Thread: Electrode for DC stick welding an I beam

It sounds like for your app you could just strap the joint as you described. When I welded in my I beams I used 6010 root, 7018 top. If you can buy a lb or two of each at the local welding shop then go for it.

If you have the beam down on the ground, have you considered welding the beam with 6013 and then strapping as you described? I don't think a couple hundred lbs will hurt that weld.

6010 burns a little smoother than 6011. (rod +)
7018AC will typically trap more hydrogen than the 7018 rod. (rod+)

Just about any rod will run better on DC.
7018 is a real pain in the butt to get the hang of. I remeber sticking, sticking, and more sticking. Striking it like a match, then poking it quick...

If you take the time to learn 7018, everything else will be easier.

not for nothing, but I bet you could pick up a 4' length of that I beam (S4x12,perhaps?) for less than you'd spend on two boxes of welding rod...


I think I'm out of 60xx but if you wanted to try a few 7018 rods I'd gladly send em out to you.

Yeah, I think I could pick up a beam for less than two boxes of rod. :rolleyes:
Ater all this discussion though I want to go ahead and see how it goes.
I'll message you my address
Thanks
Dave Lawrence

Lalatheman, yes there is 7018 and 7018AC. The difference is in the flux, not the filler metal. In AC welding the arc starts and stops 120 times per second, so you are constantly having to restablish your arc. The fluxes used in AC rods are especially designed to maintain a a gaseous plasma that makes it easier to restart the arc. The 7018AC rods are also made to work better with the low open circuit voltages typically encountered with your home workshop type AC buzzboxes.

I still don't see the point in using a 6010 for a root pass then capping with a 7018. As we all know, the first two digits represent the tensile strength of an electrode. Assuming that we are talking about a conventional mild steel I beam, 30,000# tensile strength, what good does it serve to have a 70,000# cover pass? If properly done, any electrode in the 60,000# tensile strength family will work. It's stronger than the parent metal. The 7018 was designed for "crack sensitive steel", hence the idea of reducing the hydrogen in the weld puddle. I have made up beams(for moving) as much as 94', by butt welding (veed out of course) several pieces together to get the length. The only time we used 7018's was in narrowing axles for dollies or on high tensile channel beams, both of which would fall in the catergory of "crack sensitive steel". As to the 6010 running smoother than the 6011, I suppose that boils down to personal interpretation. Personally, I feel it's just the opposite, but, that's my opinion. And yes, talk to some of the "old guys" with Lincoln or Hobart, not the young college kids, and they will tell you the 6011 was designed for the AC machine, basically an equivalent to the 6010.

You cannot assume the weld will be a uniform 60k. It will be weaker on the edges, arc starts and stops, etc.

2:1 overrating should be reasonable though, I cannot see a problem putting a 4-500 lb load on a 4' long S12 beam with an all 60xx weld.


6010 inner / 7018 outer is a well accepted pipline weld procedure. 6010 will freeze somewhat fast and prevent joint drip through. 7018 gives a very solid bond, good penetration, etc and it builds up nicely on the 6010 base.

YMMV!

I don't see anything wrong with a 7018 cover pass and know a number of weldors that do that. I suppose that I should say that my difference is based on "a chain is no stronger than its' weakest link". Hence, mild steel being approx. 30,000 TS. While the cross section strength of the weld may vary somewhat, I should think that the 60xx would have ample margin for such a variance in tensile strength. I remember doing quite a number of guided bend tests over the years and always found the 60xx to "hang with it". The 7018 is "user friendly" once the operating characteristics are understood, and is an excellent electrode in its' own right.

That having been said, I would hope that these posts are viewed as part of a "spirited debate" and not as personal attacks. My apologies to anyone who might have been offended.

John

I think one of the advangates of a 7018 cover pass is that it is easier to get a 7018 pass to look better than a 6010 or 6011 rod.

I agree that 6011 is AC and 6010 is DC. You can run 6011 w/DC , but I have found that 6010 runs a little smoother.

Just to clarify, no issues here.

can't have issues with what sounds like a bunch of very knowledgable people.
particularly the term "weldor"....been a long time since school and that one had drifted off into "oldtimers syndrome"...
one thing this discussion did for me is remind me why i dropped that stick the second i got a scissor lift big enough to stuff my 300 lb lincoln mig outfit in and still have room to hang out the railing and make sparks..
.
"anything from the crack of dawn to a broken heart"
.
of all the crap i gotta do everyday watchin' that bubble still makes me smile

LOL! [img]smile.gif[/img] , I didn't think I was an "oldtimer" but I guess I am after all ! No offense taken. Guess we all wind up being one if we live long enough !
I, like most here, started out before, or just after(possibly), the advent of MIG, and I remember Miller had a lot of problems at first, with the wire "birdnesting". But it was sure the "rage", especially on sheet metal. Bad as we may hate to admit it, it sure is nice to not have to stop and chip, etc. I prefer MIG on new metal and still favor the arc for general repair on rusted/painted metal. And, it makes "tacking" a whole lot easier and precise. Come to think of it, does anyone know when MIG was first developed? Not wide spread commercially, but rather the first prototype machines ??

Thanks,
John

The first patented MIG system seems to be the mid 1920's, but the first functioning unit is generally thought to be 1949, with commercial units, albeit big and clunky, available in the 50's.
http://www.netwelding.com/History_MIG%201.htm

But even though it was a proven technology, it was expensive and scarce through the early 60's.

p5 and 7018 are great rods but u have to watch the 7018 so they dont get damp, keep them dry and warm, also if u have flux pockets on 7018 u need to practice a lot more


6012= farmer rod heheh
1/4 7024 = a long day at it

I got the 7018 today, (thank you much damonfg)
and begain practice welding on a non critical piece , support members for a wheeled welding table. I was making the root pass 6011 and covering with 7018 .
I see what several of you guys were saying about slag inclusions, and yes so far they are there.

Kind of really enjoyed using rod again, although I do mig and tig now, nostalgia perhaps. I don't think rod will ever go away, and I would like to maintain and further my ability in that specialty. There are lots of younger people growing up now that will weld but probably never learn stick. OH well time marches on ...
I'm not convinced I like marching though :rolleyes:
Dave

Enjoy the rod [img]smile.gif[/img]

What kind of slag inclusions are you getting on 7018? Along the sides of the bead or in the buddle area?

I'm getting both. By carefull chipping I can get the side inclusions off.

After chipping off the puddle area it seemed like grinding was the only way to get it clean, when i ground down it seemed like there were also about 3 small apperently empty bubble holes entraned in the bead in the general area ot the puddle slag pit.

Dave

Increase the current and it should flow better on the sides. Perhaps a little more action with the arc will float out the smaller inclusions in the puddle. A figure 8 may help, maybe a up-forward-back-down-forward-back may help with both inclusion types.

Yeah current, common mistake is to not use enough of it. Dont STARVE the weld!

Here is possibly an example of what you are attempting to do.

In my case this is an S4 x 7.7 I-beam which I needed to splice.

I MiG welded it with a Miller 251, back beveled all surfaces and did the work in the horizontal position, tacking and turning before the final passes.

2 x 2 x 1/4" angle iron "strongback" helps to increase stiffness in that section. I have seen diamond shaped patches applied to both sides of the web. Anything welded to the bottom of the beam...be careful as it may interfere with the trolley operation...

-Matt

LA, are you running rod negative? That will help too.

Are you suggesting to run the rod neg? I ask because running the rod neg. results in less penetration and therefore possibly a weaker weld, right?

Rod + puts more heat in the rod, faster dep rates.
Rod - gets more heat into the work.

Conventionally, if all is ideal, 7018 should run rod +.


As to weaker, if you have less penetration turn up the welder. If the joint is welded with proper penetration, then it will be of suitable strength regardless of DCEP or DCEN (or even AC!)