Trouble with trapped slag on hotpass

Date 01-11-2017 16:08 Edited 01-11-2017 16:43

As for the slag, is the slag remnants of slag at the toes of the root bead deposited with E6010? If so, more grinding or better technique to prevent the convex bead that trapping the slag to begin with. If the slag is from the E7018, you might be running a little too low on the current and again, trapping slag along the toes of the weld. If the slag is between the second bead and the first, it is technique. Reduce your arc length may help. E7018 runs best when a short arc length is maintained.

Tough to really know what you are doing without watching you or seeing a photograph of the problem.

Keep burning wire, that’s the only way to learn to weld.

By welderbrent (*****)

Date 01-11-2017 16:53

That's cheating Al, while I was typing you removed that possibly misunderstood comment. I thought it was good lesson material.

Brent

By Wilburjc Date 01-11-2017 17:00

Haha, did I sound like a dumb ass? I figured. But I appreciate your reply! The slag is being deposited at the toe of my hot pass (E7018) it generally gets trapped along the right "toe" of my bead. When you say I may be running too low on current, are you referring to amps or arc control? I generally maintain a fairly good angle. I have been trying to keep my rod up close to the metal to the point where I can hardly see ahead of my puddle due to lack of light. Again, your reply is much appreciated!

By Wilburjc Date 01-24-2017 01:25

Al, what was the book you suggested I get?

By 803056

Date 01-24-2017 01:44

I recommend a copy of AWS A3.0 Terms and Definitions for one. For technique; Lincolns Welding Procedure Handbook. I have a copy in my office somewhere. It provides some direction on the parameters for different electrodes and processes. Fair warning, for the most part Lincoln is an advocate of weave bead technique which is fine for most constructional steels. If one is welding Thermomechanically enhanced steels or quench and tempered steels, stringer beads is probably better for maintaining low heat input to minimize the degradation of the mechanical properties in the HAZ.

Best regards - Al

By welderbrent (*****)

Date 01-11-2017 16:52

Wilburjc,

WELCOME TO THE ORIGINAL AWS WELDING FORUM!!

First, don't misinterpret Al's post, he absolutely DID NOT call you a dumbass or say we thought you were one...LOL.

But, there are a lot of misused, industry specific, non-standard terminology that can make you look like an uneducated fool in many circles. Yes, you used some.

Before we just tell you, try to think about what you said compared to what you may already have learned.

Other than that, 3G can be a little tricky when first learning. One major mistake is to try and run it with the amps to low. For 1/8" 7018 keep it up there, 110-130 with 110-120 for thinner plates. Can be even higher but this is a good start. And of course, this will depend upon machine calibration and actual gauge reading to produced amps at the electrode ratio.

Next would be possible technique and especially if you are pulling too far ahead of the weld pool while moving from side to side in the groove. Move quickly across the center but not so quick you pull out of the weld pool. Also, make sure you hold plenty long on the sides to 'burn out' the slag there.

Also, as Al mentioned, is your arc length. If you are carrying enough amperage, you should be able to practically 'drag' the electrode and feel the coating scraping on the edges of the plates and the existing weld pool. Keep that arc short. If you do not have the amps high enough then that is why you get the electrode 'stuck' to the plate when you do get down close. Low amps will also contribute to getting that electrode stuck way too many times when striking the initial arc.

Now, if it is slag in the 6010 root, you may be trying to carry too large of a root pass, moving too far ahead of your weld pool by 'whipping' with too long of a stroke, or running too low of amperage and getting slag trapped along the edge from one of several possible conditions such as overlap.

Good Luck.

He Is In Control, Have a Great Day, Brent

By Wilburjc Date 01-11-2017 17:13

No harm no foul! I'd rather be called a dumb ass by people who are trying to help me, than have a foreman call me a dumb ass. Lol

I bet you I need to turn up my power! I've been running the root at 87 amps, and my hot pass at 100-102 amps. I always ran low amps because when I first started 3G I would long arc, and either have severe arc blow, or I would completely blow through. I don't struggle so much with long arcing anymore so I reckon I should crank it up some! Thank you!

By welderbrent (*****)

Date 01-11-2017 17:28

Remember, Al and I are older than dirt though welding was developed after we were born....well, okay, that may be stretching it for me .

So, we are used to running higher amps than would many a new comer. In fact, I used to run so hot it took a good CWI some serious time and effort to get me to turn my amps down. I was wasting 3" of electrode because it got so hot by the time I got down to the end that the flux would be glowing and not work as shielding. Beads looked good and always tested good but it is a bad habit to get into for most applications. Heat input and the HAZ can be a bit of an issue even when it isn't a critical aspect of what you are working on.

Having said all of that, yes, I would say your amps are too low. Try going up to 100 first. Then work your way up from there.

Brent

By 803056

Date 01-11-2017 17:40 Edited 01-11-2017 17:46

87 amps with 1/8 diameter E7018 sound mighty low.

A common misconception is that a successive weld bead will "burn out" any slag left in the preceding bead. That thinking is what keeps NDE people gainfully employed and weld joints have to be repaired and reexamined time after time.

I was actually throwing a stone at the welding instructor! Has he told you to preheat the base metal to drive the moisture out of the steel before welding or that low hydrogen electrodes run better if they are quickly dipped in water? Just because the instructor thinks he has a golden arm doesn't mean he doesn't need to crack open an up to date textbook now and again. The terminology used in your post has no place in the classroom. If the instructor taught a science course, he would tell the students the planets orbited the earth and the earth was flat. Good thing he doesn't teach science or all of his students would have to turn to politics to earn a living. Our taxes can only support so many politicians and I think we already have too many dumbasses moving to Washington this year.

As I mentioned in a different Forum, welding instructors often score poorly on the CWI examination because they figure they already know the material. I had welding instructor tell me, "Al, what I've learn in the last few days is that I know nothing about welding and I've been teaching my student the wrong information for the last 15 years." Sad to say, he was right. The good point was that he did learn and he passed the examinations. Point being; it is possible to teach an old dog new tricks.

Good luck with your endeavor. Do yourself a favor and buy a copy of the Welding Inspection Handbook from AWS. You might find a recent edition on Ebay or Amazon. Speaking of which, now that my wife is almost out of the woods medically speaking, I need to get back to my commitment to revise a couple of chapters for the next release.

Al :grin:

By pipewelder_1999 (****)

Date 01-19-2017 16:43

I think there are a couple of things contributing to your difficulties.

1) In real life, the joint design you describe is a challenge for anyone with the method you describe. Not impossible, but difficult. A typical open root prep for a 6010 root pass would almost always have an included angle of 60 Degrees Minimum. A change in weld prep could help but I understand this may be a fixed setup that is always used...WHY who knows.

2) The issue with slag on the pass placed over the root which in many circles is referred to as the hot pass is probably NOT because of slag but more the result of convexity on the bead. In many "real life" operations, the 2nd pass would be deposited with an XX10 electrode and NOT a 7018. The 2nd pass would have a much flatter profile AND the width of the face of the weld would be wider and therefore better facilitate getting the big ole 1/8" 7018 in the joint with a nice tight arc and also room for manipulation.

If all of the slag were removed from the toes of the 2nd pass bead, defects would probably still occur if the profile were still convex.

Reducing the convexity would result in reducing the discontinuities along the toes. Because of the difficulties associated with the joint you describe, a wider 2nd bead with more pause on the sides and less time in the middle may help. An adjustment of amperage can sometimes help and I have found a sweet spot for 7018 to be in the 110 range and anything much below 105 gives me issues unless welding on lighter material

3) 1/8" E7018 can be a challenge for many when the conditions are ideal. The settings, arc length, and manipulation all play a key part in what happens. I am assuming you have already welded a plate on backing. If it were fitup like typical joints of that type, then there is plenty of room to manipulate the electrode as shown in the image attached. Because of the conditions, all of the things that work to correct convexity as you learned to weld with 7018 are now more critical.

I have not walked in your shoes or those of your instructor so what you are doing may have a purpose. All variables in a given weld work together. Amperage, Voltage(Arc Length), Travel Speed, Manipulation, Groove Angle, Root Opening, Root Face, Preheat, etc.. Changing one will always change the results unless something else is changed along with it.

Attachment: Drawing1.jpg (522k)

By pipewelder_1999 (****)

Date 01-23-2017 16:14

Turn it up for the overhead.

Its just like flat but harder on your neck and of course when the slag peels off in one big piece, it may fall on you :)

By Tommyjoking (****)

Date 01-30-2017 00:42 Edited 02-01-2017 02:11

Good for you Wilburjc I posted all this junk without reading all the way....happens with us old folks sometimes.   Good for you man and your just one step away from a lohy 6g ....not much diff in myho. if your crawling uphill clean you can do the same from 7-3 o-clock on a pipe. im kinda an old timer and I will tell ya I struggled with lohy more then anything else. Leave this post here cause maybe ...maybe it might help someone.

dont worry with being to hot.....most folks learn lohy and tend to be cold....don't know if that is you or not.

weld hot and WET   start just off the side and go UP for middle of joint then go back down opposite side and repeat.....that action will be become more apparent once you cross 7-8 o clock on the pipe. WELL heck your not welding on pipe yet....not much difference. Light your rod up in the middle, let it burn for half a second then drop down to one side, pause for a very quick second then, ARC UP (round motion) over to the middle, and back down to the side (toe) of the weld. Hang out for a half second and REPEAT.....if you spend to much time in the middle or going side to side it will pile up on you. DO not weld so cold the puddle stays put....you need to be hot enough if you do not move it goes bad fast. Make moving that rod a count in your head like a dance....1-2-3, 1-2-3, 1-2-3........ After a few plates you will find it easy. I suggest capping on a bare plate...easy for practice... no prep. Once that cap is easy to you, you should not have a problem putting clean filler in the bevels.

Capping bare plate get it looking like you want, and clean. If you have undercut on toes (sides) then that means you did not drop down far enough OR hang out quite long enough on sides.

There are many ways to manipulate that 7018 and shoot clean, above is just one way. The most important thing is YOU get comfortable.   Trust me just make a rhythm in your head and follow it....it will become second nature to you.

BTW usually as long as the puddle is still liquid you can step in or out.....the flux cannot be trapped as it will rise to the top of pool.   If the metal is liquid so is the flux covering it ....that is true for about every material.

Tommy

By Superflux (****)

Date 02-04-2017 04:19 Edited 02-04-2017 04:26

Keep up the hard work and don't let the small details haunt you. It's frustrating, trust me. We all go through it even after we know it all. If there is a consistent problem on the right side with the slag entrapment, I think it might be an angle of the rod problem. Perhaps your wrist needs to rotate towards the offending weld toe.

By Tommyjoking (****)

Date 02-13-2017 02:33 Edited 02-13-2017 02:36

I agree with more heat for overhead//// it has always worked for me.. downhill Pipe hands have told me they turn it down for overhead....I think different rod different action. I go about 5 amps hotter or so for overhead bevels ....weird thing is i push to....about 5 or so degrees push on a 7018 overhead. Not saying it will work for you but I have passed somewhere around 25-35 3g+4g unlimited tests using that same stupid technique. Clean is clean...bust is bust.

BTW. CONGRATULATIONS on conquering that uphill bestie