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  • #31
    Originally posted by Evan
    I do use flux core. It spatters and you use twice as much wire that costs twice as much money to do the same amount of welding. It doesn't make as nice a weld and the flux must be completely removed before painting. Other than that it's fine.
    I don't find that it spatters a significant amount more than bare wire with co2.
    Given the choice, I usualy choose the flux core over the other processes available to me at work for what I do , it is faster.
    I will not dispute Your point about cleaning befor painting but is not a problem, everything that gets inspected needs to be wire wheeled or the inspector gets pi$$y. Stuff that does not require an inspection gets preped for paint by the painting contractor or if it doesn't need paint it doesn't get cleaned .
    As far as weld bead cosmetics , flux core looks just as good or better than bare wire ....for me any way.
    I guess it comes down to personal preference, and not having a co2 bottle at home gives me more room for other junk .

    Steve

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    • #32
      So far my limited experience with mig vs flux core is that the mig is much more controllable when welding thin wall tubing. I do a lot of that. My iron work gates and railings are largely constructed of thin wall tubing so that they don't weigh a hundred pounds per yard. Plus, I have a reliable source of decent quality thin wall square tubing shorts that average 4 to 6 feet long and cost me nothing. I don't know how fuel gas exhaus will compare to argon/CO2 but I think I will find out. I'll start with something very simple just as a test to see if it is worth proceeding. In fact, I just had an idea....

      Back in a bit.
      Free software for calculating bolt circles and similar: Click Here

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      • #33
        Originally posted by andy_b
        i'm just wondering, now that CO2 is considered a toxin in the US, would a CO2 generator be classified the same as a mercury generator or a dioxin generator? i wonder if i'll need a hazardous materials transport permit to take my CO2 bottle to be refilled.

        andy b.
        Pardon? CO2 considered a toxin? Stop making stuff up. It's a pollutant - a resource in the wrong place.

        - Bart
        Bart Smaalders
        http://smaalders.net/barts

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        • #34
          I just did a very quick and dirty test. This may be enough to make me reconsider spending any more time on this idea.

          The three beads on the right were laid with no shielding gas, just mig wire.

          The three beads in the centre were done with gas on.

          The three on the left were done with the gas off and the tail of a propane bottle torch flame playing over the puddle. Yuck.

          Free software for calculating bolt circles and similar: Click Here

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          • #35
            Thanks for the update Evan, and showing us the results of your research.
            Interesting, I would of thought that the weld beads without any shielding gas would have been the worst.
            What kind of shielding gas was used on the center beads?

            Although I have this information at home in print, I thought I would share this site for those that need a a comprehensive guide to shielding gas characteristics and their applications.

            http://www.thefabricator.com/Consuma...le.cfm?ID=1702
            Home, down in the valley behind the Red Angus
            Bad Decisions Make Good Stories​

            Location: British Columbia

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            • #36
              The shielding gas is standard argon 75%/CO2 25%

              I am going to try again with a little bit more sophistcated setup. Since the flame was impinging on the weld it may be a problem with highly reactive atomic oxygen present in the flame. When I have time I will run the flame into a can and take the exhaust gas from there. One may speculate all day what will happen but until it is actually tried nobody really knows.

              I have another idea to try as well.
              Last edited by Evan; 07-05-2009, 04:19 PM.
              Free software for calculating bolt circles and similar: Click Here

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              • #37
                Also turbulence from the flame may be drawing atmosphere into the weld zone.

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                • #38
                  try running an IC engine on propane ..and use the exhaust ..

                  a ic generator would do ..all you have to do is run a pipe into the air intake and they will run ..

                  all the best.markj

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                  • #39
                    Originally posted by kvom
                    My 20# CO2 tank costs me less than $20 to refill.
                    I was at the local HF store yesterday and noticed they have 20 cu ft argon and CO/2 bottles. They seem quite small - is that a good way to go? Seems very limiting, but I've never tried gas with my MIG. They were certainly cheap - I assume they are empty when purchased.

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                    • #40
                      That is what I have. I had a spare oxy B bottle and had it re-valved for argon. It cost less than half what a new tank would cost. The valve cost $45 and the fill was about the same. It seems to be lasting pretty well.

                      The thing that surprised me is how much longer a spool of wire lasts. It's about half the price of flux core and lasts twice as long. I just bought a 5 kilo spool of .025 mig wire for $40. It's Lincoln brand, I hope my Miller doesn't decide to pout.
                      Free software for calculating bolt circles and similar: Click Here

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                      • #41
                        I just bought a spool of the ni-rod flux core stuff. Shipping weight is 30lbs so I think that's more than I'll need in a lifetime. When is your star party?

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                        • #42
                          Originally posted by dp
                          I was at the local HF store yesterday and noticed they have 20 cu ft argon and CO/2 bottles. They seem quite small - is that a good way to go?
                          No. It costs trivially more to fill a larger bottle with any gas, and you'll run through those little "burglar bottles" in under an hour. The welding gas suppliers are mostly charging you for the overhead, and not the gas.
                          "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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                          • #43
                            Originally posted by Evan
                            That is what I have. I had a spare oxy B bottle and had it re-valved for argon. It cost less than half what a new tank would cost. The valve cost $45 and the fill was about the same. It seems to be lasting pretty well.

                            The thing that surprised me is how much longer a spool of wire lasts. It's about half the price of flux core and lasts twice as long. I just bought a 5 kilo spool of .025 mig wire for $40. It's Lincoln brand, I hope my Miller doesn't decide to pout.
                            Yep,solid wire is a better deal all the way round.

                            On the gas problem,several years ago I needed a c25 bottle and the then only show in town would not lease a bottle without a good credit rating(I haven't borrowed any money in years so I didn't have a rating).

                            My solution was to use my own bottle and buy gas off a local weld shop.Two argon fittings on each end of a short piece of hydraulic hose was all I needed to transfer to my bottle.My bottle was the same size as what they used (175cf) so they just charged me for half a bottle +$10 for they're trouble.A full bottle ran 1900psi so I ended up with 900# give or take,enough to burn a 11# roll of .030" ER70 with a little left over.

                            Maybe talk to a local fab shop?
                            Last edited by wierdscience; 07-06-2009, 11:05 PM.
                            I just need one more tool,just one!

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                            • #44
                              I'm also surprised by how clean the bare wire beads look.

                              What machine did you do that with, and what were your settings?

                              If you try that over 100A, you end up with what looks like bird chit.

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                              • #45
                                I'm also surprised by how clean the bare wire beads look.
                                Why? Gas welding doesn't have any better shielding than just the combustion fumes. I have done a lot of O/A welding over the years and I tend to use the same technique with the wirefeed. I did some more tests without gas and the weld beads are almost respectable. It runs sort of hot without the gas but the main thing is that it doesn't flow out like it does with flux or gas. Still, it would work in a pinch even without gas.

                                The three beads on the right are at different voltages, no gas. I have a Miller 135.

                                The next bead to the left was done in a rich propane atmosphere with the mixing ports on the torch taped over. Blecch.

                                Further to the left are several beads that were done with the metal first painted with borax. Also not good. What I haven't tried yet is reversing the polarity. That may make a major difference.

                                Free software for calculating bolt circles and similar: Click Here

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