Quick FLUX question... Need help!

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Real quick question. I was using my MIG with .035 innersheild flux wire to build a firewood rack. Well, the first few sets of welds turned out sweet. Great penetration on 1/4 square tube. I was even able to make a nice looking weld when bridging a 1/2" gap. But after I ran out of that spool I put a new one in and all the welds seemed to look like crap. If I can explain it right, I could actually see the weld puddle forming little balls instead of flowing. None of the settings were changed before or after the spool change. In my head there are three options. #1 maybe a crappy roll of wire, #2 welder was getting tired after the somewhat continuous use, or #3 I was getting tired and just started getting crappy all together.Let me know what you guys think. If you need pics I will be forced to supply  Oh, by the way the machine is a Lincoln 3200HD (home depot) settings were D on the heat and wire speed around 2.5Thanks in advance!
Reply:Same brand and spec wire?
Reply:#1 and 3 are likely culprits.Same wire (brand and spec and wire diameter) on both spools??  You didn't accidently have a spool of 0.030 NR-211-MP wire instead of 0.035, all running through an 0.035 tip?
Reply:Yeah, same wire same tip... nothing to my knowledge changed. I did however somehow get a pile up in the wire right after the feed motor, but after I cleared that up it fed fine.I guess it was probably me being tired. 10 hour day of work and then coming home to build that until 11:30 can take a toll on you.
Reply:Wow, I feel like a moron. I went out and checked again to see make sure the wire was the same and nope.... .030 wire through a .035 tip. I guess i wasn't paying attention. I just grabbed the roll and threw it in there in a hurry.
Reply:When you went back to .035, did it become OK.  When some wires go through the drawing dies, some of the wire can become void of the flux ingreadience and the weld will do as you said.  The years I worked for Linde we had a lot of problems with voids in the FC wire.   JohnSMAW,GMAW,FCAW,GTAW,SAW,PAC/PAW/OFCand Shielding Gases.  There all here. :
Reply:I actually havent reverted back to .035... I guess I don't have any on hand.But that void problem does sound like it could be a problem.One more question, why would .030 wire through a .035 tip cause a problem? I guess I don't see the relation.
Reply:Originally Posted by ca180I actually havent reverted back to .035... I guess I don't have any on hand.But that void problem does sound like it could be a problem.One more question, why would .030 wire through a .035 tip cause a problem? I guess I don't see the relation.
Reply:Originally Posted by ca180One more question, why would .030 wire through a .035 tip cause a problem? I guess I don't see the relation.
Reply:I would never recommend using a larger contact tip than the diameter of wire being used, the main reason being that the contact tip is the only place in the circuit where the wire can pick up the needed current, if the whole I.D. is too large the wire will not pick up sufficent current (not to be a smart--s) but that is why contact tips are called "Contact Tips" Excess cast and helix will wear a contact tip out faster, you'll see this as the hole in the end of the tip becomes egg shaped, or will wear to one side, this is due to the wire wanting to take the same shape as it is on the spool, the smaller the spool, the tighter the cast, if you can, always run the biggest spool of wire your machine will take. As for aluminum tips (spool guns, and push-pull guns) The manufacturers of these tips generally oversize the tips by .005-.007
Reply:Just buy .035 and be done, it's the right way.And if you are using the small spools, now is the time to buy the $8 adapter (2" spool adapter) and start using the larger spools, they last much longer.KRS***************************************Lincoln AC225 stick welderLincoln HD100 WeldPak flux core wire feed welderThree of the cheapest grinders money can buy