mig and flux core tips and techniques, equipment, filler metal
rlrsk8r
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    Mon Aug 01, 2022 9:31 pm

I have a Hobart betamig 200 welder (One of the very first Hobart sold as a single phase welder, which I bought at the Ohio factory when the first one came in from field demo) which has been performing worse and worse over the past few years. Granted, I’m a hobby welder and I don’t use the welder all that often.
Problem that I’ve been having is that the wire (.024) burns off and sticks to the tip while using it, no matter what the settings are (Argon-CO2, 15 CFH). The tip is a quarter of an inch back in the nozzle. I’ve been fighting this problem for a long time.
What I recently noticed is that the outer rubber hose on the stinger is cracked just behind the torch. I’m assuming the gas flows in this rubber outer covering. The crack runs about halfway around where it goes into the torch, probably leaking the shielding gas out of the stinger?
Could this be causing my problem?
cj737
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    Thu Sep 29, 2016 8:59 am

Burn back is often associated with too slow a wire feed speed. I’d also run 25cfh for your gas.
rlrsk8r
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    Mon Aug 01, 2022 9:31 pm

I discovered that the outter covering on my torch was split just before the torch. Thinking that this was causing the shielding gas to leak out and not cover the arc, I wrapped the covering with a healthy layer of duct tape.
I fired it up today only to find the same condition - Burn/STICK to tip.
For years I've used 15CFH with same wire speed. I run my speed at about 5 (50%). Hadn't had problems until the past couple years or so.
Being a hobby welder, I don't weld all that often so I've been unsing these same settings.
cj737
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    Thu Sep 29, 2016 8:59 am

When the wire burns back to the tip, it’s due to the wire not being able to overcome the short circuiting. So, either your speed is incorrect, or the liner in the gun is not allowing the wire to spool off quickly enough. Has nothing to do with shielding gas.

15cfh is too low. The fact that you’ve used that setting for years is only testimony that you’ve been wrong for years. The sound of a good MIG weld is sizzling bacon, not cracking, no popping, no sputtering. Post a picture of some of your welds and we can see if the machine set up correctly.

If the voltage setting is very high, smaller gauge wire needs to be fed faster than 0.030 or 0.035 wire.
Jack Ryan
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You might want to check your contact tip as well. If it is too big (worn or the wrong size or the right size but for Al), you may get arcing (and sticking) there.

Just a thought.

Jack
corn chip
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    Wed Oct 05, 2022 10:20 pm

why is 15cfh to low ? thats about all i ever use and seems to work fine. if its enough gas to cover the weld then whats the point of going higher
cj737
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corn chip wrote: Wed Dec 21, 2022 6:55 pm why is 15cfh to low ? thats about all i ever use and seems to work fine. if its enough gas to cover the weld then whats the point of going higher
What you think matters less than what is actually occurring. Post a picture of some of your welds so the inadequate gas coverage can be identified for you. A rule of thumb is 2x the cup diameter of your cup size when welding. That gets lost to “TIG” process and overlooked for MIG. I’ve never welded with a MIG running less than 20cfh and often run nearer to 35cfh for high voltage, large wire applications.
tweake
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corn chip wrote: Wed Dec 21, 2022 6:55 pm why is 15cfh to low ? thats about all i ever use and seems to work fine. if its enough gas to cover the weld then whats the point of going higher
open to correction as i'm rusty as hell with mig, but mig uses active gas so its not just for coverage.
tweak it until it breaks
cj737
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tweake wrote: Thu Dec 22, 2022 2:07 am
corn chip wrote: Wed Dec 21, 2022 6:55 pm why is 15cfh to low ? thats about all i ever use and seems to work fine. if its enough gas to cover the weld then whats the point of going higher
open to correction as i'm rusty as hell with mig, but mig uses active gas so its not just for coverage.
Another great point indeed.
corn chip
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    Wed Oct 05, 2022 10:20 pm

i understand its a active gas. what we commonly refer to as mig , is actually mag. but still im not sure ive seen any benefit to a overload of gas. maybe im missing something however
corn chip
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    Wed Oct 05, 2022 10:20 pm

its possible ive over looked something. maybe a active gas has more penetration or something with higher cfh. https://www.twi-global.com/technical-kn ... ig-and-mag
corn chip
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    Wed Oct 05, 2022 10:20 pm

i found some rule of thumb info per the fronius site. 10liters/min for every mm of wire diam. converted thats 19cfh with .035. this is assuming the wire manufacturer doesnt have a specific gas flow rate for the wire. some might ,some probly dont. so rule of thumb should be fine. guess ill bump mine up to 19cfh
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