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Thread: New to the site - welding for years

  1. #1
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    New to the site - welding for years

    Hello

    I have a Lincoln TIG squarewave 200 that has failed twice now in the 3 months since i bought it new. The repair shop cannot see why and say "It happens with these small TIGS".

    The reason I am joining this forum is to get enough information to buy a more trustworthy machine.

  2. #2
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    Dec 2013
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    Re: New to the site - welding for years

    Quote Originally Posted by Alodine View Post
    Hello

    I have a Lincoln TIG squarewave 200 that has failed twice now in the 3 months since i bought it new. The repair shop cannot see why and say "It happens with these small TIGS".

    The reason I am joining this forum is to get enough information to buy a more trustworthy machine.
    I wanted to TIG in 1970. It was a secret process in the GE plant at the time. Many years later, the technology was no longer secret. I approached two different Airgas managers in two different towns. Second one was full of good news. He sold me a Miller Diversion 180. I'll never forgive him for that.

    I now have a Miller Dynasty 280DX, it hasn't as much power as I wish it had, otherwise it is perfect.

    There are 100 features to consider in a TIG machine.
    I start with aluminum. Do you want to weld aluminum? The lucky people who first welded aluminum used as their shielding gas, only helium. Their experience was utterly different from yours. Manufacturers have tried to build welders equal in performance to the primitive ones used then.

    Welding steel is a different matter than welding aluminum. Steel works on DC, a steel welder is less complex than aluminum.

    Aluminum uses AC current. Heating the work happens mostly in the electrode negative half cycle. Cleaning the oxide layer happens only in the electrode positive half cycle.

    An arc doesn't happen except in ionized atmosphere. Ionization is imbalance of electrons in atoms. Shielding gas doesn't conduct electricity unless it is ionized.

    If ionization must begin, it needs a concentration of electrons on a surface to ionize gas building a "bridge". Ionization happens easily in the EN half cycle. The pointed electrode is clean. In the EP half cycle electrons build up on a bigger surface & oxidized aluminum is less conductive.

    Early welders used sine wave AC. Current tapered off to zero before the change in direction. Re establishing ionization for the arc in EP half cycle was a struggle. Cleaning cycle was less effective. They introduced High Frequency, an overrunning secondary flow of higher voltage, low current, higher frequency. It helped to preserve ionization for better conductivity of gas.

    Eventually, square wave was introduced. Direction of flow is so suddenly reversed ionization isn't lost. Now we can balance EN to EP flow to optimize welding.

    Most important on my list of features in an aluminum welder is amperage, then duty cycle, then wave shape. After that there are many specifications to consider, service being big! A welder that doesn't work is a boat anchor.
    An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.

  3. #3
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    Re: New to the site - welding for years

    Welcome!
    IMPEACH BIDEN!
    NRA LIFE MEMBER

    UNITWELD 175 AMP 3 IN1 DC
    MIDSTATES 300 AMP AC MACHINE
    GOD HELP AMERICA!
    "Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety. BENJAMIN FRANKLIN

  4. #4
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    Re: New to the site - welding for years

    Welcome Alodine!

    Quote Originally Posted by Alodine View Post
    Hello

    I have a Lincoln TIG squarewave 200 that has failed twice now in the 3 months since i bought it new. The repair shop cannot see why and say "It happens with these small TIGS".
    Not exactly what I would call a statement to inspire confidence in a customer. Sheesh.

    Quote Originally Posted by Alodine View Post
    The reason I am joining this forum is to get enough information to buy a more trustworthy machine.
    Hopefully you'll find the advice, opinions and pros and cons here. Lots of voice, lots of choices. A few posts on how people have repaired their SW200s. A couple questions to ask: Are you happy with the setting/options available on the 200, or do you want more choices? Also, what is your budget? And is this for home/hobby or professional use?

    I'm pretty sure the answers you provide will help sort through all the options out there and refine the advice you'll get.
    Dave66
    =================
    Millermatic 211 (Transformer Based)
    Primeweld TIG 225X

  5. #5
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    Re: New to the site - welding for years

    You will find the only advice saying buy cheap, you'll love it comes from dealers of Chinese welders.
    My experience was; buy name brand bottom of the line, I hated it.
    Get lots of advice from everyone willing to talk, every real welder said Syncrowave. At the time Sincrowave was in production, just under $5000 without cooler or other essentials.

    I didn't yet understand all the other specifications important. I bought a Dialarc 250HF, a great old school welder. I later learned if I could feed it helium it was designed for I'd love it. Sine wave, fixed at 50% EP, fed Argon it wasn't the best welder.

    My third is a Dynasty 280DX. At the time it was new to the market. I couldn't believe a lunch box sized welder would make Syncrowave obsolete! I love it, but want more power. For now, I have a precious little tank of helium, It is like nitrous to a dragster! It makes my 280 amps feel like 400 amps.
    An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.

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