined by the metal thickness weld position and level of welders skill in the flat position high voltage and wire speeds can be used to produce more weld deposit for vertical and overhead slightly lower settings keep the amount of heat and filler metal deposit more controllable the voltage and wire speed also need to be tuned together in the welding industry the wire speed is usually adjusted to provide the quantity of weld required the voltage which controls the length of the arc then adjusted for a short arc length make some practice wealth looking directly at the tip of the wire if the voltage is set too low the wire will appear to run into the puddle causing excessive well spatter when the voltage is set too high for the wire speed the arc length increases making the molten puddle extremely fluid and difficult to control to the voltage for a short arc length just above the surface of the metal having the voltage and wire speed adjusted together helps reduce the amount of wealth spatter it makes a big difference in having control of the molten puddle especially when you're well the vertical and overhead positions for 71 t1 wires recommend an electrode extension which is the distance from the end of the contact tip to the middle is approximately three-quarters of an inch to an inch and a quarter with gas shielded flux core arc welding the contact tip should be recessed about 1/2 an inch this not only helps keep the tip cooler it also places the nozzle closer to the metal ensuring good shielding gas coverage while maintaining a recommended electrode extension during the weld try to maintain a consistent wire extension even though the welding machine will maintain the arc varying the position of the wire feed gun will set the amount of heat at the weld with a constant voltage type power source longer electrode extensions allow the wire to preheat reducing the amperage necessary to burn off the wire and cooling down the weld puddle a shorter electrode extension increases the average agitating the molten puddle for a uniform penetration and a smooth weld bead maintain a constant wire extension in the flat position where you can handle more metal use the upper end of the voltage and wire speed parameters with a gun angled anywhere from straight up and down to about 15 degrees pull the well making sure the molten slag and filler metal stay behind the wire watch the puddle adjusting the travel speed to allow the molten metal to flow out on the side but fast enough to avoid excessive filler metal buildup because of the high amount of heat and filler metal deposit try running straight without any gun movement keep the wire directed towards the leading edge of the puddle if you think you can handle more metal try increasing the voltage in wire speed for the vertical weld position be 71 t1 is run uphill only set the voltage and wire speed in the lower range of the weld parameters with the wire feed gun they're like perpendicular to the metal may be angled up slightly try traveling straight up without any gun movement maintain a Const wire extension to keep the amount of heat at the weld uniform watch the edges and the filler metal deposit traveling up fast enough to keep the build-up from spilling down if you have problems with uphill make sure the voltage and wire speed are set high enough and tuned for a short our claims horizontals are welding across but the voltage and wire speed set in the middle of the welding parameters angle the gun up slightly try starting with the gun nearly perpendicular to the weld as you gain experience and control you can angle the gun slightly back into the well to carry more metal watch the top of the pub to keep the weld straight and watch the weld deposit traveling fast enough to keep it build up from sagging if the weld deposit does sag make sure you're not angling the gun back into the weld too much then try increasing the travel speed to keep the base metal and weld puddle cooler overhead wells are just like flat welds the real challenge is finding a comfortable position so you have complete control of the wire feed gun try holding the gun nearly straight up and down may be angled very slightly back towards the well when you maintain the recommended wire extension and a uniform travel speed the molten filler metal will stay right up there on an overhead you need to keep the base metal and weld puddle from overheating if the voltage is not adjusted for a short arc length or the gun is angled back into the weld too much the molten puddle will become so fluid it may drip also if the travel speed is too slow the base metal can overheat which causes the puddle to become more fluid and difficult to control hold the gun nearly straight up and down keep the wire towards the front of the puddle and watch the weld build up traveling fast enough to keep it from becoming too fluid regardless of the weld position flat vertical horizontal or overhead set the voltage and wire speed high enough for a spray transfer to the voltage for a short arc length maintain the recommended wire extension and provide a sufficient amount of shielding gas to cover the molten puddle problems arise when you try to well outside of these parameters excessive well spatter can be caused by the voltage and wire speed set too low or the voltage you set too low for the wire speed allowing the wire to run into the puddle porosity which is voids in the weld from gas pockets is generally caused by impurities like dirt rust or paint on the surface of the metal porosity also results from losing the shielding gas coverage either not having enough slope or holding the wire feed gun too far away from the metal worm tracks are lines created by gases trapped on top of the weld bead as a flux solidifies these are typically caused by using too high of a voltage and wire speed along with traveling too fast they can also be caused from an incorrect wire extension take the time to practice experiment with the voltage in wire speed setting learn to control the amount of weld deposit and develop the skills to maintain a uniform wire expansion and travel speed - shielded flux core is typically used on heavier metal for structural and equipment fabrication or repair metal preparation and joint fit-up are extremely important clean any contamination like dirt rust paint or grease from the surface of the metal even the mill scale whenever possible because of the amount of heat and well deposit gas shielded flux core does not work well for filling gaps keep the edges of the metal straight and avoid excessive gaps turn fit up a butt joint metal preparation and fit-up depend on whether partial or complete joint penetration is required 100% penetration is not necessary prepare the bevels with a small landing to help prevent the bottom edges from melting away pack the pieces together with a sixteenth to three thirty second gap holding the gun a little more perpendicular to the metal and the wire directed towards a leading edge of a puddle put the first pass deep in the joint making sure the puddle flows out the ties into the sides of the bevel when complete penetration is required you can use the same type of fit up running the first pass as deep as possible then grinding or gouging the backside the clean metal and running a weld bead above flush a V bevel with a back up bar can also be used for complete penetration weld prepare the bevels with a feathered edge grind the middle scale off the backup bar and fit the pieces with a 3/16 to quarter inch gap either staggering tax on the backside or tacking in the bevel if you do tack in the bevel grinding starts and stops thin for the first pass keep the wire in the center making sure the puddle stays behind the wire and flows out tying in on the slides if you direct the wire onto the sides of the bevel the filler metal can actually float across not fusing the bottom edge of the bevel after the first pass run as many beads as it takes to fill a cap slightly wider than the bevel and above flush with the surface on heavier metal plan the well using the travel speed and gun angle to control the amount of weld deposit feel slightly below flush leaving the top corners of the bevel as a guide for the final passes to cap a wide bevel overlap weld bead side by side with a wire feed gun angle a little to build up well use the edge of the bevel to keep the bead straight then use the inside edge as a guide adjusting the travel speed to allow the puddle to flow almost to the middle of the first pass it's a final pass needs to be smaller hold a gun more perpendicular and increase the travel speed for a narrower bead in any welding position flat horizontal vertical or overhead running hot and straight stacking as many beads as it takes is the simplest way to fill in cap heavier metal a Filat weld is used on both lap joints and t joint and the techniques for both is very similar direct the wire into the corner slightly towards the bottom piece the work angle determines the position of the fill it in the joint angle the wire feed gun to help push the puddle up holding the gun more perpendicular to the weld will produce a flatter bead and when necessary allow you to travel faster for less welds upon angling the gun slightly back will build up more well that produces slightly crowned weld bead keep the wire towards the front of the puddle for good weld fusion in the bottom corner on heavier metal stack up overlapping beads but build up the required amount of weld fill it wells are pretty easy with gas shielded flux core just make sure the puddle and slag state back behind the wire with molten metal floats in front of the wire and you push the pole there's a good chance in the bottom corner will not be fused quarter joints can be fit up with one piece bevel or by budding the inside edges of square cuts on thinner metal to open the bevel up so you can control the puddle in the bottom of the joint on heavier metals a smaller bevel is often used to reduce the amount of weld deposit and time takes to complete the joint the beveled side is going to heat up quicker angle the gun as necessary to allow the puddle to flow out and tie into both pieces on an outside corner because of the amount of heat and filler metal deposit well will try to say for thinner metals holding the gun more perpendicular to the weld along with a faster travel speed will help keep the base metal and molten puddle cooler as the metal thickness increases it may take two passes the first filling to the bottom corner the second filling to the top on heavy metal bring the filler deposit up and out evenly leaving a little of the edges for the final well every type of weld joint in any position is made one weld bead at a time and it always comes back to controlling the wire extension gun angle and travel speed even though it's hot with a considerable amount of weld deposit gas Ulik flux core is not complicated don't be bashful turn up the heat run straight and keep it simple well I hope I've given you an idea about flux core arc welding with moderate deposit rates the self shielded wires are used for structural fabrication and repair outside the shop they're also an excellent type of wire for the smaller wire feed machines - viola wires with higher deposit rates are used inside the shop for heavy fabrication and repair choose the type of wire for the projects you're working on and understand the characteristics and parameters are the specific wire you're using watch the puddle and practice developing the skills to control a wire feed gun and figuring out just what works for you take your time have fun with this and above all else work safely [Music]

Channel: Novikov Special Materials (ООО НСМ)

Views: 115,918

Keywords:

Id: bA1ON_Y2tVo

Length: 58min 4sec (3484 seconds)

Published: Mon Dec 16 2019