Miller Electric

Welding Discussion Forums

Home » Resources » Communities » Welding Discussion Forums
Miller Welding Discussion Forums - Powered by vBulletin

Results 1 to 9 of 9

Hybrid View

  1. #1
    Join Date
    Mar 2006

    Default exaust manifold crack welding?

    I have to weld a crack in an exaust manifold and aint sure what to use, don't know if I should stick weld or mig it, and what type of rod to use if thats the case any help would be great thanks

  2. #2
    Join Date
    Sep 2002
    Clark County, NV


    I did one that is still on the road. I ground out the crack and used an old Eutectic rod that I don't know the composition of. The second pass was with E309 stainless.

    Edit: Oh yeah, preheat and SLOW cool.

  3. #3
    Join Date
    Sep 2005
    Salem ,Ohio


    Exhaust manifolds are hit and miss because all the good stuff is burned out. I just used 7018 when i did them years back. Cast or SS rod would be ideal if you want to spend the money...Bob
    Bob Wright, Grandson of Tee Nee Boat Trailer Founder
    Metal Master Fab Salem, Oh 44460
    Birthplace of the Silver & Deming Drill
    1999 MM185 w/185 Spoolgun,1986 Thunderbolt AC/DC
    Spool Gun conversion. How To Do It. Below.

  4. #4
    Join Date
    Jan 2006
    long sault ontario canada

    Default Patience

    That is the key to weld the manifold,first you preheat till the peice stops really stinking and starts to clean up (about 350 deg) on its own
    Everthing depends on judgment ie ;material thickness ,so on age is a big thing because older cast tend to get brittle over time you can braze the peice if you want or stick weld it there are lots of good cast rods available if you choose that rouht make sure you peen between welds to releive internal stresses cover the peice in sand after or wrap it in a weld blanket and let cool slowly
    smokin ana grinnin for 20 years
    trailblazer 302
    hobart suitcase mig
    miller 30a al spool gun
    laramy plastic welder
    brocco cutter
    pipe beveler
    all walter hand tools

  5. #5
    Join Date
    Sep 2005

    Red face I would braze it...

    I have done several and I brazed them. I "V" out around the crack good and then I preheat them like they said. I then load it up with flux and have at it. I have even done one on my old 292 Ford that I cut the flange off and removed a section to adjust the angle, and then brazed it back together. That was 8 years ago...

    I dont know if it was all necessary, but I had my Dad surface off the head sealing surface to make sure I didn't warp it...

    Might be a low tech way, but worked quite well..


  6. #6
    Join Date
    Jun 2006
    Calgary, Alberta

    Default exhaust manifolds

    heat the casting to a minimum of 350F, to bake out the oils and impurities, then let it cool. The weld repair can be done hot, with pre heating and cooling slowly, or it can be done cold. Due to the small cross sections of a manifold, it can be easily welded with Ni-rod or cast rods with little pre heat or post heat, so I will go with the cold method. Build a jig to hold the pieces in the right shape, then V-groove the joint 90 degrees, leaving a small root, 1/16" to 3/32", then grind the surface of the casting to clean up the porosity about 1/4" away from the joint. Use low heat, 60 - 80 amps for a 3/32 rod, and weld stringer beads, not more than 2 - 3 inches in length. Peen the weldment between passes, and let the casting cool between passes so you can touch it with your bare hand. The more peening during cooling, the better. Avoid weaving because it contracts the edges of the groove too much and causes cracking. I've used many different types of cast rods for repair, Ni Rod, Arctec supercast 80 and 90, Arctect cast 3, Certainium alloys, and another, Cronetron 211. Cronetron 211, as put, "the cast iron problem solver', is by far the best I've encountered in the past twelve years. Any of these electrodes will work, as long as they contain a sufficent amount of nickel. You want a rod that has a good elongation, so it doesn't allow cracking before you peen. Some electrodes are designed for hot cast welding, where temps are controlled for lengths of time, and some are more forgiving. After the joint is filled, you can grind the face reinforcement off and finish the weld repair with a needle scaler to give it a 'as cast look' which also relieves stress at the same time.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Warning: Function split() is deprecated in /mnt/stor3-wc1-dfw1/357822/357839/ on line 79

Welding Projects

Special Offers: See the latest Miller deals and promotions.