45 cfh seems awful hi for the gas. If I remember right I think I only run 20 to 25. To much gas will create a turbulance and not be as effective.

 

Lanse try putting that roll of wire in the oven over night. I'll bet it picked up some moisture!

 

What polarity is used for FCAW gas? I know FCAW is straight and MIG is reverse polarity but FCAW gas, I dont know.

 

Far as I can remember FCAW-G is DC+, but not all FCAW-S is DC-! You really need to read the manufacturer's spec sheet. A lot of FCAW-G requires different amounts of cfh of gas. Some will only run on 100% Co2.

 

Thats good to know CEP. Thanks, I will keep it in mind to read the specs.

One question tho, I thought the G was for position . Am I confused or is FCAW an all position wire? Also, is LANSES's gas to hi at 45cfh?

 

G stands for gas shielded. S stands for self shielded.
Far as I know all FCAW-G is all position. There are several FCAW-S that are flat only.
You have to read the manufacturer's spec sheet. Every wire is different. And generally when they suggest the amount of stick out, they're not kidding either!

 

45 cfh may or may not be too high. Higher voltage needs more gas. Moisture, excessive voltage or wrong stick out are the most likely cause. Some wires are co2 only , some are c-25 only and some work with either one. The wire manufacturer should have gas suggestions and parameters.

 

The voltage you are running determines the arc length. The stick-out determines how hot the wire gets before it reaches the arc. If there is a condition resulting where the flux is broken down before it reaches the puddle, it will have porosity. I see this all the time in my shop and it makes pull my hair out. A guy will weld it, say it went in good, but have worm tracks and have no idea what it is, and blame everything but himself. It is almost always too long of an arc. Why? Because a nice long spray cone looks, and sounds good. Well its not SMAW, and if its not self peeling its not a good pass FCAW-G. Period. Go back to short circuit and work your way up. Lincoln really does not have any tolerance for heat.

 

I have had problems with gas shielded flux core as well. Just the other week I was welding a flange to a pipe on a positioner. I got the inside welded, back gouged root pass next pass then my next fill pass no matter what was swiss cheese. Checked everything, had an old timer come over and look and see if he could see anything. I gouged that weld out 3 or 4 times maybe 5. (it was a rough day, The piece was supposed to be for a cert. as well, thankfully I passed) I finally got it welded out, never had any idea what caused the porosity.

 

42 CFH is about right for most .045 -1/16" gas shielded flux core wires. I would say your wire picked up moisture. Its technically a low hydrogen electrode and susceptible to moisture pickup from the air. Id put it in an oven for a couple hours at 450 if its on a steel spool. Plastic spool prob means its junk

 

Lanse, I've done Flux core for quite a few years and what your describing we call Worm Holes as opposed to porosity mainly because these holes tend to spiral around inside the fillet before breaking out. One of the causes i tend to find out is that the metal needs to be spotless and where you say your gas is set to 45 cfh try setting it at 25 - 35 in stages and see how you got on.

This is beacuase excessive gas flow does causes weld surface turbulence. This porosity can result with gas flow greater than 40 cuft/hr. Optimum MIG and flux cored gas flow for carbon steels is 25 to 35 cuft / hr. The shielding gas flow should be measured as it exits the gun nozzle, so use a Gas Funnel Meter

Let us know how you got on :waving::waving:

 

I've found that my stickout has the greatest impact when welding with FCAW-G. Even on the cleanest metal, I can create wormholes if my stickout is less than .75" or greater than 1". I have no problem welding steel with the mill scale on in any position if I mind my stickout. I run 40 cfh C25.

 

I'll also add that I only run .045 Outershield. I can't say what my stickout for other wire diameters would be.

 

CEP

Just a sidebar to clarify one point; there are gas shielded fluxcore wires that are for flat and horizontal only. Look at the AWS classification on the box

E71T the 1 indicates ok for all positions
E70T The 0 means only good for flat/horizontal

E71T-1C All position; and the C is for 100% CO2 shielding gas
E71T-1M All position; and the M means mixed Ar/CO2 shielding gas(typically 75/25 Ar/CO2)

Typically E70 class wires for flat and horizontal have much higher deposition rates than wires with all position capability. Here's an example

http://www.hobartbrothers.com/product-details.html?name=FabCO®+11

Its an E70T-1C wire; 3/32" diameter, flat and horizontal only, using 100%CO2 gas. 35Volts 600amps 23 lbs per hour deposition rate. Not for the faint of heart.

 

CEP

Just a sidebar to clarify one point; there are gas shielded fluxcore wires that are for flat and horizontal only. Look at the AWS classification on the box

E71T the 1 indicates ok for all positions
E70T The 0 means only good for flat/horizontal

E71T-1C All position; and the C is for 100% CO2 shielding gas
E71T-1M All position; and the M means mixed Ar/CO2 shielding gas(typically 75/25 Ar/CO2)

I did not know that! See learn something new here just about everyday!
Thank you!

 

To the OP's original question:

Lanse, correct me if I'm wrong, but I think it gets pretty humid in Austin, TX in the summer? My vote is for moisture pickup as the root cause of your problem. Check Lincoln's website to see if they reccomend baking that wire you have. If they don't say one way or the other, you can try baking it for a few hours at 225-250F. No guarantees this will work, but at this point it doesn't hurt to try. You don't want to burn off the lube on the surface of the wire, so keep the temp as close to 225F as you can. If the wire is rusty, I'd cut off and discard the outer layers. Throw away anything that's red/brown.

Second thing to do is throw a spool of solid wire in the machine and see if the porosity problem persists. If so, then you've got a gas leak somewhere, and your fluxcored wire my not be the source of the problem. If the machine welds solid wire ok then you can guarantee that the fluxcored wire is the source of the porosity.

 

When I first encountered dual shield flux-core, I thought it was great. I got complimented first thing on my second day and that was the first time I ever used it. That changed when myself as well as other's in the shop discovered that it will screw up and have porosity for no apparent reason. One guy was so pizzed, he took the gun off the machine and threw it across the shop. We were welding flare stacks that had a base plate with 4 gussets on the bottom. They were set up on roller stands. You could weld out 3/4 of them perfect and the last 1/4 you'd get porosity. It was a real pain having to take a die grinder to grind the welds out and if you didn't get all the porosity out, it would come back in your next attempt. I've heard if the nozzle gets too hot will cause this but who knows?

I was applying for another job using metal-core that I'd never used. I talked to guy that ran a private welder training and test center and he gave me some pointers as to where to set the machine. The shop said I could go by and try it out before I had to do the CWB test the next day. Once I figured out you push it like MIG, it ran real nice. Then the foreman came over and said to turn my volts up quite a bit. The first bead went OK but then I was getting nothing but porosity. He came over and tried it on a different piece of plate and came to the conclusion I had too much stick out. I tried everything and kept getting porosity. The darn practice piece was hotter from grinding out the porosity than it was from welding. I turned the volts down some and got it to run without porosity but there was no way to finish the practice piece for a bend test. It was so hot I was just chasing undercut trying to put a cap on. I cleaned up and just went home. I should have left the volts lower where it was running nice.