First time with 7018 ac

[bigtiller]

I opened a box of 7018ac and used it for the first time ever. I started the weld with 7014 on my boom pole lifting point and planed to cover it with 7018. I got about half way through the rod when it quit welding. I couldn't get it to start again. I scratched it on the table and got no or very little sparks. I moved the ground and nothing happened.

Finally I went back to 7014 and finished the weld. What's going on?

I'm not a weldor and here is proof.

 

[oldnslo]

Is 7018 the rod that will burn up inside the flux coating and potentially cause the arc to stop? It has been a lot of years since I used any so going off of a feeble memory.

 

[Gary Fowler]

7018 is an iron powder coated electrode and if you break the arc the flux will seal over the end of the rod. You rarely will be able to scratch start it again, you instead have to strike it rather hard on the weldment to crack the flux off OR tap it with a piece of steel. I have never had one that you couldn't restart by just tapping it hard on the steel again. Many times it will stick when doing this and have to take it out of the rod holder to break it off.

 

[bigtiller]

Thanks Gary. I am certain (i think) I can remember to do that next time.

I was anxious to try out the 7018 yesterday and disappointed at having to do my second pass with 7014 again so I could finish that project.

oldnslo, That made sense to me so I went out to look at the rods. The 14 & 18 rods were burnt down equally. It seams Gary learned me something and remembered you something. Hopefully we can keep it on file for awhile.

 

[RNeumann]

7018 Re-Strike Techniques Explained - YouTube

The 7018ac may make things worse- I’ve never used AC so I don’t know for sure.

 

[bikerdib]

You already have been told what is going on so I won't say any more except that in my experience when you have to hit the rod hard to restart, lots of times the flux will be knocked off 1/4 to 1/2 inch of the end also. Just be aware that it won't weld very well when first restarting because of this.

I still run 7018 AC rods on DC because there is less splatter.

One last comment, IMO you are doing the welds in reverse. If I were doing it, I'd do the first welds with 7018 then if you need to, cover with 7014. That should give a stronger connection. 7014 is generally considered a fast fill rod used when the joint needs to be closed but not necessarily structural.

 

[bigtiller]

When it blows out, can i chop 1/2" off in the abrasive chopsaw and start welding again?

 

[BukitCase]

If you're gentle about it - otherwise it tends to just break flux further back if you put too much down pressure on the saw. I always had better luck just immediately pinching the end off (heavy weld gloves, of course) then as Gary said, do a FIRM version of the "strike a match" move - once you see a spark, you're good to go again... Steve

 

[bigtiller]

Thanks BC, another great tip.

 

[bigdeano]

How many amps are you running, and what size rod? Looks to me like you need more current. Get down close so you can see what's happening with the weld and move along smoothly like you're a machine. With a little practice your welds should look great.