TIP TIG Welding is always better quality than TIG and 100 to 500% faster with superior quality than TIG - MIG - FCAW.

MIG Welding Spray & Pulsed
Transfer Steels >3 mm.


© 2001 WeldReality.com

www.weldreality.com and tiptigusa.com

HAVE YOU SEEN TIP TIG? THIS PROCESS PROVIDES LESS WELD HEAT AND BETTER
WELD QUALITY THAN TIG AND PROVIDES THOSE WELDS AT MIG WIRE FEED RATES.




Click on the Evolution of TIG icon if you want a TIP TIG brochure.

<2006: SPRAY TRANSFER: Thanks to aggressive weld equipment salesmanship and lets face it, too common weld management and engineering "process apathy", during the last 25 years the biggest selling MIG welding power source for carbon steels / stainless robot welds has been a pulsed MIG unit, which is really ironic as 15 of the last 20 years the pulsed equipment did not work the way it was intended, and the costly, erratic pulsed equipment provided for the majority of steel applications, no real world weld benefits.

Many of the companies using pulsed MIG to robot weld steel parts > 4 mm, would have been better served, if they had used the more stable, consistent energy, traditional "spray transfer mode" available from the lower cost and more durable traditional CV MIG Welding equipment. This statement was true in 1998 and it's still a weld reality in 2010.

In a welding company that has not
implemented Best Weld Practices.
and Welding Process Control's,

you won't have to look far to find someone
in welding management who is not suited to there role.

2007: IN A CONFUSED GLOBAL MANUFACTURING INDUSTRY, IT'S EASY FOR MIG WELDING EQUIPMENT MANUFACTURERS TO SELL POWER SOURCES THAT PROVIDE USELESS BELLS AND WHISTLES:

ITS EASY TO UNDERSTAND THE RELATIONSHIP BETWEEN AN INDUSTRY IN WHICH MANY OF THE WELD PERSONNEL PLAY WITH MIG CONTROLS AND THE MAJORITY OF THE MIG EQUIPMENT SOLD IS OVERPRICED AND HAS EXTENSIVE , USELESS BELLS AND WHISTLES..


For more than five decades, the majority of global, MIG weld personnel have "played around" with a simple "two control", CV. MIG process. It should therefore be no surprise, that this process confused industry, would for the last decade perceive that the more costly and more complex the pulsed equipment the more superior this equipment was for their MIG carbon steel and stainless applications.

 

COME GATHER ROUND WELDERS WHERE EVER YOU ROAM
FOR THE TIMES THEY ARE A CHANGING:

For more than 50 years, the traditional MIG spray transfer mode has been a work horse for manufacturing companies that rarely understood what spray transfer was.

2005: The weld supervision in the auto / truck frame plants shown below, are happy to see the MIG weld sparks flying, yet this too common pathetic fire works display is an indication of weld transfer mode and voltage issues that are resulting in extensive weld quality and productivity issues.

What does a manager see when they walk past a welder?





2006: When you walk in a plant and find the manual MIG welders playing around with
their weld controls, take a look in the robot MIG welding and resistance weld cells and
you are sure to find weld production chaos and more weld rework than you should have.

A MESSAGE YOU WON'T HEAR FROM ANY
MIG EQUIPMENT MANUFACTURER:

Irrespective of the fact that MIG welding power source manufacturers and their distributors achieve much greater profits from their $6000 to $13,000 electronic pulsed equipment, the traditional 300 to 450 amp, $2000 to $3000 CV MIG equipment is still the ideal tool for most carbon and stainless steel applications and especially on carbon steel parts > 4mm.


A common MIG CV power source and wire feeder package like this Miller unit, will sell in the USA for $2000 to $4000. From a durability perspective, the CV power source should readily outlast the pulsed power source by at least 10 years, and this MIG power source will not need an electronics engineer to make repairs when required.

If you have no sense of humor, you
are in the wrong industry. An Ed joke.

< 2005: It's completely illogical to me, that the North American weld industry that erodes daily in a weld process quagmire while trying to compete with low global labor costs, has for the last two decades ignored the factors that control MIG and flux cored weld costs and , fallen over itself to pay a premium price to purchase over priced, poor performing, pulsed MIG weld equipment.

From 1985 to 2010, the global pulsed equipment typically used on carbon steel and stainless applications cost 200 to 500% more than traditional CV MIG equipment which in reality provided more weld benefits. I know it's no good harping on about the past, however perhaps it's possible that present day weld decision makers could learn from this?

 

Pulsed MIG and Spray Transfer Awareness: Pulsed MIG equipment when purchased for welding carbon steels > 5 mm, can in contrast to regular lower cost MIG equipment provide the following issues.

[a] Pulsed equipment is typically much less durable than regular CV equipment, and it's often impossible for the maintenance department to make repairs to the pulsed power source. Thanks to this fact, many companies will waste $6,000 to $12,000 and purchase an extra pulsed unit as a spare for the robot lines.

[b] Most pulsed equipment offers unnecessary bells and whistles and process / program choices and therefore adds to the general weld process confusion in the weld shop.

[c] Pulsed equipment is often used by weld personnel who don't have a clue about weld transfer mode or weld current compatibility with the part thickness or the relationship between wire feed settings, the weld fusion and weld deposition rates they could daily attain. With the pulsed MIG equipment parameter focus often on weld current rather than on the wire feed settings, you can assume that the majority of pulsed MIG welders will not be aware they may be producing;

[] welds with less than optimum weld fusion profiles,
[] welds at lower weld deposition rates than spray transfer,
[] welds with lower robot weld speeds than that which can be attained with regular spray transfer.

[d] The pulsed process which shifts between a high and "low" weld current, can on carbon steel and stainless applications > 5 mm produce welds with inconsistent weld fusion and too frequently lack of weld fusion.

Extensive data on pulsed MIG is available in the
MIG pulsed, MIG short circuit and MIG equipment sections.

< 2008: It's not just the costly Japanese and European pulsed MIG weld equipment that North American weld shops should be concerned about. If during the last decade your company purchased Miller, ESAB and Lincoln "pulsed" MIG equipment made in the USA, to weld their carbon and low alloy steel applications, they wasted thousands of dollars on unstable weld equipment that provided minimal weld quality or production benefits.

For those that doubt my words, it would take me less than 60 minutes at any facility to prove this statement. By the way you could purchase one of my weld process control books, walk over to that traditional MIG power source, set my weld data, pull down your weld shield and make a believer of yourself.

A FEW OF ED'S PROCESS OPTIMIZATION PROJECTS:

FORD F 150 FRAMES - VOLVO CABS - CORVETTE FRAMES-
HARLEY FRAMES - NEW BEETLE SEATS AND ED ALSO ESTABLISHED
THE ROBOT WELD FOR THE WORLD'S LARGEST CATERPILLAR TRUCK.

click here for Ed's best practices / process control materials.

Hopefully one day, the umbilical cord between the weld
shop and distributor salesman will be broken.


Come on chicklets miglets , we have to follow him,
after all he is the "salesman".

Experienced weld process control individuals in the majority of global manufacturing facilities have for decades been in short supply, it's therefore understandable that many weld shops became dependent on the local weld sales-rep for weld equipment or process advice, even though this individual might have a degree in the arts or english and rarely will have had management weld shop experience.

< 2008: Many of the management weld decision makers in the North American, European and Japanese welding industry have had strong opinions on their justification for the purchase and utilization of costly, pulsed MIG equipment, yet the vast majority of these persons are simply not qualified to evaluate a MIG weld process.

To correctly evaluate the pulsed mode versus short circuit or spray transfer, a weld decision maker should first be aware of the real world arc and weld differences between the traditional spray transfer, short circuit, globular transfer and pulsed mode.

Are you a process control expert?
Click here and try Ed's MIG Weld Process Knowledge quiz

Spray transfer is an "open arc" mode of weld transfer which requires specific weld parameters along with argon or argon mix.

In the spray transfer parameter range, the spray arc weld will produce a combination of weld stream and small weld droplets. The consistent energy spray transfer molten metal cascades axially through the ionized, white colored, bell shaped, arc plasma.

Note. The "medium" size weld droplets in the video shown, are transferring from an 0.045 (1.2mm) steel weld wire. The size of the weld droplets indicates that the weld transfer is in the transition parameter zone that occurs with argon mixes. This zone is found between the globular and spray mode. As the weld current is increased, the weld drops in the video that look like pulsed transfer will decrease in size and change into a continuous weld stream. Depending on the MIG gas used, the spray transition weld current with the 0.045 (1.2 mm) steel wire diameter will be approximately 255 amps.

Note: For those who want an optimum pulsed start point for any weld applications > 3 mm you would set the spray transfer 0.045 (1.2mm) transition wire feed or amps settings. This logic applies to any solid wire size.

 

The Auto / Truck Industry.
Robots, downtime and the daily Globular Weld Scourge:

MANY WELD AND ROBOT ISSUES ARE CAUSED IN THE AUTOMOTIVE INDUSTRY FROM THE USE OF OVER SIZE MIG WIRES AND ROBOT PROGRAMMERS AND UNQUALIFIED MAINTENACE PERSONNEL SETTING GLOBULAR WELD TRANSFER INSTEAD OF SETTING SPRAY TRANSFER SETTINGS.

Many robot steel weld programs that should be using spray transfer may have their weld data set in the "globular mode". The globular transfer is a common problem for auto and truck part suppliers who frequently purchase MIG wires which are too large for the application thickness or simply do not understand the root causes of globular. When the wire size is too large for the part, the spray current required for the wires will typically be too hot for the parts.

As this Ford 150 frame weld indicates, when the weld management selected an oversize MIG wire 0.052 1.4 mm) for the frame part thickness, what the unqualified management and gineers were not aware of was the minimum spray weld current required for the 0.052 wire was too hot for the gage frame parts and the pulsed parameters from the 0.052 wires and Lincoln Power Wave were inconsistent. As the Lincoln Power Wave pulsed parameters created many weld issues with the large wire, the robot personnel put the data in the regular CV mode. The CV weld parameters selected, resulted in globular transfer. On parts > 2 mm globular transfer can produce cold welds with lack of weld fusion and extensive weld spatter.

Combine the common apathetic management practice of selecting over size weld wires with the common lack of weld best practices and process control expertise on the shop floors and you are sure to have extensive robot and weld issues.

Globular transfer produces a weld transfer consisting of large weld droplets that cascade in an erratic transfer. The high energy globular weld droplets will explode when in contact with both the weld wire and work resulting in excessive, difficult to remove weld spatter.

Globular transfer is a prime cause of robot down time as the explosive weld droplets will attach themselves to the contact tip often restricting the weld wire as it exits the contact tip bore.

Globular weld transfer, not only produces excess weld spatter, it's also a prime reason for lack of weld fusion. The large globular drops lack the weld energy and plasma velocity of the conventional spray transfer. There are six primary causes of globular transfer and I cover this extensively in my process control training CD's

Weld process expertise is not rocket science,
you just have to read the right books. My grandson is on the right.

Weld Process Expertise in the Auto Truck Industry? The weld magazine publishers in the USA are well aware that the auto / truck company engineers that are responsible for arc welding robots are least likely to subscribe to their welding magazines. Even when the welding magazines are free, it's rare to find one in an auto / truck manager's or engineer's office. In the auto / truck industry why read about welding when you can pick up your cell phone and attain your weld process knowledge from a weld salesman or a slightly biased Lincoln, ESAB or Miller rep.

E-Mail.from KD - P&F.
12/07

Ed, how are you doing? You would be interested to know that by the end of the year I will have close to 100 robots welding with 0.035 (1 mm) wire using spray transfer with no pulsing. It took 10 years Ed, but we are finally using the recommendations you made in the 1990s. I now have the top Honda guy in North America convinced that instead of pulsed, traditional spray it is the way to go with many of MIG applications. In regards to your MIG process control training, we now have two plants that are interested in using your process control training resources.


Note from Ed: This E-mail was from a USA, Mid West tier one company that produces parts for Honda and Toyota. The plant has hundreds of robots and Panasonic pulsed MIG equipment. The Panasonic weld equipment and pulsed process was a requirement of the Japanese parent company. For more than a decade, the Panasonic pulsed MIG equipment generated hundreds of pulsed MIG weld issues that dramatically impacted the daily robot weld quality and production. With all the problems, the engineers in Japan were reluctant to hear that the traditional, more durable, lower cost, North American CV equipment would provide solutions to the majority of their welding issues. I guess even Japanese engineers with time (ten years) will eventually figure out the solution to simple welding problems.

The inability to establish Best Weld Practices and the general lack of
manufacturing weld process control expertise from global manufacturing managers, engineers and robot technicians is completely unacceptable when low cost, highly effective robot / manual weld process control training resources are available. Click for Ed's CD, eight hour, Process Control Training resources.



E-mail Question to Ed. 07 / 2003. From TD

Ed, We have used your training techniques at 3 of our manufacturing plants that I have worked at over the past number of years and thanks a million, they really WORK.

The other day, I got into a heated discussion with a welder, he was welding mild steel, laying 3/16 to 1/4 inch fillets. He was using 0.045. (1.2 mm) steel wire on 1/4" and 5/16" (6-8 mm) plate. The gas mix, argon - 15 CO2. He was welding with 28 - 30 volts, wire feed 250 ipm 190 - 220 amps. This welder used this one setting for all position welds - even vertical down. The arc sounded terrible ... as you can guess, he had nothing but spatter, and spent much time cleaning his welds. I tried to help him out, but he more or less told me to go back to the office where I belong. I was going to tell him to switch to an 0.035 wire, starting at about 500 ipm, set the voltage to an initial setting of about 28 volts - lay a bead, then adjust the voltage for the correct sound of the arc - slight crackle. Who is right? If I'm wrong, please let me know.
Thanks a bunch. TD.

Ed's Answer. TD. In the thickness range welded, the 0.045 wire is fine. The wire feed setting however is set in the globular transfer mode which will result in both poor penetration and lots of spatter. If he wants to weld vertical down with the 0.045 wire he should be at the start point of spray, 350-370 ipm, 260 - 270 amps (just past 12 o'clock) with 24 to 26 volts.

Vertical down welds would be easier to control with the 0.035 (1 mm) wire. For vertical down welds with the 0.035 wire, set the wire setting at 500 ipm, (just past 2 o'clock). Set 24 - 27 volts. For horizontal fillets with the 0.035 wire set 600 ipm, (3 to 4 o'clock) with 28 - 30 volts. The key to dealing with this welders process ignorant closed minded weld personnel, is first take the gun from their hands, change the weld settings and show them a better weld. You could also advice your apathetic management to provide them with what they really need, process training. Regards. Ed.

 

ROBOTS AND WELD SPEEDS: robots and weld speed.
Many companies who purchased pulsed MIG equipment for their robot cells may have had high weld speed and consistent, high weld production expectations. Some weld decision makers were under the impression that with the pulsed process and that multi-wave form, feel good fuzzy weezzy $12000 power source that they can now 'weld faster" than spray transfer on applications > 5 mm. The weld reality is this, the low cost MIG equipment that delivers spray transfer has always provided to provide the fastest weld speeds in a consistent manner on on carbon and stainless
steels > 4 mm.

When welding carbon and stainless steels under 3 mm, if you have the right pulsed >2006 MIG equipment, the present day pulsed MIG mode can provide high weld speeds. When welding parts thinner than 4 mm, the spray mode may be too hot and restrict the wire size and wire feed potential for the application.

As the world's weld shops have a few million traditional CV MIG power sources that provide traditional MIG spray transfer, the following are a few Spray Transfer Weld Facts:

[1] For those of you that believe the pulsed equipment is depositing more weld or delivering faster automated weld speeds, on applications > 4 mm, compare what you are achieving with this weld reality.

[2] With low cost, traditional, durable CV MIG equipment, spray transfer when used on parts > 4 mm typically deposits weld metal in the range of 8 - 15 lb/hr. On these applications, the pulsed MIG mode can not deposit more weld metal than spray transfer.

[3] Typical spray transfer "robot or automated 1/4 (6 mm) fillet welds" made on parts > 5 mm, are made at weld travel speeds of 18 to 23 inch/min. On these parts pulsed cannot provide faster weld speeds.

[4] When welding a 3/16 (5 mm) fillet weld, the typical weld deposition rates with an 0.045 (1.2mm) wire using spray transfer will be 10 to 12 lbs/hr with automated weld speeds for this weld in the
40 to 60 inch/min range. With extended wire stick outs, (information in Ed's "Management Engineers MIG" book) I have produced these 3/16 fillet spray welds at robot weld speeds up to 80 ipm. On parts that require 3/16 fillet welds the pulsed process will not provide faster weld speeds, however the pulsed mode can provide lower weld heat (lower distortion) and less than the minuscule spatter that results from spray.

Note: ONE OF THE FEW PULSED BENEFITS: The pulsed mode when used and set correctly, on applications less than 4 mm, can provide higher weld deposition rates than short circuit or globular transfer.

When reading weld process or equipment recommendations or articles in welding magazines, it's possible you will find a strong bias in the article. Don't forget the welding magazines get the majority of their advertising revenues from the companies that provide the majority of their weld articles.

E-mail Nov. 2004. Hi Ed. It's Matt Finn. I spoke with you on the phone a couple of weeks ago. Well contrary to the beliefs of my co-workers I must say your concepts on GMAW are worth trying. Your story of reading and more reading weld literature and finding it was not as it seems, inspired me to do the same.

Over the last three years all I have done and continue to do is read from a variety of welding resources. So this past week I have focused my study on the "hands-on" practical aspect. It's amazing what you learn from having your nose in the arc rather than observing from out side the robot fence.

After reading your books and getting hands on experience, I now fully understand how and why Globular transfer is not a reliable mode of transfer, especially when utilizing it for high travel speeds (50- 70ipm). Tonight I was able to figure out how you were able to achieve over 70 ipm when welding in spray mode. I went snooping around the plant and found an old style of diffuser that was shorter than our common ones. I then took your advice from your Management Engineers book and cut about a quarter inch off the end of a contact tip. With having the tip well recessed in the nozzle, this allowed for a longer than normal wire stick out which decreased the weld amperage but still maintaining current within the spray range. The longer wire stick out permitted me to run higher WFS (higher deposition rates) without the extra amperage that would cause unwanted weld heat defects such as burn through or undercut. The weld spatter that resulted with the longer WSO was minimal and the spatter was easy to remove. Also the recessed tip and diffuser were spotless. After trying your ideas on attaining high deposition high speed welds in your "Management Engineers MIG book" it now makes sense. Thanks Ed for your extensive web site and your weld process expertise. Matt Finn. USA.

When asked for his opinion on spray transfer versus pulsed,
Albert might have said the following.



"Constant weld energy attainable from CV spray transfer
is a logical requirement for constant weld fusion".

 

[] Every weld shop that MIG welds should be aware that the primary weld concern with most steel and stainless welds over 3mm is to attain "sufficient weld fusion in a consistent manner"

[] A primary MIG concern with most steels under 2 mm is avoide weld burn through and distortion.

A common concern you will find with high deposition rate pulsed welds; When pulsed is used in the high, "stable spray transfer wire feed range", the pulsed arc influenced by the necessary high pulsed Hz and high peak current can depending on the pulsed equipment utilized provide an agitated pulsed arc that results in a narrow, high velocity plasma. This high velocity pulsed plasma can provide a digging effect resulting in crater problems and narrow weld penetration profiles that can lead to hot, center weld cracking.

Ed made this manual spray transfer weld with a $1700 traditional
MIG CV power source with an 0.045 (1.2 mm) E70S-3
MIG wire set at 450 ipm. 12-13 lb/hr.

IF YOU PAY $1700 FOR THIS POWER SOURCE.
WHAT'S THAT $12000 POWER SOURCE GOING TO ACHIEVE?

To attain the open arc spray transfer for carbon steel or common stainless steels, an argon mix is required along with a specific minimum amount of weld current (wire feed rate) and voltage for each electrode wire diameter selected. The resulting weld stream is protected from the atmosphere by the spray plasma, (the ionized, white, bell shaped cloud).

The spray transfer arc plasma not only conducts the weld current, the plasma with argon mixes also shrouds the electrode wire tip. In contrast, when using straight CO2, the arc plasma occurs "under the weld droplet being formed" supporting the weld drop as it gets bigger till eventually it drops off the wire tip in an erratic manner. This unique plasma LOCATION from the reactive CO2 gas is the reason you cannot get spray transfer from straight CO2, it's also the reason the CO2 content is limited to 20% in argon mixes. See MIG gas mixes if you want to cut through gas salesmanship and read more practical gas data.

 

Some one in the weld shop has to know the optimum
weld transfer mode that should be utilized

NO PLACE FOR SHORT CIRCUIT OR PULSED
WELDS ON THESE BOMB LUG WELDS:

In 2005 a major USA military contractor wanted to me to optimize the bomb lug welds that attached the cylinder shaped bombs to US air force planes. God help it if the bombs fell off the plane on its trip to kill someone. I was asked to review the weld processes available. The focus was optimize the vee prep weld fusion attained between the lugs and bombs, this was necessary as most of the bomb lug welds being produced had more than 50% lack of weld fusion.

To rectify this companies bomb weld issues I had my choice of any weld equipment, pulsed or spray . After I produced the pulsed and spray welds, the macro weld tests clearly indicated that the spray transfer mode had to be the first choice to provide the consistent weld fusion necessary.

 

From Ed's Robot MIG Process Controls Training Program

SPRAY TRANSFER & THE EFFECTS OF MILL SCALE:

The mill scale on that hot rolled plate surface to be MIG welded can be a poor electrical conductor causing arc instability. The electron conductivity of spray transfer is influenced by both the mill scale thickness and mill scale composition.


Mill scale acts as an insulator which can impede the electron flow from the cathode spots on the weld surface as they travel to the MIG wire tip. As mill scale increases in thickness the MIG weld voltage has to be increased and the weld will become more sluggish.

If you spray transfer on carbon steel without mill scale, and then without changing the weld parameters, spray weld on an application with mill scale, the welder would note the arc distance from the wire tip to the weld has reduced. The arc length reduction is a result of a decrease in electron conductivity, less electrons = less energy to melt tip of MIG wire so the wire gets closer to the weld. The shorter arc length often results in the MIG wire running into the weld, displacing the weld causing weld spatter. To reduce the weld spatter would require that the welder increase the weld voltage to increase the arc length. As we don't teach welders this simple fundamental fact we end up each day spending millions removing excess weld spatter.

As the mill scale has a higher melting temperature than the weld, the weld can be sluggish affecting the weld fusion potential and frequently the weld will solidify in a convex shape with a roll over at a fillet weld toe. The influence of mill scale and the process requirements to compensate for the sluggish welds and spatter control, is another reason why weld personnel would benefit from my weld process control training resources.

 

A WELD DECISION MAKER IS ONLY AS GOOD AS HIS OR HER WELD PROCESS EXPERTISE. IF YOU WANT IN-DEPTH WELD PROCESS KNOWLEDGE CONSIDER ED'S WELD BOOKS.

Spray and Pulsed MIG and Mill Scale.
Characteristics of a MIG arc that have influence mill scale.

An intense consistent high energy arc as found with spray transfer is more beneficial than pulsed (peak to back ground current) when dealing with mill scale issues. In contrast to pulsed MIG, the spray arc will;

[a] assist in maintaining consistent electron, and arc stability,
[b] assist in the consistent removal of surface contaminates,
[c] provide improved consistent wetting for a sluggish weld,
[d] provide consistent weld fusion.

Mill scale melts at a higher temperature than the base metal. Mill scale will cause sluggish solidifying welds. Fillet welds influenced by mill scale will often result in a convex, rollover appearance. The sluggish MIG welds made on heavy mill-scale parts will often result with unacceptable or marginal side wall weld fusion.

In contrast to pulsed, when using optimum spray transfer weld parameters with argon - 15 to 20% CO2, the spray plasma arc intensity is much more "constant" and the average energy generated is typically greater than that attained from the pulsed welds made in their optimum parameter range. With pulsed MIG, the plasma is influenced by the peak to low background current variations and the weld current and voltage fluctuations which are common from the electronic pulsed MIG equipment along with the low energy levels that can result from gas mixes like argon oxygen or argon 5 - 10 CO2.

 

Weld Voltage and Current Stability?

2004: While testing Japanese and Americam pulsed MIG equipment we had this oscilloscope graph made of a carbon steel "pulsed MIG weld" set at optimum weld parameters. The graph indicates, when using one of the most costly, popular and sophisticated pulsed MIG power sources sold in the USA, that weld current and voltage instability is the norm.

In contrast this graph below is regular spray transfer taken at
the same time from a CV MIG power source that cost 75% less than pulsed.

The MIG plasma shape: Spray transfer produces a bell shaped plasma. The wider the plasma in the cathode spots area, ( the work / weld surface), the greater the weld area that benefits from the MIG plasma surface cleaning attributes.

In contrast the pulsed process typically provides a narrow plasma that fluctuates with the change from peak to back ground current. As you increase the pulsed welding parameters to traditional high spray transfer wire feed (current) levels, when welding steels >5mm, the pulsed plasma zone influenced by the "high frequency, high peak pulsed weld current" can become intense. Typically the high frequency, high peak current can result in an intense pulsed plasma that's conical and narrow in shape. This narrow intense plasma configuration can cause an arc digging effect that can result in deep weld penetration and welds that may produce,

[a] narrow weld beads that produce (hot center weld cracks),
[b] undercut,
[c] crater cracks.



The MIG Arc Length and Robot Weld Speeds. The short arc length allowed by spray transfer can provide a highly localized, intense plasma configuration that is very beneficial on robot high speed steel welds, high deposition welds or when welding plate with surface contaminates such as mill scale.

< 2005: How many of you have used pulsed for high speed welds >30 ipm, and found the welds skipped. Just about every wheel or torque converter manufacture found this problem with their costly pulsed equipment, yet these manufactures continue to purchase pulsed weld equipment.

The pulsed mode requires for the uninterrupted formation and transfer of a pulsed weld drop per-pulse, a slightly longer arc length than traditional spray transfer. The bottom line, depending on the settings and equipment, the pulsed mode can be arc length (voltage) sensitive. In contrast, the traditional spray mode in which the metal transfers in a stream can utilize much shorter arc lengths and the continuous weld stream is hardly affected by arc length variations. This arc length is an important point as it affects;

[a] Shorter less sensitive arc lengths derived from spray transfer improve arc stability when welding at a high speeds.
[b] Shorter less sensitive arc lengths allows longer wire stick reduce wire burn backs to the contact tip.
[c] Shorter less sensitive arc lengths are beneficial when welding on mill scale or coated metals.

REMEMBER THE WELDING INDUSTRY WANTS YOU TO PURCHASE IT'S COSTLY PULSED MIG EQUIPMENT IRRESPECTIVE OF THE WELD APPLICATION. THIS SITE FOCUSES ON OPTIMUM COST EFFECTIVE WELD MODE / CONSUMABLE SELECTION AND PROCESS OPTIMIZATION TO SPECIFIC APPLICATIONS, THICKNESS OR WELD TYPES.

MIG Gas Notes for Mill Scale: When spray transfer welding on troublesome mill scale applications, a high energy MIG gas mix such as argon with 15 to 20% CO2 is recommended. The 15 to 20% CO2 gas mix in contrast to a lower CO2 mix, or argon oxygen mix, enables higher weld voltage and promotes higher energy at the cathode locations on the plate or weld surface.

The higher CO2 weld voltages combined with the molecular arc dissociation properties of CO2, improves the electron flow, improving arc stability. This additional energy improves the weld fusion and weld wetting. An additional benefit also is less weld porosity potential. What makes CO2 gas unique? The CO2 plasma provides unique "gas dissociation properties". In the MIG arc, the CO2 molecules break down from CO2 to CO and O2. When close to the cooler weld surface the
CO - O2 molecules form back to CO2. The gas dissociation, "molecular change" adds energy to the weld. Also in contrast to oxygen, the CO2 gas requires higher weld voltages.

For those companies that use argon oxygen mixes, or the heavily marketed, useless three part mixes containing argon - CO2 - oxygen on CARBON steel applications that have mill scale, (applications >3/16), they should realize they are jeopardizing the weld fusion potential and increasing weld porosity potential.


The oxygen and low CO2 in the argon tri-mix results in a spray transfer plasma in which low to medium weld energy is generated in the outer periphery of the plasma. This results in finger weld penetration. As the narrow finger solidifies rapidly this increases the opportunity for weld porosity to form especially in the finger shaped weld root. It's very common for this to show up in ultrasonic evaluation or x-rays on fillet welds on parts > 5mm.

In contrast to what your weld gas sales rep tells you, two or three component gas mixes containing oxygen can result in welds with greater potential to create;
[a] weld porosity,
[b] welds with lower weld energy, resulting in inferior weld fusion profiles,
[c] less gas in the cylinders than that attained with argon 15 - 20% CO2 mixes.

For extensive weld gas data see the weld gas section or better still invest a few dollars on yourself and purchase one of my welding books. One of my books "A Management Engineers Guide TO MIG" has over 600 pages on how to control the MIG and flux cored process.

Note: ED WAS A KEY WRITER OF THE AWS "MIG GAS SPECIFICATIONS".
A SPECIFICATION THAT CONTAINS A FEW REAL WELD FACTS;

E Mail. July 05.

Ed. It looks like we are just starting out on a new Chrysler project welding a galvannealed product, Galvanneal NS 6000 D series 44a. According to the Chrysler spec, we would be allowed to use a solid carbon steel ER 70S-3 MIG wire, but they require a 75 argon / 25 CO2 gas mixture for this. I think Chrysler takes the cake on this gas selection. By the way if our engineers had selected galvanized material, according to the Chrysler spec we would have been forced into using the terrible self shielded FCAW process.....Is the Chrysler weld engineer from this planet? What I also don't understand is the fact that they are specifying a coated material, and then we are still required to e-coat the part. I wonder what the reasoning is behind double coating the cradles.....I'm sure they don't even know.

Regards GR. Tier One.

Ed's Answer:

There is no rationalization for most of the weld logic that comes from the mouth of Corporate Chrysler. Their chief welding engineer has for more than a decade been in the wrong profession. The choice of the 75-25CO2 gas restricts the use of spray transfer on robot welded parts over 0.070, this gas will be the cause of weld spatter or weld burn through. As for the use of the self shielded wire, no one knows why the Chrysler corporate engineer still insists on the world's worst electrode for coated materials. As for the double coating, it makes no sense. What does make sense is to coat the parts after welding as irrespective of the coating type, the weld destroys the coating in the weld area. As I have said on numerous occasions on this site don't look for weld reality when dealing with Chrysler look for Chrysler to be out of buisness during the next decade.

Want to know how to reduce cracks or arc blow.

Minimum Spray Transfer weld current with argon > 10% CO2 Mixes.

Many welders and robot programmers are not aware of the minimum weld current or minimum wire feed rates necessary to attain optimum spray transfer. Its therefore not surprising to frequently find welders or robots welding with globular transfer and creating a weld spatter mess.

When welding carbon steels with the 0.035 (1 mm) wire, and a 15 to 20 CO2 mix, to achieve spray transfer, a minimum weld current of >180 amps is desired.

For the 0.045 (1.2mm) wire and the 15 to 20 CO2 mix. To achieve spray transfer, a weld current approximately
>250 amps is desired.

These minimum spray transfer weld current settings are reduced with lower CO2 mixes,
or when those useless two or three component argon mixes containing oxygen mixes are used.

There is an optimum MIG Wire Diameter for every application thickness.

As I have mentioned 600 times, the auto / truck industry is one industry that for decades has been notorious in it's selection of unsuited MIG and flux cored electrode diameters for welding steel applications < 6mm and few companies understand the weld wire, weld mode, weld current, weld size and "weld part thickness relationships. For those individuals that want to proffesionally manage weld processes, this is an extensive part of my books and weld process control training programs.


2010: Did you ever consider why, after nearly 50 years of making MIG welding equipment and welding consumables, that Lincoln, ESAB (Linde), Miller or Hobart did not put practical MIG weld parameter information on their MIG wire packages or along side the relevant MIG wire feed or power source parameter controls?

I believe the reasons the MIG welding electrode wire manufacturers never provided their welding customers with practical, cost effective MIG or flux cored welding data on the wire boxes, is because they did not employ management or engineer that had figured out the simple relationship between the few required wire feed and voltage settings necessary for the majority of all the common global MIG and flux cored applications.

In the weld equipment and consumable supply companies, marketing and real world data were often far apart. The incredible lack of weld process expertise that prevailed from most of the world's largest weld consumable manufacturers is not that unusual. As we all are aware just because you make something does not necessarily mean you are an expert in it's use. The sad issue today for the self taught global weld industry, after 50 years of weld misinformation, too many weld shop still rely on these same companies for weld advice.

Note: In the 1980s in a marketing program I set up at AGA in Cleveland. We introduced weld wire from S. America and on the MIG wire boxes I had printed all the short circuit and spray weld settings for 0.035 and 0.045 wires

Many manufacturing companies are under the impression that because welding equipment and consumable manufactures have expertise in making welding products, these same companies are also experts in the use of those products.

GM make cars, but it takes a specialist race car driver to win a race with that car. By the way, I would like to thank the corvette racing team for making me there unpaid MIG weld consultant.

Note: Ed GOT THE GM MANAGEMENT / ENGINEERS TO STOP USING THE NASTY LINCOLN SELF SHIELDED FLUX CORED WIRES ON THE CORVETTE BODY AND TRAINED THEM HOW TO USE MIG SO I SUPPOSE THERE IS HOPE.

The MIG process celebrates 50 years as being the worlds most important weld joining process yet, how many of you have watched weld equipment and consumable reps "play with the weld parameter controls" during a demonstration of their companies MIG equipment, weld wires, gas mixes or E71T-1 flux cored consumables?


For an experience you may not enjoy. Next time you visit a Fabtech or AWS weld show, ask the Lincoln - Miller - ESAB - Panasonic rep the following technical question. Look for someone demonstrating pulsed MIG, then ask them to do a 6 mm vertical up, carbon steel or stainless fillet weld on > 1/4 (6mm) plate. After the weld look the rep in the eye and ask how his pulsed wire feed rate compares weld deposition wise with an 0.045 (1.2 mm) E71T-1 wire set at a feed rate of 400 in./min. The weld you view and the answers you receive to this fundamental simple weld question will show you how little or how much is known by the so called weld equipment / consumable experts.

Before weld personnel provide an opinion on a welding process or weld consumable, they should have all the facts on the processes and consumables that compete with their process or consumables. And of course if they were a true professional they would then provide an answer without product or process bias.

< 2005: The sales reps promoting pulsed weld equipment at the AWS or Fabtech trade shows may extol the virtues of their weld equipment benefits, however, the bottom line is those benefits may dwindle quickly when you take a real look at the poor and inconsistent arc characteristics and then provide a realistic comparison of their process or equipment against other processes, mode of weld transfers, equipment and consumables.
tes the welding industry.

< 2001: When Ed set the robot welds for the new, more robust Harley bike frames, he resisted the use of the pulsed mode and used spray transfer. Ed set 3 simple weld schedules for the more than 50 welds required on the frames.

Note: At the main Harley Bike plant, I sat in on a meeting in which two weld engineers and nine robot personnel discussed for more than two hours a robot MIG weld spatter problem on a bike gas tank. At the end of two hours, the problem was unresolved. Thanks to the Harley hands off management approach, I was not allowed to speak at this meeting. For me it was a sad engineering situation, as this American company with its global reputaion indicated that it's combined mangement and engineering resources could not resolve a simple weld issue that should have taken two minutes to resolve.

HOW MANY PRODUCTION MAN HOURS ARE LOST EACH YEAR TO WELD TEAM DISCUSSIONS ON ROBOT WELD ISSUES THAT WITH A LITTLE PROCESS EXPERTISE COULD BE RESOLVED IN A FEW MINUTES? Ed Craig. 1985.

 

If you want a quick evaluation of the weld process expertise in your shop, ask three of your welders or the weld shop supervisor to tell you the 0.045 (1.2mm) wire feed position in which the start point occurs for spray transfer, you may be surprised at the diverse incorrect answers provided for the world's most popular wire size and the worlds most utilized weld transfer mode.

If you think your weld personnel fully understand the weld process they make a living from, why not give them my MIG weld process control quiz?

 

 

"PLAY AROUND" NO MANAGER OR ENGINEER SHOULD ALLOW THESE TWO WORDS TO BE USED FOR THE MANUFACTURING PROCESSES CRITICAL TO THEIR ORGANIZATION?

The good news is the common lack of MIG and flux cored weld process expertise can be quickly eradicated. First managers have to put their focus on the root causes of their weld issues and always remember that product liability starts in the front office, not on the factory floor.

Click here for information on Ed's books and training resources.

Throughout the weld manufacturing industry, "purchasing" or other inexperienced personnel are frequently involved in weld consumable and weld equipment selection decisions.

Perhaps your company has the following purchasing mind set in which the purchasing manager has found out that "bigger weld wires which cost less than smaller wires can result in a "weld wire cost reduction"

With MIG or flux cored consumables, bigger wires (less drawing) typically cost less. Unfortunately too many weld companies have managers that think reducing the cost of the welding consumable is the key to weld cost reduction, (see weld costs).

When selecting the correct MIG wire diameter, the optimum weld current compatibility of that wire with the part thickness, the weld transfer mode and weld size are the prime considerations for consumable selection. Selecting the optimum MIG wire diameter requires MIG weld process expertise. For those companies that are utilizing wire diameters that are too large, most will be in the globular mode the weld cost and weld repair consequences will be extensive.

It's a fact that the majority of MIG and flux cored robot applications welded in the North American auto / truck industries are using weld consumable sizes that are not optimum for the welding applications.

To Ed Craig. Sept 2004.
E-Mail Question.

Question: Ed our company is a US based, Japanese auto parts manufacturer. We use Japanese robots to MIG weld 0.035 to weld 0.100 steel parts. The company uses the pulsed MIG process, argon gas mixes, and 0.045-in weld wire. We use Japanese MIG wires equivalent to AWS E70S-6. The manager wants to reduce robot-welding costs. I am currently writing a cost justification calling for a change to a MIG wire manufactured in North America -- possibly an 0.035-in. wire. The company engineers, however, insist on sticking with the imported Japanese MIG wire which costs approximately $0.50 more per pound than equivalent domestic MIG wires. These engineers also inform me I cannot change the wire size or type since the code states this wire is an essential weld variable. Am I correct that according to most codes, as long as both wires are E70S-6s, they are interchangeable and therefore a nonessential weld variable?

Ed's Answer:

Essential weld variables are three words that may carry some weight in an organization that welds within the boundaries of codes such as API or ASME. However from a common sense perspective these three words should never be used within the boundaries of an automotive plant.

First, irrespective of the codes or weld procedures in place, as long as the plant uses argon mixes there will be no negligible influence on steel weld mechanical properties, whether the MIG wire is American or Japanese E70S-3 or E70S-6. Both these MIG wires are qualified for argon mix use. Second, if the company changes the wire size, it's logical to redo the weld procedure.

Importing costly MIG wires into the USA a country that has the world's largest MIG wire manufacturer makes as much sense as exporting USA coal to Newcastle UK. Any US or Japanese auto-manufacturing company that throws money out the window by importing expensive Asian MIG weld wires needs a new plant and engineering manager.

It makes little sense to be concerned about so-called essential weld variables when the pulsed-equipment manufacturers are making radical E –Prom changes to their weld equipment every few months. Each robot line brought into a plant has pulsed equipment that may have little in common with the pulsed-weld equipment purchased two years ago.

Weld procedures have little meaning when the weld equipment used is either changing or inconsistent. In fact, that's the best way to describe pulsed process, forever changing and rarely constant. It also makes little sense to worry about essential weld variables, when every day some robot technician is probably making unqualified weld changes to the robot data. And most important why worry about essential weld variables when the parts produced will likely suffer from dimensional instability.

It's getting rare in auto truck manufacturing plants that strive for manufacturing autonomy to see effective weld practices or effective robot weld process controls implemented. It's even rarer to find engineers in this industry who have in-depth weld process control expertise. This of course leads to many weld consumable cost distractions and if you had personnel qualified to provide real world opportunities for weld-cost reductions.

To have an impact on a plant's weld costs forget about saving pennies on consumables and start out with an evaluation of the “weld deposition rate potential” and the real-world weld efficiency of the robots. Evaluate the robot's downtime and the weld rework generated. Compare these numbers with the information attained in my robot-weld-process-control book. Check out the high weld-speed benefits of a 0.035 or 0.040 in. wire on parts less than 0.080 in.

The engineers, who want you to use the Japanese weld wire do so because it's the wire they are familiar with. When engineer's lack weld process depth, it's logical for them to fear a process change, and my solution to that would be to fire all the engineers and managers involved.

 

1998. The best MIG weld wire for the auto and truck
industry is of course the one they rarely will use.

Weld Question: We use an 0.045 wire. What's the best MIG electrode "size" for a carbon steel or stainless spray transfer robot applications? Our key weld requirements are;

[A] MEET A MINIMUM THROAT DEPTH ON < 5 mm PARTS.
[B] GOOD SIDE WALL WELD FUSION
[C] WELD SPEEDS ABOVE 40 ipm

Answer: Considering the weld current compatibility with the part thickness and desired weld size, the following is a logical choice of MIG wire size selection.

[a] Robot / Manual spray welds on steel / stainless parts < 5 mm.

If available, the first choice MIG wire diameter would be the 0.040 (1.1mm) MIG electrode wire.

If the 040 wire is not available, use the 035 (1mm) wire. Wires smaller than 0.045 provide superior small weld puddle control and the spray current range of these wires is better suited to the thin metals < 5 mm.

E-mail March 2007.
Ryan Good. Dana.

Hey Ed:
Just thought I would drop you a line and let you know that in the beginning of April, thanks to your advice, we will be working on switching over the 5th Dana plant to an 0.040 MIG wire and using the spray transfer mode instead of 0.052 globular mode we were getting with the Rapid Arc (Lincoln's pulse program). Thanks Ryan.

 

High spray weld current >400 amps can cause excess weld fluidity creating a challenge for a manual welder, especially when producing horizontal fillet welds larger than a 1/4 >6mm.

A horizontal 5/16 (8 mm) fillet weld provides a welding challenge. Maintaining weld puddle control, avoiding undercut, and at the same time ensuring consistent side wall weld fusion are three of the prime reasons the 5/16 (8 mm) fillet weld is usually the maximum horizontal fillet weld size allowed. This is also why robots should when possible weld large fillets in the flat position.

When welding in flat positions rather than the horizontal position, and the parts are >5/16 (>6.5 mm), an 0.052 (1.4mm) MIG wire is beneficial and this wire will cost less than the 0.045.

Lets see, the electrode size recommendations should provide an optimum spray transfer current range which is compatible with the part thickness and in particular the fillet weld fluidity requirements.

This is an interesting approach to weld wire selection and weld process control. Weld current compatibility with the part thickness means the electrode selected can use the high end of it's optimum operating parameters without concern for an agitated arc plasma and a turbulent weld puddle. Using the right current , means no concern for over heated, oxidized welds or weld burn through issues. High welding parameters allow high wire feed rates resulting in optimum weld deposition rates and maximum weld travel rates for the weld consumable utilized.

Weld Current Compatibility with the Part Thickness.

Extensive written data has been provided on the subject of SMAW (stick welding) reference, electrode diameters, weld current and part thickness requirements. In my books, I focus on this subject for the MIG process and I have written more on this subject than any other global welding source. The selection of the correct GMAW electrode diameter is an essential consideration for attaining both optimum, robot / manual weld quality and productivity.

 

< 2004: E-Mail from Shawn.

Question: Ed on our robot application we have a multi-process pulsed / short circuit / spray power source. We weld auto thin gage steel parts from 1 to 4 mm with 0,035 wire. Is there a defining line when we should switch from one mode to another?

Answer: Shawn really good question.

For robot applications < 0.070 I would use short circuit before pulsed. The SHORT CIRCUIT mode is an arc on / arc off weld transfer and therefore provides less potential for weld burn through, especially if weld gaps are involved.

For applications 0.070 to 0.150 pulsed fits the bill and will typically allow the use of higher wire feed rates than short circuit, however if gaps greater than 0.060 occur remember short circuit. .

Robot welding >0.150, take your choice of spray or pulsed If using spray with an 0.035 wire and the welds are is too hot consider with pulsed, an 0.045 wire and argon 10 CO2.

With MIG weld wire selection for spray applications, big is rarely better.

Neither manual welders gloves, or the weld equipment used have an infinity for spray transfer when the weld current used is above >380 amps.

The optimum spray current that provides ideal weld puddle control with the 0.045 MIG wire is typically found between 250 and 380 amps. Welders do not like the weld heat generated from spray once the weld current passes 360 amps as required with both the 0.052 (1.4mm) and 0.062 (1.6mm) wires.

Often when using the large diameter wires, and this applies also to >0.062 and larger flux cored wires, you will find that too keep the manual weld heat at a comfortable welding level, the welder will set the large wires at a "low wire feed setting". Few weld supervisors check the wire feed settings, and even fewer understand the potential weld deposition rates / weld costs that can be attained. Lets face it we all know that weld deposition rates are not a daily topic of conversation for most weld shops.

The bottom line, the large wires typically produce more weld smoke and lower weld deposition rates than they would have attained with the more manageable, smaller 0.045 MIG wires.

I hope you are not still taking notes. Invest in yourself and consider one of my books. This robot / manual MIG self teaching process control book is available in both English and Spanish. The book has 170 pages with 170 MIG questions all directed at weld process control and weld parameter selection simplification.

For your weld shop training needs this self teaching training book along with the video which is half price with a book order will be the most practical weld data resource your welding personnel will ever attain. Welders, robot programmers, robot operators, QA personnel, weld supervisors, managers and engineers all will benefit from this valuable weld process resource.

To get all manual welders and robot personnel to "one weld mind set" use the MIG training book and my unique MIG training CD process control program and video. Click here for info.

Keep Smiling:

You can pulsed MIG, use spray or regular TIG when welding
Titanium but you will get the best weld results with TIP TIG.

TRADITIONAL ORBITAL TIG ON GRADE 2 TITANIUM	MANUAL TIP TIG ON GRADE 2 TITANIUM
While using the slow manual or automated TIG process, there is always concern about excess weld heat and the oxidation effects on Titanium alloys. Typically manual or mechanized titanium TIG welds on parts over 3 mm will be carried at weld speeds in the 3 to 5 inch/min range. To potect those low speed high heat welds, cumbersom trailing shields have been a critical weld requiremento minimize the effects of oxidation. When welds are subject to oxidation you know weld porosity has to be an issue. The high TIP TIG weld speeds and weld TIP TIG weld agitation will produce the cleanest possible titanium welds.	With either the manual or automated TIP TIG process, TIP TIG titanium weld speeds will be much faster. Typically 10 - 30 inch/min. The higher weld speeds enable the TIP TIG welds on on some titanium > 5 mm applications to produce silver welds without the use of a trailing shield. If your organization uses regular TIG on Titanium, you will be pleased to know that with TIP TIG, those manual or automated titanium welds can typically be carried at 100 to 700% faster weld speeds with superior weld quality. Visit TIP TIG

Continue with Spray Transfer Part 2

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expertise visit www.weldreality.com



For TIP TIG better quality than TIG and
up to 10 x as fasf visit www.tiptigusa.com