Miller Electric

Welding Discussion Forums

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

Page 1 of 2 12 LastLast
Results 1 to 10 of 15
  1. #1
    Join Date
    Feb 2007
    Location
    Olive Branch Ms
    Posts
    129

    Default Backup gas for Stainless

    I was asked to repair a piece of stainless trim for a guys hotrod yesterday. It was really thin. Someone had tried to mig it and butchered it. I cut out the damage and put in a patch. It worked out good. I did not use any backup gas though and the underside of the piece did'nt look so good. I need to find some backup gas plates. They don't seem to be easy to find. I called Indiana Ox. no luck, No luck on e-bay. If anyone knows where to buy some let me know. I may just make some.

    Monte, I don't know if this will help your shiny/dull question but something I have started doing that seems to help is to make a quick lower current pass over the first couple of inches that I am going to weld. It seems to do two things. Preclean and preheat. Then back to the start and punch the pedal. The best welds that I get seem to be the ones where a good puddle forms quickly. Works for me anyways, Adam
    Webb's Welding and Repair LLC
    MM210 w/a 3035 spoolgun
    Syncrowave 250
    Spectrum 625
    Trialbazer 302 w/HF
    http://webbsweldingandrepair.com/home

  2. #2
    Join Date
    Mar 2007
    Location
    Deltaville, VA
    Posts
    2,239

    Default

    Jet,

    What you're experiencing on the backside of the weld is called "sugaring". Very common when welding thinner SS.

    You're making too much of what constitutes a "backing plate". Basically all you need to do is create a "gas dam" for your purge gas (generally Ar). It can be fabricated from nearly anything. I have used sheet copper or aluminum flashing to create a gas pocket on the backside of the weld. Alum flashing works well, is cheap, and is easy to conform to the shape you need.

    You will need a second bottle of Ar and a separate regulator (or one of the dual output flowmeters).

  3. #3
    Join Date
    Aug 2006
    Location
    near rochester NY
    Posts
    9,881

    Default

    dose it have to be argon as a backer or could you get away with strait Co2 ? if your argon spair runs out and Co2 is all ya have on hand use it or wait till you get more argon ?
    thanks for the help
    ......or..........
    hope i helped

    feel free to shoot me an e-mail direct i have time to chat. james@newyorkmetalart.com
    summer is here, plant a tree. if you don't have space or time to plant one sponsor some one else to plant one for you. a tree is an investment in our planet, help it out.
    JAMES

  4. #4
    Join Date
    Mar 2007
    Location
    Deltaville, VA
    Posts
    2,239

    Default

    100% CO2 is the LAST thing you want around a SS weld.

    You want your purging gas to be an inert gas. CO2 is a "reactive" gas.

    Although CO2 is used in very small quantities in tri-mix (2 1/2%) it is definitely not recommended for a purging gas for SS.

  5. #5

    Default

    What about using a flux on the back side like Solar Flux instead of messing with the gas? Wouldn't that be much easier?

    Craig

  6. #6
    Join Date
    Nov 2006
    Location
    Lake of the Ozarks MO
    Posts
    3,593

    Default

    Quote Originally Posted by SundownIII View Post
    100% CO2 is the LAST thing you want around a SS weld.

    You want your purging gas to be an inert gas. CO2 is a "reactive" gas.

    Although CO2 is used in very small quantities in tri-mix (2 1/2%) it is definitely not recommended for a purging gas for SS.

    On tig

    Forney mig wire even says co2 on 308L wire right on the box (100%) ...or at least they used to... so I tried it one day and it worked just fine. Not saying it's the best by any means but they said it and I did it.

    www.facebook.com/outbackaluminumwelding
    Miller Dynasty 700...OH YEA BABY!!
    MM 350P...PULSE SPRAYIN' MONSTER
    Miller Dynasty 280 with AC independent expansion card
    Miller Dynasty 200 DX "Blue Lightning"

    Miller Bobcat 225 NT (what I began my present Biz with!)
    Miller 30-A Spoolgun
    Miller WC-115-A
    Miller Spectrum 300
    Miller 225 Thunderbolt (my first machine bought new 1980)
    Miller Digital Elite Titanium 9400

  7. #7
    Join Date
    Aug 2006
    Location
    near rochester NY
    Posts
    9,881

    Default

    i thought the pass port used Co2 for stainless, thats why i thought maybe it could be used as a back gas when TIGing.

    as for holding the back gas in place i have used tin foil taped to the back to make a chamber around the back of the weld. maybe not the best option, but it worked.
    thanks for the help
    ......or..........
    hope i helped

    feel free to shoot me an e-mail direct i have time to chat. james@newyorkmetalart.com
    summer is here, plant a tree. if you don't have space or time to plant one sponsor some one else to plant one for you. a tree is an investment in our planet, help it out.
    JAMES

  8. #8
    Join Date
    Nov 2005
    Posts
    107

    Default

    On little jobs I use this http://www.weldhugger.com/ but sometimes you have to make your own. They aren't cheap but pretty universal. Backshield with argon

  9. #9
    Join Date
    Mar 2007
    Location
    Deltaville, VA
    Posts
    2,239

    Default

    Dang BVWELD,

    Neat little tool, but they are mighty proud of them.

    I can buy a lot of aluminum flashing and duct tape for those prices.

    Thanks for posting though.

  10. #10
    Join Date
    Nov 2005
    Posts
    107

    Default

    Quote Originally Posted by SundownIII View Post
    Dang BVWELD,

    Neat little tool, but they are mighty proud of them.

    I can buy a lot of aluminum flashing and duct tape for those prices.

    Thanks for posting though.
    Don't forget the Reynolds Wrap You think thats high, price purge bladders

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/www.millerwelds.com/web/content/lib/footer.inc.php on line 82

Welding Projects

Special Offers: See the latest Miller deals and promotions.