welding hydraulic cylinder rod to bracket...

Discussion in 'Shop Talk' started by texican, Oct 30, 2006.

  1. texican

    texican Well-Known Member

    Messages:
    12,327
    Joined:
    Oct 3, 2003
    Location:
    Carthage, Texas
    I've got a front end loader, and I broke the weld between the end of the cylinder where it's welded to the swivel bracket back, back in the summer. I cleaned it up, ground down all of the contact areas, and welded it back together with stainless rods. Well, it worked a good while, till I was gettin' a little brave and overstressed it and the weld broke again.... arrgghh!!!

    Should I use just a regular high strenth rod, or stick with the stainless rods?

    Anyone else have to repair their cylinder/bracket connection?
     
  2. aussie dave

    aussie dave Active Member

    Messages:
    38
    Joined:
    Apr 28, 2006
    Location:
    australia
    personally I would just use the high strength steel rods

    stainless rods have their applictions

    is the item/cylinder already stainless? if so the yes use it.
    is the item used with water (as in for a pumping cylinder) then yes use them.
    but if it ain't then why spend the extra cash for stainless
    (in oz stainless rods are 2 x price minimum of normal mild/ high strength steel ones).
     

  3. agmantoo

    agmantoo agmantoo Supporter

    Messages:
    10,854
    Joined:
    May 22, 2003
    Location:
    Zone 7
    The cylinder rod should extend through the yoke (swivel bracket) and probably the hole is worn oversized. The egg shaped hole lets the rod pivot thus breaking the weld. On the inside of the yoke do a 360 degree weld, on the cylinder side weld in two areas opposing each other for a length of 90 degrees each weld. If you weld a full 360 degrees on the cylinder side you could set up a stress situation and the end of the rod may snap. I would not use the stainless rod.
     
  4. dennisjp

    dennisjp dennisjp

    Messages:
    334
    Joined:
    Mar 2, 2006
    Location:
    Virginia
    I would use a 3/32 7018 and make several passes. Let each pass cool conciderably before making the next pass, and take an end grinder and clean it good before each pass.
    Put the last pass in the middle of the width of the weld to releave the stress.
    As Agmantoo said, the yoke may be worn and you may need to weld it up also, but if so, I would weld it up and then take it to a machine shop and have it rebored to the correct size for the cylinder rod.

    One more thing. Is the yoke steel or is it cast steel.
    If it is cast steel, I would preheat it before starting to weld, and let it cool back down to the same temp for each pass.
    Carry the part to the welding shop and they shound have a heat stick, (it is somewhat like a crayon, but they have different melting temps) and ask there oppenion of what temp you may need. Most shops will help you out like that for free, or maybe just the cost of the stick which is about 3 or 4 bucks.
    I welded a lot of 6" and 8" cast steel valves up on a powerplant many years ago while working on a shutdown, and I didn't know anything about this, and dang near every one of them busted out when they fired the boiler up, and it cost the company millions of dollars. Like to never got hired back on with that company.

    The reason for the preheat is to keep it from cracking from stress as it cools.
    Oh yea, if it is cast steel, after you have welded it, you need to let it cool slowly also.
    Just my two cents, Dennis
     
  5. texican

    texican Well-Known Member

    Messages:
    12,327
    Joined:
    Oct 3, 2003
    Location:
    Carthage, Texas
    I've got some 7018 3/32 rods... now if it'd just quit raining... now is one of those times when I need to have my barn electrified...

    thanks for all the tips...
     
  6. rambler

    rambler Well-Known Member Supporter

    Messages:
    8,323
    Joined:
    Jan 20, 2004
    Location:
    MN
    Was at my welding shop last month, dealing with a combine part. I said I have a welder, but don't always trust what I can do, so just brought him the pieces first....

    He started ranting (nicely) about the messes people bring him, & that when they use the wrong rod, the part is really messed up. If you choose the right rod the first time, most anything can be welded. But once the wrong stuff is on it, it's all mixed in & muddled, and can be difficult or impossible to get a good weld any more.

    I know nothing about welding, but I would not be using stainless rods for much of anything. Stainless is an odd duck, brittle, alloy, don't think one wants that melted in unless there is a _good_ reason....

    --->Paul
     
  7. dennisjp

    dennisjp dennisjp

    Messages:
    334
    Joined:
    Mar 2, 2006
    Location:
    Virginia
    I love to use stainless rods. They make the prettiest welds you can make, if you are a good welder and most things do fine with it, but some alloys won't mix.
    If you do use the wrong rod on something, grind it down to where the original metal was and then alittle further to get rid of the mixture and then build it back up.
    On some things you will need to be careful to make sure bolt holes etc., will still line up.
    For anyone trying to learn how to weld, or welding, (don't shoot me, Please) as a jack leg, (that is what they call me when it come to plumbing, and I am not sure I am that good, LOL) a 7014 is a lot easier to use than a 7018 is.
    Both rods is still 70,000 lbs.per.s.I tensile strength, but the 7014 can be used with ac or dc, something I forgot to say about the 7018. You have to have a DC welder to use it.
    If you are not an experienced welder, the 7014 is alot easier to use and still does a good job.
    I use a 7014 on nearly everything now because I can't see as good as I used to, and my nerves aren't up to par either, to get a good weld, and it is a lot more foregiving than the 18 is.
    I do think the 18 is stronger than the 14, but the numbers say they are the same. Been welding for over thirty years and no one has ever answered that question for me. From school in 1971 all the way thru nuclear power plants, and the men that all ways gave the welding test. :shrug:
    The 7014 was designed to work with AC welder, (Buzz Boxes), but they are wonderful for an old man that can't see good on a DC welder, LOL.
    Good luck, and don't forget the preheating if it is cast steel. "VERY IMPORTANT". and you don't have to have a heat stick. Use your judgement. Any amount of heat prior to the first pass will take most of the stress off the part, but a stick is best.
     
  8. texican

    texican Well-Known Member

    Messages:
    12,327
    Joined:
    Oct 3, 2003
    Location:
    Carthage, Texas
    I've already ground down to original steel on both parts. I've got several different boxes of sticks... if it weren't such a hassle getting it on a trailer down my muddy road, I could get any number of folks to do it... but I'm hardheaded and want to get er done myself... I have to Saturday to get it done, maybe the rain'll let it up a little between now and then...
     
  9. dennisjp

    dennisjp dennisjp

    Messages:
    334
    Joined:
    Mar 2, 2006
    Location:
    Virginia
    I think you would be better off if you used 7014's. They are way more forgiven than the 18's are. One more thing. When something like this breaks, it usually leaves a good bit of contact area that will not get penetrated by the weld. If you grind it closer to a point to form a larger V bevel along the crack, it will help.
    Run some beads over the top of it after you get it flushed out also, for added strenght. And run the last bead in the middle of the welded area for stress relief. Try to make sure there is more metal there than what was there to start with. After all, it was the full size when it broke the first time.
    Good luck, Dennis