Mig welding an Excavator boom.

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A good family friend has asked me to weld a crack in the boom of their excavator.  The crack is about 8-10" long.  I was going to weld it then plate it with some 1/2" steel. Does anybody have any helpful tips for me. I'll be using my ESAB Migmaster 275.Miller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:Pictures?Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Someone did a repair similiar to this not too long ago.I believe the recommendation was to grind off all the paint, then "V" groove the crack.Preheat was Optional? Somebody will answer this part....Get a nice hot fill in the crack, grind it flat.Then put the plate on "Fish" shaped, not just a square plate.It has to do with stopping the crack from propagating.....Last edited by drujinin; 05-14-2013 at 09:45 AM.Reason: Too early to spell correct
Reply:I'd drill a hole at each end of the crack!Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:So far everything stated is what I was going to do with the beveling the crack and removing all the paint.  But the "fish" shape plate might not work because of its location.  It goes around a 90degree edge. Ill post pics in a bitMiller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:[IMG][/IMG] [IMG][/IMG]Miller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:Step #1 - Find out what the boom material is!  Not all booms are mild steel or use mild steel filler.Once Step #1 is done, that determines what filler is appropriate and what preheat may be necessary.General procedure : Remove anything that is not clean shiny steel from the area to be welded and at least 1-2 inches in any direction.  No paint or rust or mud or grease.  Once the area is cleaned, check for any further cracking.  Clean more if needed.  Stop-drill ends of crack(s) and bevel out crack as needed to ensure getting complete penetration when you weld it all up.  After welding the crack(s), grind flat and reinforce the area with fish plate(s).But it all starts with Step #1.    The best laid schemes ... Gang oft agley ...
Reply:Be sure to do the cleaning and paint removal before deciding that the crack stops X here. Adding some low heat just enough to turn the steel blue will help in visualizing the cracks, and their true end points.In Alaska I always use a filler that has at lease a 20ft/lbs at -20F rating.Last edited by Fat Bastard; 05-14-2013 at 01:06 PM.
Reply:I agree, definitely stop drill, all the way through the plate once you determine where the crack actually stops! Since it is in a weird location too, maybe run a cover pass on it as well. Aren't most of these booms HRS plate welded together? I see the curve in the surface, I am assuming it is for strength? Looks like a pretty strait forward repair as I see it.We deal with stress cracks on planes all the time and, depending on the length and location, just stop drill them and let them fly, if it is serious or out of limits, we will replace the material or build a new piece entirely.Good luck!
Reply:This is very helpful in these situations. http://www.grainger.com/Grainger/SPO...rant-Kit-3WU63Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Originally Posted by CEPThis is very helpful in these situations. http://www.grainger.com/Grainger/SPO...rant-Kit-3WU63
Reply:Does that crack go all the way to the pivot pin ?Can't tell from the picBacked 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:Thank you all for the prompt responses. How can I plate this location. Should I heat and bend the metal to have it be all one piece or have 2 or 3  pieces of plate to make the bend?  also I have to buy more welding wire since mine is getting low should I stay with ER70S-6 or go with something else. I was thinking about getting a 33 pounds spool of .040 ER70S-3Miller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:Originally Posted by SpyderTB?..  also I have to buy more welding wire since mine is getting low should I stay with ER70S-6 or go with something else. I was thinking about getting a 33 pounds spool of .040 ER70S-3
Reply:I can't tell what type of machine this is from pics.  Keep in mind that there are likely gussets inside of the boom. Also, do you know why the boom cracked?We own JD, CAT and Komatsu excavators and during manufacture, all booms, sticks, etc. undergo post weld stress relief. I realize this is tough for most of us to do and size of repair will determine any need.
Reply:Drill ends back gouge weld with 250 preheat Outershield 71 Elite .045 , no plare reinforcement needed.Check with mag or dye pen. Or use E-7018 5/32  min ,no little rods not enough heat imput in the weld zone.   John
Reply:The machine is a 1987 john deere 610C. The crack isn't by the pin so no worry there. The boom cracked from them using the bucket to drive in pylons.  Lol not really what its ment for. Its a small construction company with 5 workers. My buddy and his brother, their father and 2 other hires.Last edited by SpyderTB; 05-15-2013 at 07:50 AM.Miller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:Is it my imagination, but is that flat section buckeled outward?Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Odds are its not just mild steel. A lot of heavy equipment is T100 which is really bad about cracking if welded improperly. If it were me I would clean it up real good and preheat it to burn off any hydrogen then weld with 9018 and rap in a welding blanket. Good luck
Reply:Originally Posted by SpyderTBThe machine is a 1987 john deere 610C. The crack isn't by the pin so no worry there. The boom cracked from them using the bucket to drive in pylons.  Lol not really what its ment for. Its a small construction company with 5 workers. My buddy and his brother, their father and 2 other hires.
Reply:For some reason I cannot see the pictures, but if its and small excavator and the parent metal thickness is 3/4" or less, which it will be, you wont really need to pre heat, just bring it up to 80-90 F.  gouge out the cracks plus a little more, spend some quality time with your grinder, weld it back up with some 71T-1 or 7018 and put it back in the dirt...........simple every day repair really...........Just re-read the original post.........10 inch crack= 5 hours start to finish, then back in the dirt....no worries.Last edited by ExpatWelder; 05-15-2013 at 09:15 AM.Reason: re read post6 Miller Big Blue 600 Air Paks2 Miller 400D6 Lincoln LN-25's4 Miller Xtreme 12VS2 Miller Dimension 812 4 Climax BW-3000Z bore welders Hypertherm 65 and 85Bug-O Track BugPair of Welpers
Reply:Originally Posted by CEPI'd drill a hole at each end of the crack!
Reply:I went over there tonight. Sorry my memory misleadd me its an 1988  690CMiller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:If I were you I would use a stick welder but if you have to use a mig welder I would use flux cored for welding that nasty crack. Make sure to grind out a nice V grove and I concur with CEP and find the ends and drill a hole to stop the cracking.Good luck and have fun. Originally Posted by SpyderTBThank you all for the prompt responses. How can I plate this location. Should I heat and bend the metal to have it be all one piece or have 2 or 3  pieces of plate to make the bend?  also I have to buy more welding wire since mine is getting low should I stay with ER70S-6 or go with something else. I was thinking about getting a 33 pounds spool of .040 ER70S-3
Reply:Originally Posted by Pete.S.Something like this?Hydrogen cracking. Plain and simple...... use 7018 stick. Heat the rods. Follow all the prep advice given, and send it back to the field.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Yup. That is where the crack In.  I called my JD rep. They don't know what grade of metal the boom is eithet. After looking at my welder.  I can use  .045 wire without changing the liner. So when I buy the spools I'll be getting both 030 & 045. My stick welder at the farm is a very old Forney C5. And I have to fix the power cord on it if I wanted to use it. As many people stated.  I need to find out the metal first.  How do I do that.  I'm not trying to be a smart a$$ but I don't know.  I'm Just a small town farmer.Last edited by SpyderTB; 05-16-2013 at 12:21 PM.Miller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:Since you do not have a working stick welder for 7018 - how about an equivalent Self-shielded Flux-core wire?http://www.hobartbrothers.com/index....01returnid=523Any of you pros that use T-8 wire on the job know if that would work for him?Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Sorry should have said to the "left" of Deere logo. The pic I thought I downloaded was reversed image wise.anyway, the damage likely resulted from extending bucket to full dump position  with the dipper stick fully extended. Some operators do this to loosen mud or stuck material from the bucket. You have some sound advice for repairs here.Good luck k
Reply:If 7018 is out of the question lincoln makes a pretty good dual sheild .045
Reply:Originally Posted by MinnesotaDaveAny of you pros that use T-8 wire on the job know if that would work for him?
Reply:The last excavator boom I did, I used Hobart ExelArc71 dualshield. The guys have been beating it regularly ever since I fixed it and there are no signs of problems.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:I was wondering when you would chime in and set them straight......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by TozziWeldingThe last excavator boom I did, I used Hobart ExelArc71 dualshield. The guys have been beating it regularly ever since I fixed it and there are no signs of problems.
Reply:Originally Posted by CEPNR-232, NR-233, and Coreshield 8 would all be good choices. But these wires are not for the average home owner's Mig machine!
Reply:Originally Posted by MinnesotaDaveHis Esab Migmaster 275 isn't "enough gun" ?Dave J.
Reply:Originally Posted by WookieWeldingunless he can push 0.068 0.072 5/64 for nr2321/16 0.072 5/64 for NR233
Reply:Originally Posted by MinnesotaDaveI see now - I was thinking small wire - .045My mistake  Dave J.
Reply:Originally Posted by MinnesotaDaveHis Esab Migmaster 275 isn't "enough gun" ?Dave J.
Reply:That boom is A572 GR 50 or maybe A-36 they wont be press braking the radius with T-1 .Get a roll of Outershield 71 Elite in .045 do not mess with ESAB its crap or innershield for a shop repair it is also hard to weld with . Crank up the Forney get some AC carbons or forney cutting electrodes . If not Grind and die grind to cracks ends . Preheat and weld up ..Carbon entrapment with carbon arc will put the crack right back make it clean .  The ESAB 275 will run the wire fine we have run over100 tons of it in the World Trade center.
Reply:Originally Posted by PavinsteelmanThat boom is A572 GR 50 or maybe A-36 they wont be press braking the radius with T-1 .Get a roll of Outershield 71 Elite in .045 do not mess with ESAB its crap or innershield for a shop repair it is also hard to weld with . Crank up the Forney get some AC carbons or forney cutting electrodes . If not Grind and die grind to cracks ends . Preheat and weld up ..Carbon entrapment with carbon arc will put the crack right back make it clean .  The ESAB 275 will run the wire fine we have run over100 tons of it in the World Trade center.
Reply:Originally Posted by farmersammInteresting thing about wire.  After the North Ridge quakes it was found that a lot of wire welds failed, they weren't able to resist seismic stress.After the findings it was interesting to see that the wire manufacturers re-rated, or re-formulated their wires to resist seismic stress.  One wonders if it's actually just the same wire with a different label.I'm not sure about this dood, read some of his stuff before but.............take it for what it's worth.....http://www.weldreality.com/north%20r...ke%20story.htmMakes you wonder if the stuff these companies now market as suitable filler is actually suitable?????????????????  Wouldn't be the first time Corporate America lied to the people.
Reply:.............You are analysing this to death...........If all you have is E70S-6.......use it and you will be fine.........its all in the prep.  Gouge, grind, grind some more, grind a little more, then weld it up, taper the edge of the cap back an inch or 2 from any edge, smooth.  I weld up booms that make that thing look like a toothpick on a daily basis, mostly with 71T-1, or 70S-6. You are way better off to have the weld strength under the parent material strength, than to go the other way................Let us know how it turns out and get it back in the dirt.6 Miller Big Blue 600 Air Paks2 Miller 400D6 Lincoln LN-25's4 Miller Xtreme 12VS2 Miller Dimension 812 4 Climax BW-3000Z bore welders Hypertherm 65 and 85Bug-O Track BugPair of Welpers
Reply:My C5 needs work done to it, so I will not be welding with it.  If I were I would use E7018. I spoke to the JD facility about the boom material neither the sales rep or mechanics knew what kind of metal it was since they don't do welding at their shop. Also I spoke to my welding supply store.  They suggested that I go with a Lincoln wire over the esab. They said that the comparable wire for Lincoln has more silica in it than the ER70S-6. I understand that the preparation is the most important part of the job. I will be going over to the location of the machine tonight and some of tomorrow to start on the prep. I picked up some dye to use on the crack. And yes I will be using it for my cars too. I am restoring a 1964 Impala SS right now.  It's been a 3 yr process so far.  It started as a basket case. Now the body is back on the frame and im working on replacing the other quarter as we speak.  So for 3 years now I've been cutting and welding on it non stop.Miller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:The wire they were talking about is SuperArc L-56 and L-59 fyiMiller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:Expat   Tozzi   and steelman and you will be fine as long as the welding is good.
Reply:Ok. I trust my ability to weld and always spend a good amount of time preparing the area to be welded. I just really over think and over analyze things.  I will be taking plenty of photos with before and after results.  I also found out that they were using the bucket to pound in I beams when it cracked.  So it was NOT because of semi normal use. They flat out abused the machine.Miller Syncrowave 200Esab Migmaster 275Miller Millermatic 210Forney C-5Hypertherm Powermax 30
Reply:Lincoln material is the best all bridge fabricators use it ,we have been in busness 103 years only red and grey in our shop and we buy by the truckload. Outershield 71 elite in 045 will will work fine and so will .045 L-56 : Preparation and preheat is important.It is better to underweld in highly restrained conditions to prevent cracking . When we run HPS 70W to A709GR 50. LA-75 is used than LA -85 due to this.  John
Reply:All welding is 2/3 prep work....All operators are abusive..some are just better at it than others Do what Expat said and get'er doneBacked 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:Ok lets see some pics of the project and finished product.