ntaj*ep
1/2 ton status
WTF, is up I have a Miller 175 and it is making some really porus weld beads. I need the experts to chime in on this one. Some welds are just fine while others are really bad.......
CK5
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Porus welds, experts please help.....
- Thread starter ntaj*ep
- Start date
big jimmy 91
1/2 ton status
Need to know what you are welding and under what conditions...
Then someone may be able to help diagnose the trouble
Then someone may be able to help diagnose the trouble
ntaj*ep
1/2 ton status
1/4" in my garage......
domb question got the gas on? and or bad batch of wire? or lots of dirt on surfuce? just a few ideas.
sled_dog
1 ton status
dirty surface and no gas are the top causes of porus welds in my experience.
ntaj*ep
1/2 ton status
Mirror finish, gas on set to 22, wire speed at about 75 and power at setting 4.....
ntaj*ep
1/2 ton status
Me too....sled_dog said:
Are you getting gas flow at the nozzle? Could be plugged up gas diffuser. Could also be disconnected at the drive wheels or where ever the small gas line attaches to your lead. Other than that there is wind, and all the other usuals.
big jimmy 91
1/2 ton status
At the shop I have worked for , a cause of pourosity has been gas leaks at all the different connections in the lines.
The guru welders there say that at times it can allow air into the system causing it to screw up on you.
I have allways leak tested , found tiny leaks , repaired them and it stopped the poor welding results.
I guess it allows air in when it sits long enough to bleed off the gas and allow air into the system
Just have to ask , are the doors or windows open , or some kind of air mover blowing the gas away?
Sometimes it does not take much.
Or is there any oil on your material (new metal)
The guru welders there say that at times it can allow air into the system causing it to screw up on you.
I have allways leak tested , found tiny leaks , repaired them and it stopped the poor welding results.
I guess it allows air in when it sits long enough to bleed off the gas and allow air into the system
Just have to ask , are the doors or windows open , or some kind of air mover blowing the gas away?
Sometimes it does not take much.
Or is there any oil on your material (new metal)
How much 'stick out' are you running on average? Anything more than 3/8" stick-out is enough to end up with porosity.
Try 25 on the flow meter and see if that helps. 22 is on the low side IMO.
rene
Try 25 on the flow meter and see if that helps. 22 is on the low side IMO.
rene
ntaj*ep
1/2 ton status
tRustyK5 said:
I thought that too, but the guys at the local welding shop said that 22 with the mix I'm using was OK. I stepped it up a little to 25-26 and its still no good. But I think I will stick with it as I have always run that myself.
I think the gas leak might be something, when I bought this unit it had no regulator with it. I got a new one and hooked it up turned the bottle all the way on and didn't hear anything so I figured WTH! Where does the gas enter the gun? The guy I bought it from claimed he re sleaved the lead, maybe he broke something? Or forgot to hook something up?
I have never had this issue before, where I couldn't solve it easily....
ntaj*ep
1/2 ton status
Holy shnikies dude! What machine is that? Mine is just a little 220v 175. I would guess the machine you guys are running is like a 250 or bigger.Jonny-K5 said:
The larger machines can push a ton of wire. Our machine at work I set at 475 IPM with .035 microwire (28 volt), and about 330 IPM for the 1/16" flux core (31 volts). I have burned through a 55 lb roll of flux core in a single shift (10 hour shift...)
Anyways, stick out is defined as the distance from the end of the contact tip to the work or puddle. You don't want to be more than 3/8" of an inch or you will get the Aero bar weld. Make sure you grind all the porosity out or it'll keep coming back...
Rene
Anyways, stick out is defined as the distance from the end of the contact tip to the work or puddle. You don't want to be more than 3/8" of an inch or you will get the Aero bar weld. Make sure you grind all the porosity out or it'll keep coming back...
Rene
Forgot to mention, you should be able to hear and feel the gas coming out of the nozzle when you pull the trigger. I hold the gun a few inches away from head and with the nozzle not facing me in any way (obviously)and hit the trigger. You should hear the gas flow, at least for a second or two.
Rene
Rene
Jonny-K5 said:
sorry, i meant ipm, not fpm.ntaj*ep said:
we have machines of all sizes. mostly use the little 110v lincoln 135plus's.
200ipm is fairly slow, its only the number 3 setting out of 9.most short circuit transfer welding is done in the 2-300ipm range.
you can weld anything from thin sheetmetal to thick plate steel at 200ipm, just by adjusting voltage. im sure its more efficient to speed up the wire for thicker metals, but its possible to do quality welds on a variety of thicknesses at 200.
not sure how your welder is set up, but when you say wire speed is 75, where is the dial at? each number represents 70ipm, so to get 75 ipm, you'd have to be a hair above #1 setting. im not even sure you can weld that slow. do you mean you have it set a 75% capacity? or about the 2-3 o'clock position on the dial? thats pretty fast for short circuit, you'd be pushing the wire into the pool pretty hard.
Esteban86K5
1/2 ton status
He probably means it's set at 7.5 on the dial. i have the same machine and it goes up to 10. 7.5 seems kinda high for a 4 setting. Mine goes a,b,c,d,e and I run 75 on the highest setting. But it probably won't give you porosity for running it that high. I'd check the lines for a leak. 
ntaj*ep
1/2 ton status
Thanks for the input bro, I have the wire feed set at a little over setting 7 or about 2 o'clock.......
As far as my issue with the unit goes I think the gas sol. might be sticking, as a side note the voltage might have been a bit high on 4 also. I couldn't hear the gas at the tip of the gun so I checked and the sol. didn't feel like it was working. I tapped it a few times and felt it start working, I then fine tuned the bead to almost perfection. I will be getting some test specs. on the sol. tomorrow. Grinding the few beads I had and re doing them was a total pain in the butt. But well worth it. I used some test pieces to make sure the unit was working then went to town. Thanks everone I will keep you posted. 
As far as my issue with the unit goes I think the gas sol. might be sticking, as a side note the voltage might have been a bit high on 4 also. I couldn't hear the gas at the tip of the gun so I checked and the sol. didn't feel like it was working. I tapped it a few times and felt it start working, I then fine tuned the bead to almost perfection. I will be getting some test specs. on the sol. tomorrow. Grinding the few beads I had and re doing them was a total pain in the butt. But well worth it. I used some test pieces to make sure the unit was working then went to town.
Thanks everone I will keep you posted. RSNHELL
Registered Member
95% of the time,in my experience,wind or a breeze will blow your gas away and create purocity in your welds on top of the afformentioned fixes.( I.E. garage door opened when windy outside, draft from fan to blow smoke away ,etc...)
Most of the common things have been covered already, one other thing that can be a problem is a bad bottle of gas. Sometimes the mix can be off, or the bottle can be mislabled. For example, C02 in a bottle labled for 75/25 etc. It happens...I've experienced it all.
