First Autogenous
RSS | Subscribe | Contact Us | Advertise | About Us
Results 1 to 14 of 14
  1. #1
    Join Date
    Mar 2007
    Location
    Under the Hood
    Posts
    353

    First Autogenous

    I do not post much but I sure read allot. Thought I would post my first attempt at autogenous stainless tube. I would like to get proficient enough to build a set of headers for my small block 400 and possibly pipes for my old Honda. The first weld was on the left and ofcourse the second on the right. I cleaned part of the second and left the colors on the remainder for reference. 304 ss .065 wall, Diamond Ground TriMix 1/16, #5 cup, 15 Argon, transformer machine at 75 amps, pedal and I set the pulse on the second weld at 10. It seemed to flow a little better. I did use filler for the first weld but only on a short stitch. I guess I need to cut this puppy open to see where I am at. I'll connect a purge soon,. Any comments???

    I see I missed a spot on the 2nd weld, will have to watch the closer.
    Attached Images Attached Images   
    Last edited by geezer; 09-14-2012 at 06:15 PM. Reason: Correcting content
    Geezer
    Power Mig 255C
    185 TIG
    Blue 175 MIG
    Ranger 8 Kohler 20HP
    1974 5K Lincoln/Wisconsin Powered (Cherry)
    Victor/Harris O/A
    K 487 Spool Gun

  2. #2
    Join Date
    Dec 2010
    Location
    SoCal-LA
    Posts
    4,760

    Re: First Autogenous

    Can you run your pulse up to maybe 100? Use a gas lens if you have one.

    Other than that, practice, practice, practice.
    "Nothing welded, nothing gained."
    Miller Dynasty700DX, 3 ea. Dynasty350DX, Dynasty200DX, ThermalArc 400 GTSW, MillerMatic350P, MillerMatic200 with spoolgun, MKCobraMig260, Lincoln SP-170T,PlasmaCam/Hypertherm 1250, Hypertherm800

  3. #3
    Join Date
    Mar 2007
    Location
    Under the Hood
    Posts
    353

    Re: First Autogenous

    Quote Originally Posted by shovelon View Post
    Can you run your pulse up to maybe 100? Use a gas lens if you have one.
    Dunno, ashamed to say so but I am not sure how many PPS the machine is designed for and the owners manual does not refer. I'll crank it up all the way tomorrow. Maybe I ought to "pulse" (no pun intended) the lincoln folks.

    Yup, I fully understand the practice sequence, just not sure how to get those stacked dimes affect without filler. This is new ground for me. thanks
    Geezer
    Power Mig 255C
    185 TIG
    Blue 175 MIG
    Ranger 8 Kohler 20HP
    1974 5K Lincoln/Wisconsin Powered (Cherry)
    Victor/Harris O/A
    K 487 Spool Gun

  4. #4
    Join Date
    Mar 2011
    Posts
    18

    Re: First Autogenous

    You will never have good results welding thin wall stainless tubing without a proper purge, unless you are looking for a very superficial, shallow penetration weld. Welded correctly with a proper purge, you won't get the "suck in/sinking" effect you are experiencing. Don't know what your pulse settings are other than 10 pps, but it is common when doing this kind of thing to run more like 2.5 pps.

    Gas lens is essential as well as practice.

  5. #5
    Join Date
    Mar 2007
    Location
    Under the Hood
    Posts
    353

    Re: First Autogenous

    Quote Originally Posted by wijo0131 View Post
    You will never have good results welding thin wall stainless tubing without a proper purge, unless you are looking for a very superficial, shallow penetration weld. Welded correctly with a proper purge, you won't get the "suck in/sinking" effect you are experiencing. Don't know what your pulse settings are other than 10 pps, but it is common when doing this kind of thing to run more like 2.5 pps.

    Gas lens is essential as well as practice.
    So the accepted PPS is 2.5pps on .065 304 tube? Ok, so I am a little heavy right now. I just checked my machine and the pulse setting goes from zero to 20HZ, assuming that is 20 cycles ps. So I need to adjust that to a point on the dial equivalent to 2.5. Yup, gas lens Monday, should have already had one but my stainless exposure/need has been minimal. Thanks
    Geezer
    Power Mig 255C
    185 TIG
    Blue 175 MIG
    Ranger 8 Kohler 20HP
    1974 5K Lincoln/Wisconsin Powered (Cherry)
    Victor/Harris O/A
    K 487 Spool Gun

  6. #6
    Join Date
    Dec 2011
    Posts
    283

    Re: First Autogenous

    Always, always you want to back purge with autogenous welds on thin wall stainless tube.

    I think a lot of the irregular appearance on your welds is due to heavy, uncontrolled sugaring on the backside, and secondly due to "suck back". Purging has the additional benefit as the slight amount of back-pressure supports the weld puddle and prevents suck back.

    This is how you want autogenous welds on thin tubing to look:
    http://weldingweb.com/showpost.php?p...5&postcount=19

    Note that sugaring means loss of alloy content in your beads and unpredictable weld chemistry,

    I don't have a lot of experience with pulsing. I've never found a need and all my pipe and tubing welding has been with traditional constant current. Also I can't think of any practical benefit with pulsing for autogenous welds- that's just my opinion and other posters my disagree.

    75 amps would be on the excessive side for non-pulsed. I prefer to slow the hell down and, reduce current and let a very small puddle develop, using as little current as possible. This takes a bit of trial-error to find the lowest current that can be used and still get full penetration.

    For gasoline exhausts grade 347 is pretty much required, at least for the headers. 304 is good for practice on, and you might get away with using it past the cat converter. But it will develop leaks and cracks in short order if you try and use 304 for the really hot and dirty areas.


  7. #7
    Join Date
    Mar 2007
    Location
    Under the Hood
    Posts
    353

    Re: First Autogenous

    Quote Originally Posted by Joshfromsaltlake View Post
    Always, always you want to back purge with autogenous welds on thin wall stainless tube.

    I think a lot of the irregular appearance on your welds is due to heavy, uncontrolled sugaring on the backside, and secondly due to "suck back". Purging has the additional benefit as the slight amount of back-pressure supports the weld puddle and prevents suck back.

    This is how you want autogenous welds on thin tubing to look:
    http://weldingweb.com/showpost.php?p...5&postcount=19

    Note that sugaring means loss of alloy content in your beads and unpredictable weld chemistry,

    I don't have a lot of experience with pulsing. I've never found a need and all my pipe and tubing welding has been with traditional constant current. Also I can't think of any practical benefit with pulsing for autogenous welds- that's just my opinion and other posters my disagree.

    75 amps would be on the excessive side for non-pulsed. I prefer to slow the hell down and, reduce current and let a very small puddle develop, using as little current as possible. This takes a bit of trial-error to find the lowest current that can be used and still get full penetration.

    For gasoline exhausts grade 347 is pretty much required, at least for the headers. 304 is good for practice on, and you might get away with using it past the cat converter. But it will develop leaks and cracks in short order if you try and use 304 for the really hot and dirty areas.


    Thanks Josh, good info. I see the thread you referenced used filler, anyway it is a good post, thanks. I set the welder on 75 but in action I never used full peddle, but your point is well taken, I can back off the heat. My 304 is a piece of scrap I picked up to practice on. As we proceed we will get more specific for the application i.e., 347. I'll read the post you referenced again and try again tomorrow. thanks
    Geezer
    Power Mig 255C
    185 TIG
    Blue 175 MIG
    Ranger 8 Kohler 20HP
    1974 5K Lincoln/Wisconsin Powered (Cherry)
    Victor/Harris O/A
    K 487 Spool Gun

  8. #8
    Join Date
    Mar 2011
    Posts
    18

    Re: First Autogenous

    What are your background and peak settings? If you want to see what a high quality autogenous weld looks like, just look into high purity/sanitary orbital welding a little bit. There is a fair bit of literature out there and you can get a good grasp on how to do it manually (which is also commonly done). Just remember, the behavior of the molten puddle is highly effected by the orientation of the weldment (1g, 3g, 6g, blah blah)

    Get the pulse settings set correctly, get your purge set correctly, and the only thing left is your technique (hotter than you think, faster than you think).

  9. #9
    Join Date
    Mar 2011
    Posts
    18

    Re: First Autogenous

    Quote Originally Posted by geezer View Post
    So the accepted PPS is 2.5pps on .065 304 tube?
    Yes, from what I'm familiar with; high vacuum/high purity plumbing and vessels. I would normally run around 2.3 pps

  10. #10
    Join Date
    Mar 2007
    Location
    Under the Hood
    Posts
    353

    Re: First Autogenous

    Quote Originally Posted by wijo0131 View Post
    Yes, from what I'm familiar with; high vacuum/high purity plumbing and vessels. I would normally run around 2.3 pps
    well thanks, I'll adjust the pps and see how it goes today. I see most have an inverter, I am dealing with a transformer machine Lincoln 185. More pics to come
    Geezer
    Power Mig 255C
    185 TIG
    Blue 175 MIG
    Ranger 8 Kohler 20HP
    1974 5K Lincoln/Wisconsin Powered (Cherry)
    Victor/Harris O/A
    K 487 Spool Gun

  11. #11
    Join Date
    Mar 2010
    Posts
    192

    Re: First Autogenous

    I respectfully disagree that the WIlliam McCormick thread posted above is what you're looking for.

    I would suggest you read this thread: http://weldingweb.com/showthread.php?t=116181

    for some additional information on fusion welding SS tube.

    Back purging is essential for a good serviceable outcome. Pulse, if used, should be low (2-3 PPS) or high (40+PPS) because between 3-40 the pulse is extremely hard on the eyes...

    Best of luck.
    Last edited by Mr. Moose; 09-18-2012 at 12:09 PM.

  12. #12
    Join Date
    Jul 2011
    Location
    Utah
    Posts
    1,412

    Re: First Autogenous

    Did this the other day.

    No purge.
    3" diameter, 304 stainless, .065" wall, autogeneous, 2 pps.
    No sugaring, no suckback, just some "mill scale" discoloring on the backside that came right off with a scotchbrite pad leaving shiney stainless.
    You can tell by the heat affected zone that it's not a superficial weld, plus I watched it fuse nicely.

    Last edited by MikeGyver; 09-18-2012 at 09:29 PM.
    Welding/Fab Pics: www.UtahWeld.com

  13. #13
    Join Date
    Jan 2012
    Posts
    162

    Re: First Autogenous

    When you are learning your PPS will be low, try 1-1.5. Try to match your weave with a pulse, meaning as you are zig-zagging allong, try to get a rhythm where each left movement has a blast, and each right movement has a blast.

    You could learn to do that by custom ordering your pulse as you see fit, with your foot, and turn off the pulser. Riding a peddle, keeeping time with a pulser, and managing arc length on small tube is allot to learn at once.
    Constant Current Weldor.

  14. #14
    Join Date
    Jul 2011
    Location
    Utah
    Posts
    1,412

    Re: First Autogenous

    Why would you zig zag?
    It's a single pass autogeneous weld, you want it as narrow as possible and with the least amount of heat input as possible while still getting the job done.
    Last edited by MikeGyver; 09-18-2012 at 09:45 PM.
    Welding/Fab Pics: www.UtahWeld.com

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
RSS | Home | Penton Media | Contact Us | Subscribe | For Advertisers | Terms of Use | Privacy Statement