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  • Electrode selection

    Have mainly just been doing hobby and general repair welding, but have a project coming up that requires welding some thicker mild steel. We're beefing up the floor of an older dump trailer for hauling boulders. Steel thickness will be 1/2" to 5/8" thick. The welds don't have to be pretty but I want to do a decent job. I plan to use 1/8" 6010 for the root and may cap with 7014 or 7024. I am using an older Miller big 40, so power is not a problem. Any suggestions for rod selection and size would be appreciated.
    Snidley :}
    Here in the Great White North
    Mosquitoes can't fly at 40 below

  • #2
    Re: Electrode selection

    Originally posted by Snidley
    Have mainly just been doing hobby and general repair welding, but have a project coming up that requires welding some thicker mild steel. We're beefing up the floor of an older dump trailer for hauling boulders. Steel thickness will be 1/2" to 5/8" thick. The welds don't have to be pretty but I want to do a decent job. I plan to use 1/8" 6010 for the root and may cap with 7014 or 7024. I am using an older Miller big 40, so power is not a problem. Any suggestions for rod selection and size would be appreciated.
    That sounds reasonable...I would use 7018, and that only bcause I've got 200# of it in my hot box. You might want to go to 5/32" rod, tho, to speed things up a bit. Just an idea.

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    • #3
      Re: Electrode selection

      Originally posted by Snidley
      Have mainly just been doing hobby and general repair welding, but have a project coming up that requires welding some thicker mild steel. We're beefing up the floor of an older dump trailer for hauling boulders. Steel thickness will be 1/2" to 5/8" thick. The welds don't have to be pretty but I want to do a decent job. I plan to use 1/8" 6010 for the root and may cap with 7014 or 7024. I am using an older Miller big 40, so power is not a problem. Any suggestions for rod selection and size would be appreciated.
      Sounds good, I would use 6011 for the root and finish with 7018, but I just like that rod, and as Rocky said, you may want to go 5/32 to speed things a little.
      ROCK

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      • #4
        Since I don't do welding on a regular basis ( only when things need to be fixed or a project) I haven't really considered 7018 rods. The main reason is I don't have a storage oven. It seems like a fairly large expense for infrequent use or should I consider one for the long run?

        Last edited by Snidley; 01-29-2003, 08:34 AM.
        Snidley :}
        Here in the Great White North
        Mosquitoes can't fly at 40 below

        Comment


        • #5
          It was years before I knew about the 4 hour maximum that is required by AWS code, of having your Lo-Hy rods out in the atmosphere. We welded everything with 7018 and never had an issue of hydrogen cracking. Since you're not doing code welding, you could be safe just keeping your rods in a warm dry place, not necessarily in a 250 degree rod oven.

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          • #6
            Rock, if you are going to leave them out in the atmosphere you wil be better off to save some money and buy something less expensive than low hydrogen. The reason many people never have a problem using old saturated lo-hyd. electrodes is you need three things for cold cracking to occur. 1) A susceptible microstructure 2) Sufficient stress 3) A source of hydrogen. The other thing most people don't know is metal under 1/2" is unlikely to crack due to hydrogen diffusion or cold cracking. In fact carbon steel under 1/2" or even 5/8" has no reason to even use low hydrogen electrodes. Cold cracking from hydrogen diffusion takes place usually well after the weld has cooled, up to 72 hours after welding. So if your weld is cracking as it cools, it is not hydrogen cracking. That concludes todays lesson in cold cracking. Have fun guys and as far as a truck bed liner goes, I have installed many of them including aluminum, Hardox 400, carbon steel and heated beds. I would use GMAW or FCAW.
            Respectfully,
            Mike Sherman
            Shermans Welding

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            • #7
              What electrode type & sizes should one use on thick material?

              I was just going back through my old class notes and it didn't specify types to use, but for sizes it mentioned that for over 1/4" thick to use 5/32 rods, for over 3/8" thick to use 3/16" to 1/4" and for 1/2" and over to use 5/16" rods.

              Were these just optimum sizes to use for single pass welds, or are you better to use a smaller rod and do multiple passes?

              any comments? Thanks.
              Snidley :}
              Here in the Great White North
              Mosquitoes can't fly at 40 below

              Comment


              • #8
                Snidley, those sizes are way bigger than anything I would suggest. I hardly ever use anything over 1/8". For out of position welding, 1/8" is all you need. For flat, you can use larger but unless you are welding alot of steel, stick with the 3/32" or 1/8". I do use 5/32" E6010, but only occasionally on pipe. I stock some E7018 in 5/32" also, but I haven't used it in ages.
                Respectfully,
                Mike Sherman
                Shermans Welding

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                • #9
                  Thanks to everyone for their input.

                  This is going to be outdoor work/project so I still have at least 2 to 2-1/2 months before it's warm enough to get at it.
                  Snidley :}
                  Here in the Great White North
                  Mosquitoes can't fly at 40 below

                  Comment


                  • #10
                    Snidley


                    I personally wouldn t use anything larger then a 5/32 diameter rod. The 3/16 and above diameters are going to run at some pretty higher current settings, and if your using DC the higher current settings are going to give you more arc blow problems then the smaller diameter rods that run at a lower current setting. For groove joint like you ll be doing I d probably use a 1/8" diameter rod.
                    MigMaster 250- Smooth arc with a good touch of softness to it. Good weld puddle wetout. Light spatter producer.
                    Ironman 230 - Soft arc with a touch of agressiveness to it. Very good weld puddle wet out. Light spatter producer.


                    PM 180C



                    HH 125 EZ - impressive little fluxcore only unit

                    Comment


                    • #11
                      If I had to weld this trailer floor ,I'd use 7/32 or 3/16 dia. 6027 on the flat, do it in one pass and make some time.
                      A Big 40 has more than sufficent power to run these.
                      Out of position beads I'd make with 5/32 or 1/8 6011.
                      Mike's suggestion of not using anything larger than 1/8 is OK if you want to make multi- pass welds on the 1/2- 5/8 plate, otherwise, I'd try for single pass and, and get it done quickly.
                      7024 is also a good rod for this, but since I've not run this since 1978 or 1979,I'm not as comfortable telling you to use it.
                      If you could get a wire feeder, running flux core
                      would be the best on this project.
                      Last edited by Ed Heimbach; 02-07-2003, 01:53 AM.
                      work safe, always wear your safety glasses.


                      Edward Heimbach

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                      • #12
                        Ed...

                        I had a chance to try out some large diameter 5/32 & 3/16" electrodes. What a blast. Everyone should try them once.

                        This was just for testing, and it was lots of fun welding 5/8 thick steel with big sticks. It amazing how much metal you can put down in pass. Those sticks are sure long too.

                        The welder just grunts a little bit more in the beginning to get started, but worked out well with no lack of power problems. Certainly heats things up quite a bit more.

                        Not working on the trailer yet. Still to cold. Just thought I'd let everyone know I'm still testing and practicing some of the suggestions.
                        Snidley :}
                        Here in the Great White North
                        Mosquitoes can't fly at 40 below

                        Comment


                        • #13
                          Snidley, Since you discovered that big sticks = big heat, one other thing you need to know is that the tendency for the steel to warp and buckle is greater when using big rods.
                          More attention should be given to joint preparation, especially having the steel tack welded in many spots to try to help contain the distortion.
                          Any of the better welding handbooks have info. on how to deal with heat distortion. With propper set-ups the tendency of the steel to pull and buckle can be used to your advantage.
                          work safe, always wear your safety glasses.


                          Edward Heimbach

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