Welding Tips and Tricks

Greetings, All !
I have been having constant problems with a Miller spool gun running 4043 .030 wire.

The problem is that about half way through the spool, the wire keeps bird-nesting between the pull roller and the liner leading into the nozzle. This happens with 3 different brands of wire, and doesn't seem to matter if I clean the current tip or replace it with a new tip. However, the problem doesn't seem to bear its ugly head with a fresh, new spool of wire.

It's to the point that about half way through the spool, I can only get 6-8 inches of weld before the bird-nesting takes place (and many times with only one tack-weld). I end up spending much more time cleaning out the bird-nesting and re-feeding the wire than actually getting any welding done.

The problem doesn't seem to happen with 5356. It's my thoughts that because 5356 is a stronger alloy, it has the strength to push through the liner and nozzle. It's also my thoughts that the 4043 must have "soft spots" in the wire that help attribute to the problem.

Any tips to alleviate this problem and allow me to use an entire spool of 4043 without having to switch to a new spool would be greatly appreciated.

Thank you in advance.

Just a stab in the dark here, but try using a .035 tip with that .030 wire. You're right, 4043 is a soft alloy. It also expands greatly with heat, making the pass through the tip rather tight. The slightest drag here can lead to bird-nesting.

I don't really get why it only happens when the spool gets low, unless the drag on the spool is too high, which only makes sense if the drag is high enough to fight the feed rollers. Might be worth a look... Those little spools should "almost" free-wheel. Just tight enough that the spool doesn't unroll itself in the gun.

Other than that, can you adjust the spacing between the drive rollers and the entry to the liner to be any tighter?

The only other thought that comes to mind is to slightly increase the wire speed, so the melt-off happens a bit farther from the tip.

Steve S

Thank you for your reply, Steve.

As best as I can tell, the gun is a Miller SpoolMatic.

Concerning the drag on the spool:
The wire is coming off the spool well. The wire is bird-nesting between the pull roller and the liner, which tells me something with the liner and/or tip is causing the issue. If the drag on the spool was the issue, then logically, it *should* happen on a fresh spool as well.

I have tried adjusting the "squeeze tension" against the drive roller every way I can think of, but to no avail. There is no spacing adjustment between the drive rollers and the liner.

If it helps, the job we just finished is 2" schedule 40 pipe laying flat on 4" x 8" rectangular tubing. The melt-off point is considerable distance from the tip, because the nozzle just can't get any closer to the bead. And increasing wire speed just adds too much spatter... Want and prefer the "spray transfer" if possible.

Thanks again for your reply.

Oh... And to help clarify...
I can run spools of 5356 all day long and not have this issue.

I'm at a loss, then. The stick-out seems to be the only variable in the equation.

Is it possible to "smash" a nozzle into an oblong shape to get tighter in the space, and see if that affects the problem? I've done this with copper MIG nozzles for carbon steel work before, to reduce stickout.

Steve S

WALL-O-TEXT I've had to use a larger tip before like Steve has said an .035 tip for .030 wire. perhaps this is an issue that you have already mentioned. 4043 is softer but it still has somewhat of a memory to its original shape. when you start a fresh spool, the Outside Diameter of the spool is greater than when you run low and the coils are smaller. so perhaps this tightly coiled memory of the wire is causing issues being as soft as it is and causing a rub on one side of the liner where it catches and bird-nests. that would seem to follow the problem with it always nesting later in the spool. or the drive rolls them selves aren't the right size for that particular diameter of wire and are not rolling the memory out of the wire "enough" cause it wont take a lot or too much as you've said you've tighten them already as best you can. it says on Miller's sight that the spool can rotate 180 degrees, try doing that as well.

Of course this could all just be a burn back issue but that doesn't address the issue with it only happening on 4340 spools near halfway empty or less.

Here is a thought... I have run into this before... spatter can at times get into the coil and cause issues that are undetected. I don't know if it is what is wrong but it is a thought. I know I've run into similar feeding issues that you are talking about.

Thanks to all of you that have replied !! I really appreciate your input !! I'll try to address each one:

To Steve...
Yes, I could take a hammer and smash the nozzle, but I have a sneaky feeling that won't help (other than just getting frustrations out ).

To Oddjob83...
Your thoughts are close to mine. I didn't think of flipping the spool over to try to help reverse the memory of the wire! Good thought! Absolutely worth a try !!

To nickin372:
Back on TIG right now, but during a lunch break I will pull this gun's nozzle/liner apart and see if that's the issue. You mentioned "spatter getting into the coil". It's true that the "liner" is a coil of wire.

I think I remember in older days the "liner" used to be like a teflon tube the wire fed through. I say teflon, but I actually don't know what it was made of. It wasn't the "coil of wire" they have in the gun now. And unless my memory is failing me, I don't recall these burn-back / bird-nesting issues when those types of liners were used. Someone please correct me if I'm wrong here.

Again...
Thank *all* of you for your thoughts !!

Sorry I meant the wire spool. I know its covered but I have had spatter get into the tiny spots that there are and fuse to the wire then when you get to that spot on the roll it binds up and makes a mess.

If it's a liner issue especially an unlined one I've had great success with the outer part of motorcycle throttle cable which is available locally by the meter off a coil & is teflon lined - works well - or on a short straight spool gun small diameter nylon pipe used on oil pressure gauges / compressed air equipment works OK.