Re: [Amc-list] possible welder purchase info

[Frank Swygert <farna@xxxxxxx>]

Marty, for occasional hobby work that you describe that welder would be adequate. You'd want to use the thinner of the two wire sizes for sheet metal, and it can be used for thicker material. A 110V wire welder is fairly easy to learn to weld with, and will weld up to 1/16" with little prep work. To penetrate 1/8" (the max the specs say the welder is good for) requires welding a bead from BOTH sides or grinding a bevel in the ends first. You could technically weld much thicker material by beveling, it would just take a long time to fill in the bevel with multiple welds. The duty cycle means basically that you can weld continuously for x minutes (the percentage) out of 100 minutes. You typically want to weld sheet metal in 1/2"-1" runs, skip at least that much, then weld again. So you aren't welding a continuous bead, so the duty cycle is fine. Sheet metal would weld best on low, things like the battery tray and support on high. Even welding thicker 1/8" material it's best to 
 run in 1-2" beads then stop for a second or so, so the 10% duty cycle is fine. 

Now a word about flux core. As the name implies, there is a flux inside the center of the wire. This acts as a shielding gas as it burns, but it doesn't do a very good job. Most construction codes will not allow the use of flux core welders. A slag is produced that gets embedded in the weld causing weak spots and small pits (voids) in the weld. This isn't critical for most hobby applications, and the voids can be welded over and filled. The weld isn't pretty though, a lot of grinding is needed to smooth it out. For welding sheet metal this isn't always necessary -- a few voids won't weaken the weld much, and the weld will be smoothed over with filler. 

A true MIG welder uses a shielding gas. The gas shields so much better and makes a much nicer looking, cleaner weld with few or no voids with a little practice. There will likely still be some grinding needed, but less than half of what's needed for a flux core welder. It's hard to get good results from a flux core wire no matter how good you are. 

A cheap machine with a similar duty cycle and amp range as the one above would sell for around $180-$250 (from HF or Wal-Mart -- they carry a Campbell-Hausfeld for around $250). Of course there are better, more  expensive machines, but for occasional hobby work the cheaper one will be fine -- I have a Campbell-Hausfeld. Of course you then need to buy a $100-$150 gas bottle and have it filled, or rent one from a local welding supply. Renting it usually isn't practical, as they expect you to refill it a lot and charge a monthly fee ($10 or so) whether you use it or not. I have a bottle on mine that hasn't been filled in three years -- I don't weld a whole lot since finishing my main project (which was partially done with flux core wire). 

Even if you can't afford the welder and bottle now, you'll be ahead of the game to buy a welder that will accept a bottle or flux core wire. Then if you decide you want the bottle you'll be able to simply add it. The cheap flux core machines don't have this option. You have to change the polarity of the machine as well as have the internal valve and hose for gas. To switch from gas to flux core it's simply moving a wire in the machine then switching the welding wire -- the gas hose can be used. HF sells unfilled bottle too, but check the local welding supply for the price on a filled small cylinder. You want an argon/CO2 mix -- tell them it's for a 110V wire welder and they'll know what you want (I forget the percentage mix). 

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Date: Thu, 12 Mar 2009 12:52:48 -0700 (PDT)
From: Marty Bricker <mbrickerusn@xxxxxxxxx>

I've never done any welding but would like to do some.  That being said, HF has a Chicago Elec 90 amp flux wire welder for sale for $88 (reg $150).  Specs are: .030 or .035 wire, duty cycle 10% @ 80 and 18% @ 60 amps, 63-68 amps (low) and 79-90 (hi).  None of this really means anything to me so I have no idea if this is good for anything.  I was looking to do things like small rust repair patches, possibly filling in small holes in sheet metal where badges were mounted.  Repairing/replacing things like battery trays, etc.  Thanks for any input/advice.

-- 
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)


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