fork

what comes with this kit you got, is it a different liner for the lead or is it a spool gun. if its not a spool gun, its not gonna be easy

Engloid

Definitely not. Next time you're on the interstate and pass a big gasoline tanker truck (like a Pilot or Exxon Truck), look at the welds on them....they're all or nearly all MIG. The deposition rate (rate at which you deposit metal into the puddle) can be MUCH higher with MIG. Therefore, if you're making a big weld, MIG is hard to beat. I worked at the Heil trailer plant for a while, and the guys there would regularly run their mig machine at 600+ inches of wire per minute.
Yes, as you probably learned, that's just due to high friction in the lead from the machine to the gun. It's like trying to push a wet noodle through a piece of bread. It just doesn't work well.
I'd only reccomend this if you're having to run your machine as hot as it will go, and still not able to get a hot enough puddle to weld smoothly. So, if you have thin wall pipe, preheating it may make it such that it's even harder to keep from burning holes in it.
I know you know since you've seen and used one, but for those that don't, I'll explain a bit more. Your average mig machine has drive rollers in the machine, right up near the spool. These are "push" machines. A spool gun is when you have a little spool of wire that's inside or attached to the actual gun. The "push-pull" machines have the spool at the machine, rollers at the machine that push the wire, and rollers up in the gun that pull the wire. This greatly reduces problems with wire kinking up in the liner or before it. In other words, consider trying to push the noodle through the bread (assuming you had a hole in it already. It will kink up and be difficult. Then imagine having it fed through already and pulling it from the backside. It will pull through a lot better than it will push from the other side.

jdm monkey

yeah, its (not sure) plstic liner with a different guide roller so that the alum. wire will roll out w/o resistance

fork

make sure you set the rollers and tesion on the spool well or you'll get nasty birds nests

Jcushing

k i got a tank of full argon now and some 4043 .035 weld wire so lets see how i do....

TRAILERxPARKxINC

well for the bird poop welds theres this neat lil invention called a 90 grinder it works pretty well maybe invest in one of those and tig it if its the only one your doing it will look much more professional

easy way to learn also after you get 2 peices butt welded bend them back and forth until one breaks if it breaks at the weld your not doin it right

Jcushing

well i tried it, let me say what a PITA. after finally being able to set up the machine to do some "ok" welds the ****** jammed twice. i DONT have a spool gun but will before i try aluminum wire again. i was using .035" 4043. 5053 might have been stiffer but i dunno, i didnt try that. imma gonna stick with SS