farm guys figured this out a long long time ago, no prep at all just lay it on the rust/paint/grease and it'll be fine as long as you say "that aint going nowhere" once it's done 😂
Much as if your first run is with 6011/6010 - you get as much of the slag off as you can - then do one or more passes with 7018, again cleaning as much as you can in the shed/barn/whatever Warren called his big place where they worked on equipment. A large dairy farm which has its own haulage has a lot of such equipment. Warren said he had a 1500 hundred head herd.
I used to repair oil production equipment. A lot of it came from Texas. We used to say, "There's only two slag hammers in all of Texas and the welders take turns using them. If it's not your day to use a slag hammer, you don't have to clean your welds."
I tried it once many years ago and got similar results. What I think makes removing it between passes more important is proper placement of subsequent passes. It's hard to judge with all that crap in the way, imo.
I used to see farmers going over 6011 or 7011 without cleaning and the welds always held, they used to use the same rod to cut with outs in the field, crank a 5/32 rod to the highest amp the machine would go to and blow through what they needed to cut!
My dad taught me to weld and braze with ox/acetylene and with SMAW when I was eight years old. I never had clean metal to weld until I started TIG on aluminum 20 years later.
Thank you so much for showing this. I saw "IC weld" spotwelding like stacking dimes without cleaning. It was thin material and he made sure, to penetrate and not to burn through. I would never question this man, but i asked myself, why he was so confident. Now i know.
Without a doubt 7018 and dual shield will weld through slag. I don’t make a habit of it, but it is reassuring to know that it isn’t a guaranteed slag inclusion and weak weld 😀
That is neat to see. I have often thought the first pass flux would be melted by the second pass, but probably not a good thing to do. Thanks for trying and sharing.
It worked in this instance, but with many rods (like 6013) the results will likely be far different. It definitely pays to clean between passes, it’s easy and is only a benefit lol.
@@makingmistakeswithgreg I am reminded of arc welders that were self propelled along weld and had a hopper of flux 'pellets' that were deposited over the welding arc, and a real of weld wire. The excess could be swept up and presumably re-used, and the melted had to be cleaned off the weld. I think a fair bit sort of self detached. Only ever saw them in film, not in person.
LH rod's no but crap conditions and 6011 you bet, lost track of how many times I had to sneak a rod sticking straight out, stinger, arm snaking in between other objects just to lay several beads on a repair job. surface prep/chipping ect. wasn't happening, even after air-arcing, gouge and weld. An X-ray would be interesting to see how much slag inclusion there was if any. cool experiment 👍🏻ty.
Nice video Greg. I’ve heard of old timers that claimed they could weld over slag and still produce clean welds. I’m sure it’s a struggle to actually burn through and still get the weld placement where you want it. I was pretty shocked with how clean the etch was. You’re one of the only ppl on here with this video subject. I tried looking this topic up just to see if the “hot pass” over slag ppl were blowin smoke, or if it could really be done
My thought is that this seems like something that might be worth teaching to people where "fast & good-enough" (in that order) is the name of the game, like shipboard damage control teams where you might not have the time to do it right. Thought what might be even better is to formulate a flux that tends to "self remove" enough while cooling that just a swipe or two with a brush will clean most of it off. What might be more interesting would be a test with just doing a "lazy clean": a wack or two with a slag hammer and brush off whatever that knocks loose and call it ready for another bead.
It's one of those things that works sometimes - like when you're working on very small parts that stay at 800 degrees and doing an in position weld - and then people think it's perfectly fine everywhere because they've never had a problem since. Then a bridge almost collapses because someone left a massive slag inclusion inside a weld, and it gets fixed and everybody forgets about it and goes back to doing shoddy work. It's a good thing to test though, and I appreciate you saying it's a bad idea. Be neat to see you break it too.
You’re definitely right. It worked on a simple flat fillet weld that got hot, and i was running rods at 130a or so. Do it over some cold slag, with less amperage and skill, and the weld produced will be stupidly weak lol.
Surprised by that result. The best way l have found for cleaning slag off a weld and in particular multi pass welds is with a needle scaler. The needle scaler also has a peining effect on the weld to stress relieve the material. You can see the tiny dents on the weld surface when you look closely at the shiny weld bead as you inspect it before the next pass. All interesting stuff young man!
Hey Greg, thanks for another excellent video! My welding instructor claimed that it is possible to "burn through" or "burn out" slag with basic electrodes but not so much with rutile electrodes. I have nowhere near enough experience to judge whether he's right or not, but it may be worth taking into consideration.
I know that 6013 would probably not melt through the slag. I expected 7018 to perform more like 6013 but it surprisingly didnt. For fun I will have to test out some other rods, I know atleast a few will give terrible results lol.
@@makingmistakeswithgregfirst thing I thought when you mentioned 7018, why not 6011? 7018 "moves slag off" easily, so yeah I think maybe a different result with 6011, would be awesome for some more tests !
interesting ! I've always heard that your supposed to clean and wire brush between passes but on the Ranch I had a brace brake on the bush hog and I was in a hurry.. so I welded up the brace without any prep at all welding through the paint and some rust the weld is strong to this day.... so I figured the weld would penetrate through the slag on top and that is exactly what it did , this is good to know ! clean it if you can... if you can't weld it anyway it will still hold if you watch the puddles close keep them connected and your going to be fine yes it's harder to see under that slag but it is do able !
It definitely is doable but should obviously be avoided lol. 7018 at 130amps didn’t have much issue. I have a feeling 6013 would be much different for results. Also, flux core wire will produce porosity without a doubt trying that. However in instances where you simply can’t prep things the best, stick is the best solution. It’s amazing what stick can weld though and still deposit a functional weld.
A friend of mine once had to interview a prospective welding specialist for a position at a company he was working at in Joburg, as he was somewhat knowledgeable about welding. After some questioning he started to suspect that the certificate the applicant brought along might be fake. He instructed to the prospective employee to weld a piece of metal to the cement floor. The guy set off furiously trying to accomplish the task, to the great entertainment of the entire staff, as the boss called everyone into the office one by one to show them the spectacle on the surveillance video.
@@makingmistakeswithgreg Wait till you know how many South Africans have fake drivers licences as they are intellectually incapable of passing the learners or drivers licence test😁 If you don't clean off the flux you definitely increase your chance of inclusions.
Very interesting test … I hardly every clean slag with multiple passes, and friends have always said it’s a no-no. They told me my welds wouldn’t be solid … but ur video shows it’s perfectly fine
I'm a bit of a lazy person, I like stick welding because I'll weld something down in a crevace where a mig gun won't fit, where I can't get a grinder in to clean up paint or rust or debris, and just burn it off and melt it in. I have left slag in place before (not an entire covering of slag, but bits where I couldn't get to it to knock it off,) and I always figured the weld was compromised, but at least it didn't break. Seeing this was surprising, as I didn't expect the amount of layer adhesion. I have welded over tacks without bothering to clean the slag off or feather them back without any adverse results, I think I even passed a couple bend tests doing that when I was in school and was even lazier than I am now. I like welding because it seems pretty forgiving, compared to woodworking or pottery. Steel is pretty strong, even a lousy weld done by a competent welder is usually strong enough to withstand whatever it is being used for. Most stuff I weld, the metal will bend well before the welds break.
The results definitely are surprising. Where I think slag entrapment would be a much bigger issue would be with cold beads where you have a row of slag on the side of the weld. Each pass I made had a uniform cover of slag, and no thick area near the weld toe (due to the bead being roped up). 6013 in particular can be really bad with that. I have a feeling welding over cold toes with slag instead of a fairly flat 7018 pass would end up far worse than the video. Even so the amount of slag I welded through I would have thought would have had far worse effects lol.
I will have to weld over a 6010 and see what happens. I know for a fact if you don’t clean the toes good enough on 6010 it’s very common to bust xray with what appears to be wagon tracks (lines of slag entrapment). I have a feeling slag entrapment would be easier to happen with 7018 over 6010.
Greetings, I have done it before Greg, so much until i understood how to make my tie ins perfect. The only difference is that i did it on horizontal, so the flux ran down on the bottom side of the previous bead, then i layed another on the upper end. Didn't have to fight against flux doing it like that. The right way is to clean the flux off though👍
I work in wrought iron here in my town by the border! Here the new home builder's use cheap labor from across the river! I cannot tell you how bad it is but I can say that every job I've seen,this is exactly the type of welds you find in the field!
Yes, you can stick weld over "some" slag. They just don't want you to know. There is a Pro Pipe Welder on RU-vid who welds over "some" slag all the time with 100% X-Ray required of every weld he makes.
The slag will just turn into a gas as soon as the arc hits it I reckon. It will then resettle along with the new slag to form a thicker layer. That's my guess. No way will the slag get in the way of a 6000 degree arc it's basically going to do what it does coming off a rod. But I'm sure it messes with your technique and visual awareness of arc length/rod angle unless you really get used to it.
I think it could work in some circumstances. I know you can bust xray for slag on the toes of 6010 welds. It looks like wagon wheel tracks on the film lol. If the welds are flat (where you don’t have a humped up bead with a slag line in the bottom) I bet the slag would mostly get burned out.
@@makingmistakeswithgreg I think he was talking about welding over slag on the cap. It's Taylor Welding on RU-vid. He's mostly retired now, but tells the truth. He even talks about welding with "wet" rods and how rod ovens are not needed. He has rod ovens, but only uses them when required by inspectors and Louisiana is humid..
I'm not particularly surprised. Slag is lighter than the metal and melts at a lower temperature. If there is even a hint of a bead once you finish the weld, that means the metal melted and the slag was already molten and would have floated up to the surface. Its hard to even imagine that slag could even get trapped under the bead. I don't know exactly if this is what was happening but if you watch at the beginning of his second pass, it looked like he even struggled to start the next bead until he knocked a little of the slag off to get a proper connection. The slag for the rest of the line wasn't a problem after that because the existing arc was preheating and melting the slag before the arc even got there.
It is very common to get slag entrapment with 6010 due to the nature of its slag. It tends to be small specs that get stuck in undercut that get welded over. One thin you must remember is I tend to weld pretty hot, and can make small adjustments to keep the arc under control. When I first learned to weld the results would have been drastically different than in the video. No doubt you are right though, the slag will melt and float. 7018 isn’t prone to trap slag like 6013 or 6010.
I have had to do this a time or two, but I prefer proper prep and flux removal between beads. However, the times I did do this, it has not failed, and I suspect it never will.
@@makingmistakeswithgreg Definitely not with 6013. But I have had enough failures to prove I need to be as good at prepping to weld as to solder or braze.
Spatter - blops! (What I called those little round things when working at Sunkist. I needed to clean them off pattern-packer frames to get them ready for painting.)
I have done welding over slag but its not an overly structural thing when I do it. Most the times I use Mig with flux core so the slag on top is quite thin so it works well enough. I have found going a bit slow at the start and giving a bit extra will get enough heat to allow the top layer to burn off or reflow. But again its not structural welding and more fill welding. Its a very situational use type thing and not an all the time.
Sounds like you have the right idea. Ideally it’s clean it off 100% of the time but that’s simply not practical all of the time and compromises must be made 😀.
Ross's weld came out clean too. If I remember correctly he ran his pass and immediately turned back on itself and did not give it time to cool down. I don't remember if it was him or someone else was saying that it was pretty common in some industries for a welder to tag team right behind the other straight through the slag.
@@makingmistakeswithgreg I don't remember exactly, I think it didn't turn out too bad though. You see in pipe welding especially where restarts are not cleaned. Even on 7018. It does help to get back into it as soon as possible though. I know for test I have done like a snake pattern back over the weld and it turned out ok. However I do not make a habit of welding over my slag. In the field i do clean my slag between passes. No point in taking chances.
Mentioning cables. I normally buy Excelene welding cable in 2 gauge. Last week I bought two lengths of it in 20 feet each. One red and one black. When it came in all it says on the cable are numbers every foot, or so indicating how many feet on the roll it was cut from. I sent a message to the supplier, one I’ve been using for several years about this, but haven’t received a reply yet. To say this is disturbing would be mild. I have no idea who makes these cables, or where they’re made. I’m hesitant to make anything from them. They weren’t cheap either, $115 for the total of 40 feet without shipping or tax.
I have been looking on marketplace for it, but my guess is it’s history. Unfortunately I live in a high crime, high drug area. I ended up forgetting it was in my truck and they broke in and stole it. I already have a new camera and will reshoot a ton of content, so it’s mostly a hickup in the road luckily.
6013 makes the worst slag in my opinion. I tried welding over 6013 slag and got too much porosity. That porosity would remain even if a big enough charge gives the electrode more penetration over sticky 6013 slag.
6013 is the worst no doubt. The worst stick welds I have ever done is with 6013. It does exactly like you said. If you don’t get porosity you surely will get slag inclusions that won’t disappear. Too low of amperage on a fillet weld is 100% slag entrapment with 6013 lol.
On a hole fill I generally use a new rod, and keep filling until the flux starts popping. I stop, clean the slag off, and start again (with 7018). 6010 you can generally keep going. With 6013 I bet you would get terrible slag entrapment lol.
Part of becoming a welder is to know what you can and can’t get away with to get a job done lol. There is always the book answer, and then what you have to do to get it done lol.
@@makingmistakeswithgreg Remember I was using a Nooter 8 pack of miller welders with a rheostat after every weld we turned up the amps until we were at 175 amps welding 3/32 on a reheat tubes. plus we used a chill ring.
I’ve bee forced to weld some really rusty steel at times. I don’t like it, but it is what it is. I crank up the heat high enough to burn through the rust, and go a bit slower I must have done something right, because I’ve not had a failure.
Rusty stuff can be a chore that’s for sure. Thankfully stick welding exists for that, I can’t imagine welding stuff like that with gas shielded mig lol.
When you hit 200+ amps wild things can happen. I have been doing a lot of air arc gouging at work lately and when you hit 300+ amps it’s amazing how much stuff melts when you have poor grounds, bad twist lock connectors, or broken power wires lol. I ended up going to a c-clamp style ground clamp due to failures of a few standard clamp type ones lol.
It’s a temporary lid for a sewer opening. It’s probably inch and 3/8th or more (can’t remember exactly). I got it for scrap price years ago. I believe it weighs over 335 lbs from what I remember. I actually picked it up once to put it on a dolly and it’s easily over 300lbs, I could feel my spine slightly compress lol. The table it sits on is just some spare wood I had that I threw together with casters. It works really well and I won’t be getting rid of it anytime soon lol.
I will have to try that. Based on what I saw if I can get the undercut better (which might be hard) a fillet weld might bend and not break. The bead placement issue will be tough to fix though, the beads don’t want to lay on one another lol.
car audio wire is also sometimes copper colored aluminum. It sucks! ...I replaced the 4ga resistor (in my car) with 2ga welding cable & it works much better! I was getting ~4v drop at ~160a with that shit, less than 1/2v with the welding wire!
Yeah some of that CCA wire is terrible. Car audio operates at such low voltages a small voltage drop is a massive spike in amperage draw and/or reduced output. A 4v drop is huge. Your amplifier thanks you for running solid copper 😀..
Me too lol. I thought for sure there was going to be a ton of defects. The undercut and weird bead spacing are defects, but that’s fixable on the surface atleast.
When I load the welder/gen up and take corded tools for a big job on the farm fence, I take different colored extension cords. I just handy for identification when tracing long cords. You could rap colored tape every few feet instead, but the color helps keep from tripping.
Yeah, I forgot I left it in my truck and someone decided to break the window and take it, along with my favorite pocket knife :(. I ended up buying a new camera already, definitely wasn’t planning on it ☹️
I hope my dad never sees this video because he yells at me for taking the time to clean my projects before welding them and he would never even imagine grinding the paint off. He has been stick welding since that was high tech so he can or will not change his mind and I have watched him weld over slag countless times and even paint over the slag when he is finished arguing that it is just more protection for the weld. If he sees this video he will surely take it as confirmation that his way is the best, but luckily since I am old he is ancient and has a hard time figuring out how to use a remote so I feel pretty safe keeping the secret. Lol
You can do it but it will bite you at some point lol. Had I done the weld with 6013 I know the results would have been far different and not good. I also ran the rod at 130amps, had I ran it at less amperage all bets would be off on how good it would have been lol.
Undercut comes from, 1. Arc length too long 2.Travel speed too fast. your ripple shape should be like the curve of a crescent moon not arrowshaped. 3. Amperage too high 4.angle on last pass too high. I taught welders to pass the Codes.I have been in the trade since 1967. Also the top pass should be allowed to cover 2/3rds of the bottom to avoid a mini valley between the two. Over all the weld is reasonable but can be improved to be spot on.
Great video! Supports the 7018 claim: "Its efficacy on rusty or painted metals makes it a practical option for field repairs, reducing the need for extensive surface preparation" ... (americanindustrialsupl)
That’s a pretty accurate description. The best way I can describe 7018 is it’s “old reliable”. When run decent its performance is both reliable and consistent. I have done probably 40 cut at etches with 7018 and it is virtually the same every time.
I'd argue that not cleaning after each pass saves you about 20 seconds per pass of clean-up time. That's 60 seconds. That's 60 seconds you could spend having sex with someone. So, you know, make up your own mind. Or a nice cup of tea.
Welding over slag is kind of like slapping a snake on the head to get it to run away. It will probably work for a while, but at some point you will get bitten lol.
@@makingmistakeswithgreg Come on mate, first you take the piss out of my welding style, now you're telling an Ozzy how to deal snakes! Let me tell you, if the snake runs away after you head slap it, you're not slapping it hard enough. PS, in Australia we call those running snakes' lizards. 😉
Neither did I lol. The two cap beads were way wide, which is weird because they didn’t look like it when I put the 3rd bead down. I bet if I did another and ignored what the arc looked like (just cram rod In) I could probably get rid of the undercut. Which would give a pretty solid weld. I would have lost a bet for sure, I would have never thought it would be even half as good lol.