Page 1 of 1

7018 Excalibur Slag hard (very hard) to get off

Posted: Sat Jun 29, 2013 3:33 pm
by ldbtx
I watched Jody's video testing Lincoln Excalibur 7018 and really liked the way the slag pretty much crawled off the weld and jumped in the trash all by itself <G>. So, I bought some of the rod to practice and "get my hand back" since I've been MIGging exclusively for the last several years. Over the course of a few hours today, the touch is returning and the welds are looking much better than they did this morning.

But the slag isn't cooperating at all. I'm having to tap on it pretty hard to get it to come off the weld. It's not curling up by itself and raking generally won't do it. I've been welding some horizontal fillets and some vertical up fillets -- same result either weld. I'm running between 100-125 amps, DCEP with my Bobcat 225. Probably should mention that the rods were not in a oven when I got 'em at the local welding shop.

Any ideas what I might be doing wrong?

Thanks,
ldb

Re: 7018 Excalibur Slag hard (very hard) to get off

Posted: Sat Jun 29, 2013 5:37 pm
by Otto Nobedder
This usually suggests you aren't holding on the edges of the weld quite long enough, and leaving a bit of undercut. The slag will lock into this tight, and be a bitch to remove. This can happen across the middle of the weld if you're too cold, as well, and have excessive ripples along the weld profile.

A picture of a cleaned weld would help a lot.

Steve S

Re: 7018 Excalibur Slag hard (very hard) to get off

Posted: Sat Jun 29, 2013 6:20 pm
by GWD
Is your metal sparkling clean? Grind it to shining and see if that helps.

Also, consider Steve's (Otto) suggestions.

I'd be tempted to run it a bit hotter than what you described if it is 1/8" rod. The original post doesn't mention the size. That is vital information if the amps are to make sense.

Re: 7018 Excalibur Slag hard (very hard) to get off

Posted: Sat Jun 29, 2013 6:55 pm
by Alexa
Idbtx.

Just to understand better that rod and slag, run some single passes on a flat plate. Start with a very low amperage pass, then gradually increase the amperage for each pass, until you a running excessively hot. Make a note of the difference of the slag peels off as related to your amperage. Also note the quality of the weld appearance.

Slag is one of the many variables of 'weldability' of a filler.

Alexa

Re: 7018 Excalibur Slag hard (very hard) to get off

Posted: Sat Jun 29, 2013 10:25 pm
by ldbtx
It's 1/8" rod, GWD. Sorry I forgot to mention that little vital bit of info. No, I didn't grind the stock to shiny, I just used a twisted cup brush in the angle grinder. It was clean but not sparkling shiny clean. No loose scale or anything on it.

I think Steve may be onto something, since the slag loosened up a bit as my welds started looking better as I burned more rod after I made my post. My edges were getting better as the day progressed.

I'll go out tomorrow, crank the heat up a bit, grind it clean and see what happens. Also, going to follow Alexa's suggestion and run the series at different amperages. That should be a good source of info, especially considering it's a brand new welder.

Thanks to all of you. I'll let you know how tomorrow turns out.

ldb

Re: 7018 Excalibur Slag hard (very hard) to get off

Posted: Sat Jun 29, 2013 10:30 pm
by GWD
ldbtx wrote:It's 1/8" rod, GWD. Sorry I forgot to mention that little vital bit of info. No, I didn't grind the stock to shiny, I just used a twisted cup brush in the angle grinder. It was clean but not sparkling shiny clean. No loose scale or anything on it.

I think Steve may be onto something, since the slag loosened up a bit as my welds started looking better as I burned more rod after I made my post. My edges were getting better as the day progressed.

I'll go out tomorrow, crank the heat up a bit, grind it clean and see what happens. Also, going to follow Alexa's suggestion and run the series at different amperages. That should be a good source of info, especially considering it's a brand new welder.

Thanks to all of you. I'll let you know how tomorrow turns out.

ldb
Excellent plan. Be sure to report back. And photos if you have them.

Re: 7018 Excalibur Slag hard (very hard) to get off

Posted: Sun Jun 30, 2013 3:05 pm
by Otto Nobedder
Idbtx,

Now that I know it's 1/8" 7018, I'll add that the Amp range your working in is ideal for most of us, assuming the amp setting on your machine is accurate within a few percent. I only run above 115 in a 1G position.

For pipe welding, I almost always use 105A, because I learned the "bury-rod" technique for 6010 root, and I can do both root and cap with 1/8 rod at 105A, and not have to keep changing the machine.

For a vertical fillet, though, I like 115A. This is hot enough for good penetration, and to fill the toes to avoid undercut, but not so hot that I have to hurry myself.

For some reason, slag likes to hang on tighter in a fillet that a groove weld, so have patience with yourself. I rarely have slag "peel" in a fillet, and am quite satisfied when raking it gets the job done.

Steve S

Re: 7018 Excalibur Slag hard (very hard) to get off

Posted: Sun Jun 30, 2013 5:35 pm
by ldbtx
Thanks for the additional info, especially from your working experience, Steve.

No welding for me today. Had to work on the well pump...but it's worth it to live in the country. Thanks to all of you for the input and guidance thus far. I'll get back to burning some rod, and keep y'all posted. Thanks again.

ldb

Re: 7018 Excalibur Slag hard (very hard) to get off

Posted: Thu Aug 15, 2013 11:33 pm
by ldbtx
Haven't been able to burn as much rod as I'd like to. Been real busy at work. But thanks in large part to the good tips from y'all here, what I have been able to weld has shed its slag a lot easier. Got the current dialed in and paying better attention to my puddle. Life is good. Feels like I'm coming back after so long away from stick welding. Thanks y'all.