CAT 416D "Fix"

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Here goes....hi all, I had this little welding job the other day, am hoping for some critiques of my welds.This is a small plate, probably something like 12" x 8" x 3/4", on the back of the stick where the extend-a-hoe comes out.  The bolts keep breaking off and so after consulting CAT, it was decided to replace the bolts once more, and weld the plate on the end where it breaks first.  It's not a structural weld, just supposed to add enough strength to keep the bolts from snapping off.Millermatic 252 running .035 solid, 75/25, somewhere around 25V/450 if I remember correctly.  I made some adjustments along the way, not used to welding this thick of material and had nothing to practice on.
Reply:Next passes...
Reply:Final passes...
Reply:i would have up welded that
Reply:I would think that because it was ground out and filled in that downhill would work. Could be wrong but if so it is his equipment and he can do it again.  I just don't think a lack of penetration will be a problem in this case.
Reply:definitely an uphill job.  I would have ran 7018 not mig...Journeyman / Red Seal Welder (What a useless test)Miller CST 280Miller XMT 350Miller 12vs XtremeEvolution Evo 28 mag drillEvolution 380 Dry Cut saw
Reply:Originally Posted by Newfie_1986definitely an uphill job.  I would have ran 7018 not mig...
Reply:CCS, I'm far from an expert in equipment repair. To me, your welds look good but I feel you should have overlapped your cover pass. I don't see the point in that third stringer over parent material while the other two are not overlapped.Does it matter?, in reality probably not.I see you used grade 10.9 bolts, would a higher grade help?Could you post an overall pic for my curiosity.Sent from my XT907 using TapatalkLincoln SA 200Esab Caddy 160Thermal Arc 201TSMiller Dialarc HFI don't like making plans for the day because then the word "premeditated" gets thrown around the courtroom....
Reply:Should have done vertical up for max pen7018 would have been better alsoSent from my SPH-D700 using Tapatalk 2Backed my CATMA over your CARMA oops clusmy me  What would SATAN do ?? Miller Trailblazer 302 AirPakMiller Digital Elite  Optrel Welding HatArcair K4000Suitcase 12RC / 12 VSHypertherm PM-45Rage 3 sawRusty old Truck
Reply:There's nothing wrong with using MIG for this job, but should have been done vertical up with Mig, vertical down mig is for thin plate (under 1/4 inch), and even then, not for critical weld's, That will last longer then it otherwise would have, but eventually the weld will crack and need to be re-welded.Last edited by ttoks; 04-21-2014 at 03:19 AM.
Reply:My only good advice is pick a different gas for this heavy of welding.
Reply:......and no preheat was done becuz???Blackbird
Reply:Hello CCS, your prep. work looks good. The issues with your actual repair process could be discussed and debated at length. Vertical down with solid wire on heavier materials(1/4" and up) will often result with insufficient fusion between the applied weld metal and the base metal, in a nutshell. Solid wire vertical down doesn't possess any of the characteristics of other welding processes or wire types with regard to penetration and proper fusion. Vertical up with solid wire also has a lot of associated challenges as it has no elements to assist with holding the molten weld material in place. You can "trigger" solid wire in in a vertical up scenario and at least have better to sufficient penetration. Flux-cored with or without gas is often a good choice for something like this or else fall back on the old stand-by: E7018 SMAW. If I had a little bit more time I could explain a lot of this better, have to run for now though. Good luck and best regards, Allanaevald
Reply:Here is my question then about uphill or downhill.  If you bevel the weld out to the point that you have a 1/8" land and then fill in the bevel with weld material to equal or slightly exceed the parent material why does it matter if you go uphill or downhill?  Is something happening with the greater heat input of the uphill (mixing of the parent and weld metal) that is not achieved with the downhill?  Would it be possible in the right scenario to weld it correctly downhill?  Does uphill give a better chance of a strong weld?  I have some ideas about this but am interested in others input on the subject.  Thanks
Reply:Thanks for the replies and advice.  I've never had any luck trying vertical up with a mig, but I don't know the technique either.  I would have loved to weld it uphill with 7018, I'm just not confident enough in my welding to do it.cd19  -  What would be a better gas for heavy welding?aevald  -  Thanks for your detailed answer, helped me a lot.Am eagerly awaiting an answer to Canner's question as I'm wondering the same thing.
Reply:Jody does a decent job explaining it:http://www.weldingtipsandtricks.com/...technique.html
Reply:Ccs, vertical up with solid wire mig isn't all that tough. I can usually get most students dialed in if they can do decent flat and horizontal welds, in a few hours of class time.If you post up some picts of your tries at doing it, list material thickness, wire size voltage settings and so on I bet we can get you dialed in pretty quick if you can already read the puddle. Most of what we teach with is 1/8" using .035 solid using 92/8 so most of the settings I know off the top of my head are for that. C25 settings will be off slightly, but not all that far and if I see your welds I can probably get you tuned in pretty close..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by CannerHere is my question then about uphill or downhill.  If you bevel the weld out to the point that you have a 1/8" land and then fill in the bevel with weld material to equal or slightly exceed the parent material why does it matter if you go uphill or downhill?  Is something happening with the greater heat input of the uphill (mixing of the parent and weld metal) that is not achieved with the downhill?  Would it be possible in the right scenario to weld it correctly downhill?  Does uphill give a better chance of a strong weld?  I have some ideas about this but am interested in others input on the subject.  Thanks
Reply:Originally Posted by ttoksDownhill, particulary on thick materials, can be prone to lack of fusion, the weld pool roll's over the parent metal, without melting into it, on thin material, this isn't as much of a problem, on thicker materials, which act as a greater heat sink, sucking the heat from the weld area, this can be a rather big problem.
Reply:Originally Posted by ccsThanks for the replies and advice.  I've never had any luck trying vertical up with a mig, but I don't know the technique either.  I would have loved to weld it uphill with 7018, I'm just not confident enough in my welding to do it.cd19  -  What would be a better gas for heavy welding?.
Reply:Spray transfer does not work well for vertical welds, the puddle is too fluid. Given the OP's machine and gas, I would choose dual-shield.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:I would have to concur I would of ran 8018s or greater for any piece of hydraulic earth mover. Stronger strength vs a mig weld. I forsee cracks in the not so distant future...~1987 Lincoln Sa-200~~1978 Miller Big 40~ (restored) ~and everything inbetween~
Reply:Ok, so here's my first real tries at uphill.I watched Jody's video and tried to copy his technique.Millermatic 252   .035 wire   19V/270 75/25   material is 1/4" strapI thought that I was moving too fast and my wire speed was too high, so I changed it to 19/250.I tried turning it down again 19/240.Do those look at least someone right?  And it seemed like I had a little more trouble when I did the lowest weld on each piece, I couldn't get my gun angle up much, does it even matter or is that just my imagination?
Reply:i like them, now do your best down hill weld and break them...keep posting
Reply:What would be the best way to break them?I've got some tack's on the backside, should I grind them out first?I'm thinking maybe put one side in the vise and beat the crap out of the other side, one way and then the other?Double T, 10.9 bolts are what Cat uses for 98% of there metric machines.  If they are breaking those bolts I bet the problem lies elsewhere.
Reply:Originally Posted by jd-11Double T, 10.9 bolts are what Cat uses for 98% of there metric machines.  If they are breaking those bolts I bet the problem lies elsewhere.
Reply:I cant speak for the design but the welding is all wrong. I think yhe op is in over his head.1) never weld structural down hill2) ER70s6 is not for structural3) welds should overlap by one half4) depending on the parent metal, preheat may be neededThe filler should have been a dual shielded wire or low hydrogen electode ran up hill.the parent metal should be identified so the proper filler can be selected.
Reply:Originally Posted by ccsOk, so here's my first real tries at uphill.I watched Jody's video and tried to copy his technique.Millermatic 252   .035 wire   19V/270 75/25   material is 1/4" strapI thought that I was moving too fast and my wire speed was too high, so I changed it to 19/250.I tried turning it down again 19/240.Do those look at least someone right?  And it seemed like I had a little more trouble when I did the lowest weld on each piece, I couldn't get my gun angle up much, does it even matter or is that just my imagination?
Reply:Originally Posted by jamesyarbroughI cant speak for the design but the welding is all wrong. I think yhe op is in over his head.1) never weld structural down hill2) ER70s6 is not for structural3) welds should overlap by one half4) depending on the parent metal, preheat may be neededThe filler should have been a dual shielded wire or low hydrogen electode ran up hill.the parent metal should be identified so the proper filler can be selected.
Reply:ER 70 S 6 ... i can understand it will not be as good as 11018 or similar stick up hill . But manufacturer recommends it in some demanding applications.APPLICATIONS: Frame fabrication, automotive structures, farm implements, construction equipment, pressure vessels, pipe fabrication, railcar construction and repair, general fabrication. Widely used in high-speed robotic and automatic welding applications and semi-automatic application.source:            http://www.unibraze.com/DataSheets/Data70S-6.pdfif sillicon islands were  present on top of weld and havent been brushed, shorter life expectancy for that repair...  Now that the op made the job , why not test it...worse case it will crack then grind and re-do with state of the art procedure. It may well last quite a while
Reply:Thanks DSW, very helpful.  I'm going out of town for a couple days, but when I get back I try and do some more with your suggestions and repost.All of those welds have somewhat of a ridge in the middle, is that fairly normal for vertical up w/ mig, or should it be pretty flat?As to the questions of whether the fix will hold up, or whether it was the right thing to do to weld it up, or whether there is some underlying problem that was not addressed with this fix, I'd be happy to attempt to shed some light on some of that, but honestly, I'm mostly interested in learning to weld better.  I think my time would be better spent talking about welds than trying to defend the decision to weld it in the first place, but up to you guys, if you want I'll try and defend it!  heheAnd I do agree w/ james, op is basically over his head, but wanting to learn something   Thanks for the advice James.
Reply:Originally Posted by ccsThanks DSW, very helpful.  I'm going out of town for a couple days, but when I get back I try and do some more with your suggestions and repost.All of those welds have somewhat of a ridge in the middle, is that fairly normal for vertical up w/ mig, or should it be pretty flat?As to the questions of whether the fix will hold up, or whether it was the right thing to do to weld it up, or whether there is some underlying problem that was not addressed with this fix, I'd be happy to attempt to shed some light on some of that, but honestly, I'm mostly interested in learning to weld better.  I think my time would be better spent talking about welds than trying to defend the decision to weld it in the first place, but up to you guys, if you want I'll try and defend it!  heheAnd I do agree w/ james, op is basically over his head, but wanting to learn something   Thanks for the advice James.
Reply:Originally Posted by ccsThanks DSW, very helpful.  I'm going out of town for a couple days, but when I get back I try and do some more with your suggestions and repost.All of those welds have somewhat of a ridge in the middle, is that fairly normal for vertical up w/ mig, or should it be pretty flat?
Reply:Finally got some time to try again, here's some pics:I tried your advice DSW, don't think I really succeeded.It's 1/4 strap again, turned up to 19.5/270, tried to go faster and tighter.
Reply:
Reply:Ccs.  I'm interested in knowing the longevity of this repair.   I'm going out on a limb here and predict a crack on the outside edge of weld.   Are the wear plates on the inside of the boom worn allowing flop between the in boom and outer boom every time the bucket is raised or lowered?  The constant impact between the inner and outer boom is what will break the bolts.   It will now break the bolts and break the now hardened steel on the outside edge of the weld beads if the wear plates are worn and the impact between the booms continue.   Just something to check.   Keep us posted.Lincoln Electric:Ranger GXT 250SA-200LN-25Pro MiG 256Pro Mig 180Esab CV 251Invertec 160Victor Torches”
Reply:Thanks for your interest Ex, you're not the only one that is pretty sure it will break soon haha .  This hoe doesn't get used a lot, it's been a year or two between previous fixes before the bolts popped, so I expect it'll be that long and then some this time.  The wear plates are not warn anywhere near past tolerance.  This was confirmed by the CAT field mechanic that came out to help diagnose and perform this last repair.  He replaced two wear plates (neither of which were very bad according to him) just to be on the safe side.  What did seem to be the case, however, was that at least some of the bolts were bottomed out.  That could cause there to be a slight amount of play between the plate and the boom, which could obviously break the bolts after a while.  The mechanic added an extra washer to a couple of bolts to keep them from bottoming out this time, that may have solved the problem, dunno, the weld is an extra precaution as well as a potential early warning indicator as a person might see it start to crack before bolts start breaking.
Reply:Better ( If I remember the originals). However I'd still be even tighter, I'd have almost twice, if not almost 3 times the number of motions in what you have. I can still easily see where each side to side motion didn't fill the sides well. You want the toes to be one smooth even edge, not the notched edge I'm seeing. The one on the left 1st pict looks the best but still needs some work.Your consistency looks pretty good. All the motions look the same and your distance up each time looks to be almost exactly the same. Now all you need to do is tweak your settings and tighten up a bit more. I'd start 1st with getting your motions tighter and adjust your travel speed if needed 1st, and then do some minor adjustments on your settings if need be to get a flatter bead if adjusting your motions doesn't do this for you. Looks like you are pretty close from what I can see. It's hard to tell in those picts how "lumped" the center is, but it doesn't look horrendous. Sometimes you need to overcompensate and end up with a slightly concave center so you know how far you can push it. then dial things back until you are just convex again. Some of this is easier to do in person than try to explain by text..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Thanks again DSW for the help.  I tried quite a bit to make more and tighter motions as you suggested after my 1st attempt.  I really didn't have much luck doing that, so maybe you can clear this up a bit.  My understanding of this vertical up technique is that you want to spend your time on the sides and not in the middle, just pass across the middle.  When I spend more time in the middle, I think I get more of a hump.  And when I try and do tighter motions (2X or 3X the number), I end up spending about as much time in the middle as on the sides, as the pause on each side is greatly reduced.  So it seemed like I had more trouble when doing this with a hump in the middle, and the sides maybe even undercutting occasionally.  When I slow down these problems go away at least a bit.  What am I missing about this technique?
Reply:Originally Posted by ccsThanks for your interest Ex, you're not the only one that is pretty sure it will break soon haha .  This hoe doesn't get used a lot, it's been a year or two between previous fixes before the bolts popped, so I expect it'll be that long and then some this time.  The wear plates are not warn anywhere near past tolerance.  This was confirmed by the CAT field mechanic that came out to help diagnose and perform this last repair.  He replaced two wear plates (neither of which were very bad according to him) just to be on the safe side.  What did seem to be the case, however, was that at least some of the bolts were bottomed out.  That could cause there to be a slight amount of play between the plate and the boom, which could obviously break the bolts after a while.  The mechanic added an extra washer to a couple of bolts to keep them from bottoming out this time, that may have solved the problem, dunno, the weld is an extra precaution as well as a potential early warning indicator as a person might see it start to crack before bolts start breaking.
Reply:Thanks Ex, hope you're right!