7018 AC flux won't melt away--help.

Tue, 31 Aug 2021 15:35:37 GMT

go to see Welding Machine for 7018 AC flux won't melt away--help.

I'm repairing a boat trailer and really hoping to get it done this weekend.  I'm using 1/8" rod and the flux won't melt away which stops the arc, the metal rod burns up into the flux.  The only way it'll sorta keep welding is if I force the rod hard against the metal which makes it hard to control.  I'm pushing so hard the rod starts bending and it still pauses from time to time then restarts on it's own a second later when the hot flux gets pushed away.  I've tried settings from 90 to 200 amps; things change but can't find a setting that works.  The machine is an old craftsman 30-200 "home & shop".  The first rods were old, so I tried some new ones, same results.  The new ones weren't sealed tho.  I've tried low amperage shorting to preheat the rod, still same.  It'll run 7014 fine, but I'm after the penetration and strength of the 7018.  Is it my lack of practice or could there be something about the machine causing this?  I know moisture on the rod will make for a less than perfect weld, but could it cause this problem?  I've been at it two days now researching and trying every thing I can think of and loosing my mind.  Please help!!!
Reply:The same thing happens to me. I tried again today at 135 and 150 amps and does the same exact thing you described. I got my rods second hand and are probably 20 years old thats what I thought the problem was. they have always been stored air tight. I just ended up running a bead the best I can then going back over with a smoother arcing rod to make it pretty. Would like to find out if its user error aswell. I dont want to try buying new ones till I figure it out now that I know other people are having the same problem.
Reply:I'm glad to not be the only one as well.  I put a few rods in the oven for about 1 1/2 hours and it seems to help a hair.  I'm gonna leave them longer and try another.  If anyone has any other input I'd greatly appreciate it!
Reply:What brand of 7018 you trying to use?I've ran a few jobber (no name brand) 7018's and they were lousy to run.3/32 rod might run better than 1/8 rod on your machine also.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:I don't know the brand of the first ones, the new ones are radnor.  After 4+ hours in the oven at over 400F they're still the same so I doubt it's a moisture issue.  I'm just going to go buy some different rods because I really need to get this done.  I tried a 3/32 also and it wouldn't even start, but those weren't labeled as AC so it's no surprise.  I'm probably just going to buy some 5/32" 7014 and get as much penetration as they'll allow.  The 1/8" 7014 I tried wasn't doing too well, but the one 5/32" rod I had left seemed to work ok.
Reply:It's not unusual for 7018 to burn up inside the flux shell. It is a contact (drag) rod tho so it's normal to feel the flux crumble if you're leaning on it a little. That flux should burn off better as you go tho so it could be that if you're trying to run low for the thin metal then that 3/32nds might be a better choice as mentioned. No surprise if when you stop a bead your rod is back up inside a bit each time. A quick crumble with your gloved fingers or a drag on an old coarse file helps for restarts. I was never big on tapping it on the work piece altho that works."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Are you sure it's 7018AC?What you'r describing is classic attempting to run regular 7018 that requires DC on an AC machine - which both of you have.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Replyefinite AC rod, marked on the box and the rod.  I've tried amperages from 80 all the way to 200, my machine's max.  The melt speed changes, but the rod still melts way faster than the flux.  Below about 100 it's nearly impossible to get it started.  I tried pushing instead of dragging and it helps burn the flux a little, but still has to be pushed into the metal hard and starts gouging out a trough even at lower power.
Reply:I've used on 3/32 Lincoln 7018 AC on:- a small 80 amps AC transformer welder,- an 40 - 140 amp AC/DC welder - use them AC. DC+ and even DC-, no such flux problem- an 80 amp DC inverter welder - used them DC+, perfect.Lincoln 3/32 7018AC works for me.Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:ESAB atom arc 7018AC is another very solid performer for this catagory of electrode.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Been welding 30 years burnt all kinds of brands of 7018 never seen that happen. Finger nail ok but not just stop
Reply:I'm a bit rusty with the stick, been migging for a long time.  I think my welder may be jacked up.  I used some 6011 and 7014 of different diameters and different amperages and none are flowing like I expected.  Even the super easy 7014 was splattery and not laying down right.  I'll play with it more in the AM.  THANKS to all!
Reply:What sort of machine is it? AC only? If it hasn't been used in all that time either, it may need a tune up and oil change. That's a joke... But, it might need to be checked out. Crack the case and blow the cobwebs out and go from there, huh?City of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:AC rod should run a wee bit different from DC rod.With DC rod you bury it in the metal.AC rod runs well with a little standoff, maybe 1/8 inch.  But be aware that excessive standoff can result in porosity bigtime.Push it in there until the arc drowns, then pull it back until you hear a "snappy" hot sound and the arc digs.1/8 runs very well at 135amps in the AC mode when it's an AC rodEven though the rod has burned well within the flux coating (looks as if the rod is up inside a core), the restrike is almost instantaneous."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Have you checked all the cables and work clamp connections? Simple stuff, but poor connections won't work. Possible corrosion under terminations from sitting around?
Reply:7018 AC rod is not a very nice rod when compared to the good ole DC. My first welder was a AC welder and I remember trying to learn with AC 7018, It almost made me wanna give up, lol. The DC stuff is just smooth as butter.
Reply:Originally Posted by farmersammAC rod should run a wee bit different from DC rod.With DC rod you bury it in the metal.AC rod runs well with a little standoff, maybe 1/8 inch.  But be aware that excessive standoff can result in porosity bigtime.Push it in there until the arc drowns, then pull it back until you hear a "snappy" hot sound and the arc digs.1/8 runs very well at 135amps in the AC mode when it's an AC rodEven though the rod has burned well within the flux coating (looks as if the rod is up inside a core), the restrike is almost instantaneous.
Reply:With a stick electrode on a constant current machine, remember that even though the current is fairly constant, the voltage and thus the power or heat will vary with the arc length. If you need more heat to melt the the end of the flux faster and to put more heat into the weld, greater length might be needed. Sam is correct about porosity, but didn't mention that rod angle will influence this somewhat too.
Reply:Good call on connections--Initially I did have some bad connections at both cables, fixed that after a noticing they were getting real hot fast, welds got a bit better.  The machine has been sitting, will give it a 100K tune-up.  Hadn't really thought about it, but there may be some corrosion inside.  The spark plugs (rods) are new but misfiring; may need a new cap & rotor  It won't carry a distant arc with any of the rods I've tried no matter how much I crank it up, further thought that it's the machine.  So far I have used 6011, 7014, 7018 from 3/32 to 5/32 and none burn right.  I have over powered all of those rods and none blow away like I'd expect.  Tho I'm rusty at it, the first time I welded was when I was about 10 and it took all of 5 minutes to make it work.  I've welded off & on ever since and have never needed more than a couple warm-ups to get a decent burn.  Hhmmm, that first time was probably with this same machine, 30 years ago.....That tune-up is sounding more like a good idea.  As for the 7018 in question-It tries to stick initially, once I get it started I have to bury it HARD to keep it burning and it does poorly.  I'll tear down the machine and retry.  The first welds I finished yesterday weren't overly critical, tho I'd have liked better ones.  The next round is for the suspension hangers and spring equalizers, I want those right!
Reply:I live in N.C. in a tropical area-it's humid all the time. I have problems with porosity at home with my a/c stick welder. I have used nib Lincoln a/c rods and Hobart a/c rods.same problems. I know on the back of the lincoln box it read something like: prebake at 700~F for one hour and then store at 250~F...I don't think a lesser temp. for a longer period of time gives the same effect. BUT if I take them to work and run them on our  big Linde, Lincoln, or Miller ac/ dc machines they work fine. The bigge4r machines give a more stable arc??
Reply:I opened up the machine and ran a few beads, all connections stayed cool and it was pretty clean inside overall.  The ground clamp was still getting a little hot so I replaced the cable lug and it seems to weld a little better with 6011, still the same flux problem with the 7018s tho.
Reply:If it were a larger commercial machine, I'd say check that it is set up for the proper voltage.If it were DC, than a bad rectifier maybe. All I can think of right now is that the wiring to the outlet could have high resistance, if the machine seems to be OK. You might try checking voltage at the input while operating the machine, and then check both open circuit voltage, and arc voltage, to see if it tells you anything.
Reply:Thank you all for all your help!!!  I couldn't see using 7014 for the more critical suspension parts I'm building so I decided to try some 3/32" instead of 1/8" 7018 so I could overpower it and it's working.  By the machine's settings I'm using about 110 amps for most welds, and 125 for the lap welds.  I can't run a full stick without it turning red all the way to the stinger, one actually melted off before running out.  I recall something about lap welds absorbing heat more rapidly, don't know if that's true, but it seems to be.  Even with the smaller rod I have some flux issues, but they're mostly manageable and the welds appear to be good.  If they're not I'll have a road-scarred 30' Scarab for sale soon    Thank you all again~Oscar.