We use 3/32" FCAW(E70T-1) with 100% CO2 shielding here in our shop, but the slag will sometimes pop off after the weld has cooled, without anyone chipping it. When it will do this, you have the parameters set pretty close. The slag should not be that hard to get off, many times the slag will act like an E7028 and just curl up and you can just brush it off. Find your wire mfg's recommended parameters and use them to find the ultimate settings for your particular wire. Some of the any position wires may have slag tht is more difficult to remove, but even that can be set for easy slag removal.
HTH,
John Wright

The weld joint region must be clean before you start weiding. Oil, water, paint coating and debris will cause weld defects like porosity and slag inclusion.

John Wright is absolutely correct in everything he said, but please allow me go one step farther. The same holds true with stainless steel FCAW, using the same facts John presented. Since you didn't mention if you were talking about carbon steel or stainless steel, I just wanted to add to John's response. Thanks..

Chuck

Generally speaking, FCAW slag is harder to remove when the volts/amps are on the low side or if you travel too fast. In fact that is one of the most common mistakes we run into in our shop; that the welder is not using at a high enough heat input.

Also, it sounds like you are using self-shielded FCAW which tends to be less smooth that gas shielded FCAW.

Since you are new to welding - heat input is determined by a combination of factors. Higher volts and amps, or a lower travel speed, (or both combined) will lead to a higher heat input. One of the troubles with low heat input is that the weld puddle freezes quickly and may not have a chance to smooth out. That causes all kinds of nooks and crannies that grip the slag. Not necessarily a "bad" weld, but one that is difficult to clean.

Now, don't go making drastic changes to your settings, that will lead to other problems. Instead try to make small changes and note the results. To start out, I would try slowing your travel speed a bit and maybe increasing 1 or 2 volts. Make sure you have enough wire feed speed to avoid burn-back to the contact tip. Keep in mind that the "perfect" settings for a flat or horizontal fillet weld on 1/4" steel will be different than what works best for a vertical groove on 1/2" steel. But with time and practice, you will learn what works best.

Have fun with it.

Chet Guilford

So if I was to use self shielded wire as well as
using 100% co2 it would be ok and likely produce an easier slag cleanup?

Regards,

Matt

HERES WHAT I KNOW MY FRIEND. I USED ALOT OF SELF SHEIDING FLUX CORE. MAINLY LINCOLN NR 212 AND NR 211. FOR GENERAL PURPOSE FABRICATION THEY WORK GREAT. ESAB AND OTHERS HAVE GOOD WIRE,ALSO. AS MENTIONED ABOVE CLEANLINESS IS A BIG PART OF SLAGS ABILITY TO BE LIBERATED. A SKILLED WELDER THAT I HAVE WORKED WITH USES NOTHING BUT ESAB DUAL SHIELD WITH A ARGON / CO2 MIX. THE TWO OF US HAD THE OPURTUNITY TO WORK SIDE BY SIDE ON THE SAME PROJECT. HERES WHAT I LEARNED. IF YOUR WORKING IN THE FIELD FORGET ABOUT THE DUAL SHIELD. BETWEEN LUGGING CO2 BOTTLES AND THE WIND BLOWING AWAY YOUR SHIELD GAS IT DOESNT MAKE FOR A PLEASENT DAY. DUAL SHIELD IS EXPENSIVE. BETWEEN WIRE, GAS, AND EQUIPMENT(IF YOUR SET UP FOR FLUX CORE ONLY). IF YOUR IN THE SHOP ,HAVE THE CASH, AND WANT TO RUN FAST, DUAL SHIELD IS THE TICKET. IF YOU CAN DEAL WITH THE SMOKE AND/OR YOUR OUTDOORS, OR JUST NEED GOOD GENERAL PURPOSE WIRE, FLUX CORE WORKS FINE. ABOUT THE SLAG DIFFERENCES. I CAN GET JUST AS GOOD A PEEL OFF WITH NR212 AS HE COULD WITH DUAL SHIELD. IT JUST TAKES TIME,PRACTICE AND CLEANLINESS. RUN FORE HAND IF YOU WANT PENETRATION. RUN BACKHAND IF YOUR RUNNING THIN. PLAY WITH YOUR HEAT AND WIRE SPEED ON SCRAP. GET 'ER DIALED IN JUST RIGHT AND THAT SLAG WILL POP RIGHT OFF. MIGHT SEE A GOOD WELD TOO! HAVE FUN!