A good day gone bad with 81Ni1-h. Please Help?

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Ok, Here we go...Alittle background about myself. I've been building communication towers all over for 14 years and got into the wonderful word of welding about 2 years ago. I dove in head first and 110%. I went out and bought a 302 Trailblazer,12 VS suitcase (love it) torches,trailer and built a tight little welding rig. I usually weld upstairs(top of towers) with .045 or .068 Flux cored wire. I have a job coming up structurally upgrading a monopole cell tower with 1 1/4'' thick gussets 18'' to 6' tall.  The SPECS. on the job require an electrode of the 81t or 8018 ballpark. Being that I'm not to great with a stick I choose Lincolns UltraCore 81Ni1A75-H in 1/16th. Brand new out of the box, loaded it into the feeder and away I went.Set up both machines per Lincolns spread sheet at 150ipm and 25-26 volts. Did some test passes and everything was great. I then bumped everything up to 175ipm and 26-27 volts in the flat position with a CTWD of 3/4 to 1''. Everything thing was great, man I love this wire. All was good, started tacking up my parts and started welding away. Note that gussets are all beveled to 5/8''. Most of the day was  going well till I ran out of gas(75%-25%). Major porosity!! Got the grinder and hard wheel and went to work. Changed tanks, purged the feeder set the CFH to 40 and continued. The larger the bead the more porosity I got toward the end of the pass. I tried smaller stringers and that seamed to help. One pass would be great and the next would be compeletly awful. I tried different drag angles, different push angles, running straight, weaves,circles, adjusting wire speed,volts, and stick out. The porosity seamed to be happening at the end of the weld bead. I was letting the parts cool down as this wire seems to burn pretty darn hot. I was also pre heating the cool parts because of the thickness. I attached some photos of the start of my day and as it progressively got worse. The last was when I quit for the day, to frustrated to continue.Tired of grinding and to lazy to pull out all the hose for the Air Arc.Any help would be great. Thanks. Attached Images
Reply:This is a riot.  I weld on cell towers too.   In fact I do the same thing as you at times....OK most of the time.  There is a thread here on welding with coreshield 8 which is similar to what you are using except its self shielding.Here is the link.http://weldingweb.com/vbb/showthread.php...ght=coreshieldIt may help.  I am trying to get a cert with Nr 232 OR 233 now for the next job.DavidEdit:  Do you drive a converted ambulance?Last edited by David R; 05-24-2009 at 09:28 AM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:David, I was hoping that you would hit back on my post. I followed your  thread on the monopole job. The engineers on these jobs can be pretty wacky. Like not allowing you to burn the galv. on the inside of the pole?? What was that about. Coreshield 8 from what I understand is a E71-t1 wire. The people that I'm working for are demanding that I use  a 81-t1. I am having a hard time finding a self shielding wire with this rating. What do you think of all the porosity issues I was having. I'm stumped.The engineer also suggested NR-208 XP , I havent looked into this yet.
Reply:Coreshield 8 and NR232 or 233 are in the same class.  All self shielding wire with 8018 properties.  I run a lot of stick because of the wind, but......   The next job is 420' of vertical up, so I need to get good with the wire.  I have migged a lot until they called for 8018.  I would need ER80S D2 to be "legal".I figured the dual shield would be as useless as the mig on a windy day and its always windy up top.I do most of my work at the base.The porosity I can't help you with because I have never ran that wire.  All I can think of is turn your gas flow DOWN and keep the gun closer and pointed more at the weld when you finish. Too much gas flow can cause turbulence and induce Oxygen (air) into the weld.  I would be using a 5/8 or 3/4 nozzle.Fellow tower WeldorI sent you a PM this morningDavid Real world weldin.  When I grow up I want to be a tig weldor.
Reply:I'm out of my comfort zone on this one but when I seen 40 cfh gas flow I thought this was quite high as well.Tough as nails and damn near as smart
Reply:I'm looking at the sheet I printed out and Lincoln says for this wire the flow rate should be 40-50 CFH. I thought that I might have been a little on the low side. I don't know?? And I hate not knowing.
Reply:we had similiar problems, but we burn solid wire, and when you said everything was fine until you switched bottles,got me thinking about the problems we had. after trying everything we could think of to correct it we called our supplier (Airgas) they swapped the bottle out and solved the porosity problem. we still don't know if it was a different gas mixture or what,and i don't know if they are pulling our leg, but they said if it happened again to take the bottle and lay it flat on the ground and roll it around for 4 or 5 minutes to mix up the argon /CO2. make sure the cap is on. never tried it so i don't know how true that is. i don't know if that's your problem, just something that happened to us.          good luck:
Reply:Sometimes the Mig Wire has a mind of its own...It could have just had a bad spot in the spool...I have seen that more times than I care to admit!!   Its frustrating as hell...Gas coverage is always a concern...Make sure that your cup is clear.  Watch how much spatter spray or dippy do you put on the cup...As your pressure dropped, that effects yo coverage alot!!!  Once you get porocity...It can travel with you even after you THINK that you have ground it all out...when I get into that jam...I leave a space between the stop and restart...If everything runs good...go back and struggle with the small area...if you continue having porocity...break down your machine and trouble shoot it...Good luckJonesy
Reply:cajun,You don't have to roll a high-pressure cylinder of mixed gas around.  The gas is already mixed inside the cylinder.Rolling the cylinder around just makes you sweat for no benefit, and scratches up the cylinder.Big wire and big amps usually calls for a kind of big gas flow, no little dainty in-the-shop-with-100amps-and-0.030-wire gas flow of 20 cfh.  As Jonesy70 suggested, run a test bead all by itself and check for porosity.  If all is good there, the previous porosity was from when you ran out of gas!  If you -still- have porosity on the test bead, then start checking the machine and trouble shooting.  Bad gas cylinder (it happens sometimes), bad connection in the gas line somewhere (torch to machine, cylinder to regulator, regulator to back of machine, etc), etc, etc.  The best laid schemes ... Gang oft agley ...
Reply:Moonrise, I'll agree and disagree with your statement.  Depending on how the gas was mixed at the supplier there is a possibility that certain gasses can stratify and not mix properly. We used to have issues with high pressure tanks with helium mixtures doing this IF they were partial pressure mixed and slowly filled. The gas analyzer would give readings that did not match what the math said should be correct after the tank was filled. Rolling the tanks was one way to correct this and get the analyzer to read correctly. Those tanks if left alone, could sit for days and still not analyze correctly but they would get closer to the correct reading as time went on.HOWEVER... Usually we would just load the tanks up and take them for a 10-15 minute drive. This accomplished the same thing as rolling or flipping the tanks repeatedly ( and a whole lot easier) My guess is that after being mixed, then trucked to the supplier, then transported to the job, the tanks were most likely thoroughly mixed, so in this respect you are correct that rolling the tanks would have no effect ( I doubt he mixed his own gas, but some do).My guess is that they filled the tank with the wrong gas, if the gas is the issue.