Further Down the Rabbit Hole, or Plasma Cutters, MIGs, and Chop Saws oh my!

[bss1]

I'm using 75/25. The regulator just measures pressure--I don't have a flow gauge. I've got the pressure set a little above 30 psig. Next time I fire it up I'll have to make sure I'm getting flow out the nozzle. I can add a rotometer, but doubt I need one.

30 is too high. 12 to 15 should be sufficient. You should be able to hear and feel the gas coming out. My machine has a purge setting that allows purging the lines or air and filling with gas before welding. If I don't purge at the beginning of a session, the start of my weld will look like yours. If you don't have a purge setting, you can release tension on the drive or turn wire feed to 0 and pull the trigger to purge. But since all of your welds have the porosity, I think there is an issue with a lack of shielding gas coverage. It could be due to the issues Mikey stated, but something is wrong with the coverage. Also if you are welding on hot rolled steel, you will need to grind off all of the mill scale to get the best looking welds. Make sure you are getting a good ground. At first, try sticking with the settings on the door chart as someone else mentioned and see if that helps. Try holding your torch closer to the work piece also.

That is a real nice machine and you will get it figured out soon.

Brad

 

[Rustrp]

Here's a brief update. I did some MIG practice over the weekend, and the beads look pretty ugly. They did, however, significantly improve. Other than the obvious speed/feed issues, I'm also getting a lot of porosity on the top surface. I remember seeing something about what causes that, but I can't remember. I did learn that just because everything goes dark doesn't mean I've blown a fuse--I have an auto-darkening helmet.
View attachment 229365
View attachment 229366

The HF band saw arrived tonight, as did the 44" tool chest. I haven't unpacked the band saw, but the tool chest is pretty impressive. It will make a nice home for my Gerstner chests and Reed vise.

I think it's your helmet.

 

[ACHiPo]

30 is too high. 12 to 15 should be sufficient. You should be able to hear and feel the gas coming out. My machine has a purge setting that allows purging the lines or air and filling with gas before welding. If I don't purge at the beginning of a session, the start of my weld will look like yours. If you don't have a purge setting, you can release tension on the drive or turn wire feed to 0 and pull the trigger to purge. But since all of your welds have the porosity, I think there is an issue with a lack of shielding gas coverage. It could be due to the issues Mikey stated, but something is wrong with the coverage. Also if you are welding on hot rolled steel, you will need to grind off all of the mill scale to get the best looking welds. Make sure you are getting a good ground. At first, try sticking with the settings on the door chart as someone else mentioned and see if that helps. Try holding your torch closer to the work piece also.

That is a real nice machine and you will get it figured out soon.

Brad

Brad,
It is 30 psig, not 30 CFH. Not purging could definitely be an issue--I didn't do anything other than install the spool, feed wire, and start. I ground/sanded the area I was using to practice on, so I don't think it's from contaminated steel.

I'll play around more this weekend and see what happens.

 

[dlane]

Looks like air getting in there to me.
I bought my bottles lifetime lease $$$ not rented 30+ years ago from Airgas in Austin Tx , didn't pay to much attention when exchanging them at other supply shops there or Arkansas over the years.
Turns out at some point they were changed out with rental bottles, "receipt long gone "
Here in cali they're telling me I have rental bottles and want$$$ to fill them .
Moral of story , check the ring on top of bottle before and after exchange , don't let them switch
rentals have co name stamped into them ,
Lifetime lease bottles the ring is blank.

 

[Rustrp]

My first guess on the porosity when using solid wire is shielding gas. I think I mentioned a flowmeter somewhere in this discussion. In 99.9% 0f the cases you can rule out the gas flow through the gauge if you have a flowmeter. I saw your comment on psig/cfh and if your low pressure gauge is marked psig then it's probably a cheap knock off Radnor. CFH/cubic feet per hour is the correct way to measure flow. How much flow is based on who's paying for the gas, you or the employer. Tig welding is usually done with 12-15 CFH and MIG is 25-30 CFH. You should be able to feel the flow if you put the nozzle close to your face. If your machine doesn't have a purge mode, zero out the wire feed speed and pull the trigger. Another way would be to put the tip of the nozzle in a cup of water.

Cross draft is always a factor when you use shielding gas.

PS. My guess is if it came in the box with all the accessories it's a Miller regulator/flow gauge, but the flow rate side should be measured in LPM/CFH.

 

[ACHiPo]

Looks like air getting in there to me.
I bought my bottles lifetime lease $$$ not rented 30+ years ago from Airgas in Austin Tx , didn't pay to much attention when exchanging them at other supply shops there or Arkansas over the years.
Turns out at some point they were changed out with rental bottles, "receipt long gone "
Here in cali they're telling me I have rental bottles and want$$$ to fill them .
Moral of story , check the ring on top of bottle before and after exchange , don't let them switch
rentals have co name stamped into them ,
Lifetime lease bottles the ring is blank.

The gas shop told me I own the bottle, but they will refill or exchange it for a few bucks (I think $30?)

 

[ACHiPo]

You should be able to feel the flow if you put the nozzle close to your face. If your machine doesn't have a purge mode, zero out the wire feed speed and pull the trigger. Another way would be to put the tip of the nozzle in a cup of water.

All good suggestions. Thanks!

 

[Rustrp]

All good suggestions. Thanks!

Your machine has auto or manual setup. For you as a beginner I suggest going with the auto setup, then adjust your voltage towards the low range for the voltage setting. I'm guessing in the auto mode the wire speed (amperage) is set, and other than the porosity the weld looks too hot. Check the parameters inside the door for volt/amperage (wfs) settings for the wire. The corner joint you chose isn't the best place for you to begin practice. Try flat first then work on other joint designs/configurations. I'm not goint to steer you wrong. Understanding what those two knobs (settings) on the front of your machine so and how they affect the weld bead is important. I talked my son through a welding problem a few weeks ago. The question of which way do I turn the knob becomes easy once you understand their purpose. I got a verbal description over the phone and a few minutes later a photo.

In regards to shielding gas; Make sure the gun is installed correctly, no o-rings are missing and the hose from the gas solenoid is connected. Occasionally they miss a QC step. Pull the trigger when you set the gas flow, it gives a more accurate flow rate, even if you can't see it. On most gauges the needle will rise when you release the trigger so you want to know what's being delivered as you weld.

 

[BFHammer]

I have the same machine that you just purchased. Based on my experience I think bss1 and Rustrp are on the problem. It looks like a shielding gas issue. If the metal is clean to start with (no mill scale) then lack of shielding gas is the first probable cause for the porosity.

I'm don't know how to compare PSI to CFH - with my machine 15 CFH seems to be the sweet spot. If your LWS store is convenient I would stop by and "trade" them that regulator for a good flowmeter.

 

[BFHammer]

I may have missed it in an earlier post, but are you running the machine on 110 or 220? And as suggested above are you sure that your setting are matched with the input voltage?