Dual shield is a very fast process:cool2:. Time is money!

 

Flux core-gas (dual shield) runs well in all positions (unlike solid wire mig). Dual shield has superior penetration over solid wire with gas. Dual shield runs clean and spatter free, unlike flux cor self shielded wire. Dual shield has very high rate of metal deposition and is the preferred wire for large structural steel welding projects. You can run dual shield outside, you just need a wind shelter.

 

You can run dual shield outside, you just need a wind shelter.

We ran dual shield, splicing these 10-feet diameter X 1-inch wall piling in the Columbia River gorge.

 

So, it's faster and smoother. May I ask, how come it's faster????
Thanks,
Pete

 

faster.... refer to deposition rate (lbs of metal per hour deposited) hardwire 045 can be about 5.4 lbs/hr while ultracore 045 can be 11.9 lbs/hr (also notice melt of vs deposition rate)

ultracore> lincolns brand of 'dualshield' its what i use

for referance;
http://www.lincolnelectric.com/asse...ets/global/Products/Consumable_MIGGMAWWires-SuperArc-SuperArcL-56-N/c101011.pdf

http://www.lincolnelectric.com/asse.../Consumable_Flux-CoredWires-Gas-Shielded-UltraCore-UltraCore71A75Dual/c3128.pdf

 

Its more commonly used on larger machines, and structures. It runs hotter and faster, and smoother than solid wire. It takes about 25v and 450 ipm to run just .035" dual shield/outershield. .045", 1/16" and up are fairly common sizes. It gets better penetration, is more tolerant of contamination than solid wire mig, and doesn't smoke as bad as gasless flux core. The slag peels off easily like 7014/7018 . Next time your near a back hoe, excavator or forktruck, look at the larger welds. You'll notice the welds are really smooth, almost ripple-less. They are most likely dual shield. In a nutshell it works, try a spool next time you have a lot of Heavy section I-beam splices, or heavy wall structural tube frames. My lincoln 210 mp can really only run the .035 well. "Willie" has a thread in another part of this site stating that he finally "gets it" .It might bring more light on the subject for you. I think a lot of Hobbyists use it in 33lb reels. Lincoln calls their brand Innershield, and I think Esab calls their brand Dual Shield. Put on your heavy gloves and buy some extra tips if you buy a roll.

 

MIG covers a lot of territory. Dual Shield is faster than short circuit MIG because you run hotter and with higher wire speed.

I don't know how dual shield compares to pulse and spray MIG, seems like solid wire would be faster than tubular.

We run short circuit roots and fill and cap with dual shield on the smaller pipe up to about 12 inch where I work. Not sure why we don't use pulse, a lot of shops are doing it.

 

MIG covers a lot of territory. Dual Shield is faster than short circuit MIG because you run hotter and with higher wire speed.

I don't know how dual shield compares to pulse and spray MIG, seems like solid wire would be faster than tubular.

can be faster, cheaper, and more cost effective. such as in flat horizontal spray. but not by much. dual shield does it all, and is easily and consistently certifiable. therefore it is the process of choice for most construction and industrial operations.

the main reason i choose dual sheild for 90% of everything i do is consistency and speed. i very often lay down 15lbs of wire in a day, sometimes as much as 25lbs. and thats only in the 045 flavor. and it is always a good, deep, clean weld. if its not a good weld i can tell visually, i've been tricked with hardwire, it can look good but have nearly zero penetration. my 2cents

 

Dual shield, if I'm not mistaken, has a higher tensile strength than hard wire. I've always equated dual shield to 7018 and hard wire to 6011/6010.

 

it is a common misconception and commonly referenced by those in the industry that "dual shield is stronger than hard wire". It is complete misinformation as there are too many variables to consider and no definition in that statement of what is meant by 'stronger'.

one of the more common FCAW-G wires is E71T-1 which has 70 KSI MINIMUM tensile strength. the same is true for all ER70S-x wires. 70 KSI Minimum Tensile strength across the board.

FCAW-G can put down more lbs per hour for a number of reasons including and not limited to increased voltages and speeds due to two shielding mechanisms as opposed to relying only on one as with GMAW. FCAW, with its tubular structure, and by its very nature of having a flux, can be tailored very specifically to the job at hand by adding alloying elements or de-oxidizers in varying ratios with minimal reset at the manufacturing facility. Adding iron powder to the flux, in addition to many other elements, can also increase your deposition rates allowing a welder to put down significant amounts of weld per hour.

Consistency and the necessary high voltages and amperage as compared to hard wire GMAW also allows the wire to forego the common missteps of cold lap and lack of fusion making it more trusted and more easily qualified to different codes.

 

I believe our hard wire is 70s6, so should be pretty close to the same tensile strength.

 

both hardwire and dualshield have same tensile

*generally speaking. can be had different

 

For flat position flux free hot welds I prefer metal cor wire. For out of position welds, dual shield is the way to go.

 

I seldom worry about weld metal tensile strength. 70,000 is almost always enough. Fusion, and ductility are more important in my mind. A 100,000 LB tensile weld metal is of no advantage if it didn't adequately fuse with the steel being welded, or if while cooling, (shrinking) it pulls away from the workpiece 'cause it can't stretch.

6010 gives me the best penetration, and therefore fusion, it stretches easily maintaining strength until cool. Its shortcomings (in my mind) are; it doesn't run uphill super easy, and the water, and hydrocarbon flux give it lots of hydrogen molecules that migrate to the perimeter of the molten steel. This phenomenon might leave an opportunity to crack. I'll get flamed for this statement, I admit I've never had a good 6010 weld break, but I tend to be over cautious.

Dual shield is fast, but that's not my concern. It gives good penetration, without much hydrogen. It runs uphill incredibly well, and has enough ductility to still be strong after it shrinks.

The phenomenon of overheating the gun, while the welding machine doesn't seem to overheat, I don't yet have an explanation. It is spray transfer, so the arc is on all the time, there is jetting action, where solid MIG usually doesn't.

Willie

 

Well, I may say I got a lot of information out of you guys, and good info, too. I'm sure you helped a lot of others wondering what I was. Since I'm only a small repair guy, that hasn't seen even 1/2 inch steel to weld, I'm hoping my setup of a portable 110v flux core machine for on the job fix its, another 110v mig machine for smaller gas mig, an alpha tig for other stuff, and my 220 amp machine with spool gun for bigger stuff.
Thanks again for the help,
Pete

 

The dual shield also aids the not-so-good-relationship between hard wired+gas and evul mill scale,especially on material over 3/8.
That said I'm still a 7018 guy but "production" in my world is only 6-8 columns or repairing a machine.I wish it had existed back in the day when an order for 80-100 columns wasn't unusual. My back doesn't miss it tho.

 

"Back in the day" gotta be a long time ago. Dual shield has been around since the seventies. :drinkup:

 

Quick question on Dual shield. How do u think it would run in the Miller 350p in pulse mode?

 

Good question. I've never tried (or seen / heard of) dual shield being run in pulsed spray mode. But though because of the slag it doesn't sound like all that good of idea to me. But I don't know for sure whether or not that's a deal breaker or if there's any advantages to be gained from running it pulsed.

Metal cored wire on the other hand does run good in pulsed spray mode. In fact you pretty much have to run it in pulsed mode if you're going to be using it in any thing other than flat or horizontal.

If I had a 350p I don't think I'd be able to resist the urge to try running some metal core wire in pulsed mode with it. That might be some thing that could serve you real well for a lot of things.

 

This is a very informative thread. Many thanks to the pro's for sharing their knowledge.

 

I agree - I had heard great things about Dual Shield and came on here to learn a few things - man - what a wealth of knowledge you guys have shared here - Thanks so much !

 

when the erecting contractor is paying upwards of 100.00 bucks an hour per highly skilled welder he wants as much high quality weld metal as he can get. column splices and heavy moment plates can be knocked out in no time with this process.

 

IN your world.
We didnt "discover' mixes until the middle to late eighties. Dual shield was Trojan and a Colt 45 in case her husband got home early............

 

Isn't dual shield a little more forgiving than solid wire on rusty/dirty metal, in the same way that 6010/11 is more forgiving than 7018? (I'm not a MIG guy, but I got that feeling the one or two times I used it.)

 

I'll bet he does Dick.
Jerry

 

What about the polarity of dual shield? EP? Like SMAW?

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

yes, DC+

 

Something that people are missing is that dual shield historically had best charpy impact test values. From what I understand it still has. It isn't important until you are involved in structures that have sudden loads at low temperatures. I know that in Canada this was a big deal and years later this caught on in California for that extra earthquake protection. Things given an steady load were fine but give them an impact load like an earthquake and welds fracture. The charpy is expressed in foot pounds at different temps. The machine to test is a big sledge hammer on a hinge like a clock pendulum. You chill the sample to the required temp then quickly clamp it in the vice at the bottom and release the hammer.

 

From what I was told years ago, Dual Shield was originally designed to be a replacement for SMAW to reduce waste (stubs) and starts/stops. But factor in the cost of gas, machines, and the lack of portability, it's not a cost effective replacement. SMAW still has it's purpose. But I'll use Dual Shield over SMAW any chance I get. Probably because I haven't done SMAW in many years, and if I were to give it a whirl today, it would probably look like bird ****.

 

I would respectfully disagree. With the availability of suitcases and a hundred feet of gas hose it is just as portable as a SMAW setup. Add into that the fact that you arent paying a welder to stop every 8-10" and you are well ahead of the game.

FCAW-G is miles ahead of SMAW in deposition rates as well.

A you stated, SMAW still has its place and i do agree with that. SMAW will not be going anywhere anytime soon. There will never be a "one process for all" that eliminates the other manual processes for good.

 

What gas or mixture do you run with DS?

 

I've always used tri-mix on jobsites.

 

I've always ran either 75/25 or 100% co2 with dual shield.

 

I've ran some dualshield at a shop a worked at a while back and I don't remember ever grinding mill scale.
My question is, Now that I'm running my own shop, if I have a staircase to build (or some beam work) can I get away with welding right through the millsacale? That would save me a TON of time on some jobs instead of grinding the mill scale and mig welding.

 

Sure, I don't grind millscale when using hard wire, certainly not with mill scale.

 

The thicker the plate the more heat you need. Steel melts around 2800 deg. The temperature of a flux core weld puddle is between 5000-7000 degrees depending on the setup. More than enough heat to melt the base metals.
The weld is usually stronger than the base metals.