Porosity and dirty looking welds driving me crazy!
I recently purchased a power arc 160 sth with the foot pedal from Everlast Canada, and am having a huge issue with my welds that I'm hoping somebody can help me with...no matter what I do it seems, about 8 out of every 10 beads I run have porosity and end up looking contaminated around the edges. Sometimes if I let the welder sit, then try another weld an hour later, the first bead comes out beautiful! Then I start getting browned edges, flaking/grey on top of the weld, and porosity. Here's what I've tried so far;
-Checked lines for leaks by pressurizing, and then shutting off the tank and leaving it for 15 minutes or so. Found a very small leak on hose connection to flow meter/regulator, and tightened it. Leak is gone, problem still there.
-took the torch apart and found that the hose clamp on the torch end for the gas was slightly loose. Replaced clamp and connection is now tight.
-Checked torch hose for leaks by dunking in water and blowing through hose, couldn't find anything.
-Checked all connections with soapy water while system was pressurized. Nothing.
-Swapped over to a bigger (#8) cup.
-Checked that torch assembly was air tight by blowing into cup with everything tightened. Seems good.
It seems as if somehow, air is being drawn in, or something is contaminated. All testing was done on 1/4" steel plate, ground to shiny, clean metal. 3/32 E3 tungsten (purple band) and 15cfh indoors with no wind. I thought maybe my flow meter was reading incorrectly so I even borrowed a gas flow tester that goes on the end of the torch and found the gauge is off a bit. 11LPM (about 22 Cfh) on the flow meter is actually putting out 15 Cfh at the torch.
The only thing I can think to do is maybe try a new tank of argon? Called the welding supply and they said it should be a good batch of gas because I'm the only one who's called about it. I've also only welded about 4 hours maybe and already used almost 3/4 of the tank. I'm not sure the exact size but it's about 3 feet tall to the top of the valve, so a fairly large tank.
Any ideas?!?! Thanks for reading!
Adam
Sent from my iPhone using Tapatalk
Reply With Quote
Originally Posted by Rambozo
), I use "just enough" and adjust post flow accordingly, and I will "fine tune" from there by swapping cup sizes, increasing/decreasing stickout, increasing/decreasing post flow, and installing/removing the gas lens (again, depending on what material I'm welding). Too much LPM is just as troublesome as too little, and bigger cups use more gas. 
), so that I don't chance getting porosity from the lack of gas flow. I'm not welding on bridges or terribly critical items most of the time, and I find that my method works fine a majority of my projects. Go from one extreme to the other in situations like this and it will help you better visualize what's going wrong, what you need to do to fix the issue, and what to look for when things do begin to go wrong.
