Mig welder gun tips

[loanrangie]

Couldn't find the original post but a while back i was having wire feed issues with my Cigweld 130amp mig, i generally weld outside so use flux cored wire (gasless). Hadn't got around to doing anything about it until recently as i was getting back into finishing my trailer, doing an online search i came across some posts where it was mentioned that going up in size with the tip when using gasless wire can help reduce binding. So spent the $6 for 10 x 1.0mm tips and mig is working perfectly now.

[Slunnie]

What size wire are you using?

I've heard of others doing this also, I think they might be using 1.0 with 0.9 wire and think its good.

We solved torch problems by bigger size contact tips initially and in the end solved them with 270amp cam lock tip guns. Now virtually no probs with guns.

My big MIG tip is run oversized torch assemblies!

[loanrangie]

What size wire are you using?

I've heard of others doing this also, I think they might be using 1.0 with 0.9 wire and think its good.

We solved torch problems by bigger size contact tips initially and in the end solved them with 270amp cam lock tip guns. Now virtually no probs with guns.

My big MIG tip is run oversized torch assemblies!

Exactly, .9 wire with 1mm tip and its like a new a welder. Of course i ran out of .9 wire before finishing so back to .8 and a .9 tip.

[Toxic_Avenger]

Knurled rollers and your FCAW welding woes will end. You should be using them if you are not.

The problem with bigger tips is that that wire wears it out prematurely. Welding gasless accelerates wear further.
Wire has a case and helix- when off the spool (not under tension) it will form a circle or a much larger diameter than that of the spool, and there will be a helical rise. What ends up happening on an oversized tip is the wire will form an exaggerated circle as it feeds out the tip, and will wear the contact tip. They are a copper alloy afterall. Add plenty of heat cycles and it anneals. Remove the cooling shielding gas flow (running gasless wire), and the problem multiplies.
It can get to the point where the wire momentarily breaks electrical contact with the tip. And you get sputtering, inconsistent arc voltage and a range of other defects.

Agree with the torch. Abimig 455 or GTFO.

Bonus fact- buy good tips and consumables. Cheap tips don't last nearly as long as a good name brand tip like Tweco or Binzel. Look for their brand on the pack. And avoid anything that is 'tweco style' or 'binzel style'. If you really want to splash out, you can opt for better alloys like CCZ or silver coated.

[loanrangie]

All that may apply if you weld a lot which i don't, for my purposes the reversible wheel knurled/plain works well and not the cause of my feed issues.
It was more a binding which the larger tip has fixed, i don't care if tips don't last for the amount of time i weld they will last more than a year.

[Bigbjorn]

Exactly, .9 wire with 1mm tip and its like a new a welder. Of course i ran out of .9 wire before finishing so back to .8 and a .9 tip.

For years I have used 0.9 wire and 1.0 tips in my Transmig 190. Works well. Whole machine has been great. Only bitch I had was BOC rent on the cylinder. Solved that about 5 years ago by finding a supplier who didn't charge rent. Cost of a cylinder including gas charge was less than two years BOC rent. My use is negligible nowadays and BOC rent was ludicrous in comparison to usage.

[workingonit]

...Wire has a case and helix- when off the spool (not under tension) it will form a circle or a much larger diameter than that of the spool, and there will be a helical rise. What ends up happening on an oversized tip is the wire will form an exaggerated circle as it feeds out the tip, and will wear the contact tip...

Could you point to a reference as I couldn't find any? Does it have another technical name? Found reference to the term in CNC machining but may be entirely different matter, to do with too higher feed rates on very tight turns where axis control is not fast enough to meet required form.

As an amateur I would have thought the feed rollers would deform wire from the roll into a curve that would approximate what would be needed to get through the sheath and as you indicated comes out in a large gentle curve rubbing on one side of the tip - but as you are saying, only to flip contact position as helical rise takes affect - if i understand correctly.

Oh, and yes, I went to a slightly bigger nozzle on welding shop recommendation. Plus some blue stuff to dip the tip in to inhibit spatter accumulation?

[Toxic_Avenger]

Typo- it's 'Cast' and 'Helix'. Cast being the resting diameter and the helix being the desire for the wire to form a helix.
Cast and helix is more a concern for precision layer wound wires. Most gasless wires have random wound spools. So layers can actually settle and bind in transit, while stacked in pallets etc. So that is a feedability liability in its own right. Most gasless wires are random wound. So it's a dog's breakfast in that regard.


There are so many other variables in MIG.
Flux cores wires have a lower column strength than a steel wire. Ie it wants to buckle on itself while being fed thru the torch- like trying to push a rope.
Feed roll tension comes into it a lot too. If too tight, then the wire can and does flatten, increasing its overall effective diameter. Too loose = no feed. Ideally you need just enough tension to get the wire thru the torch.... no more.
Liners matter also. they can gum up- especially with FCAW wires as they have a coating of schmutz on them at the best of times.
Nozzle selection is a pretty simple one- small enough to keep the spatter out of the tip, and get a proper contact tip to work distance on the job (particularly for a fillet weld), and large enough to get a suitable gas flow if applicable. Some of the better torches out there have 'gasless' nozzles available for them which insulate the nozzle for wayward spatter.