need help selecting a welder to do auto body work

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I have a big ac/dc buzz box that I ahve used for years. I am getting ready to start a project cutting out some rust holes in my truck and welding in rust panels. I know Ideally I would use a tig, but I cannot afford a decent tig nor have the skill to use one. I am eyeballing a hobart handler 140 at sears, and would get a 75/25 bottle of argon / co2 to use with it. Does this rig sound like it eill be capable of doing what I need?
Reply:I have a HH140 and it works great on autobody sheetmetal with .023 wire and 75/25 mix.Good for filling small holes.  Good fit up of replacement/patch panels is essential. Weld a short stitch at a time and don't let the heat build up.  Buy a 220V machine if you can swing it, you'll be glad you did.GalenHH140 & TA185 Thermal Dynamics Cutmaster 52Smith O/AEaton compressor27 yrs USAF enlisted/retiredtoo many projects in progressgoing back to school
Reply:how about this guy?http://www.lowes.com/pd_256723-1703-K2481-1_0_?productId=1072947&Ntt=mig%20welder&Ntk=i_prod  ucts&pl=1&currentURL=/pl__0__s?newSearch=true$Ntt=mig%20welder$y=0$x=0
Reply:wrong locationLast edited by transit; 02-11-2010 at 04:36 PM.
Reply:Originally Posted by transitThe problem is there is no one formula. The over head beam [ I beam] is suspended at the ends with the load anywhere, middle or near one end. The beam will tend to sag, so we need stiffness. The load will most likely be hoisted and move along the beam by a trolley riding on the beams bottom flanges, the flanges need to be able to carry the load or bend. The end supports for the beams are columns, the longer and the thinner the column, the more likely it will buckle, complicating the column loading is twisting. All the welds must be capable to carry all the loads at the joints. If you plan on 600 lbs. the rated load should be 1,000 lbs. and then you need a safety factor, no less than 3 x 1,000 lbs.Forgot, live load and dead load. Now its getting complex, if you weld two 1/8 “ plates, T joint, that carry 1,500 lbs that try to slid the leg along the top of the T with ER70S-6 how long must the beads be?
Reply:Originally Posted by cutlass1972I think you got the wrong thread.
Reply:For autobody repair a decent quality 110v wire feed machine will work great. A 220V machine will work fine two, and give you more options for future work, but for sheet metal 110v works great. A TIG machine has a greater likely hood to put in too much heat and warp sheet metal. I really like Lincoln's wire feed machines.
Reply:OK, I ended up coughing up the money to get the Lincoln 180. Now I need to buy a gas bottle. I have no feeling whatsoever how long a 40 cf or 80 cf tank would last me. Can someone give me an idea how fast I will use up gas? I am planning on going straight argon, and I am thinking of going with an 80cf bottle.
Reply:Well, think of what you'll be setting the gas flow meter to on your bottle. For mig I think it's 20 cubic feet an hour. 40 cf tank will give you 2 hours of actual welding time. That's time your machine is burning wire. 80 cf would be 4 hours. Keep in mind that most of the job is prep, fittup and clean up. The time you actually spend welding is fairly short in comparison.In general though it's best to get the biggest bottle you can because refill fees are based more on the handling of the bottle than on the amount of gas in it, so a 40 cf tank is going to cost almost as much as a 80 cf tank to fill.I would also recomend getting the mixed gas.
Reply:Originally Posted by Grimm1I would also recomend getting the mixed gas.
Reply:cutlass,Plain argon is used for TIG on pretty much everything.  Sometimes an argon-helium blend is used for big/thick stuff.For MIG though, plain argon is used for welding aluminum or copper or anything OTHER than steel.  Or again, sometimes an argon-helium blend for big/thick stuff.For MIG welding on steel, plain argon is NOT used.  Somtimes plain CO2 (welding grade) is used, sometimes various blends of argon-CO2 (most common would be C25 for short-circuit transfer like you would be doing on sheetmetal) or argon with 1-2% of O2 for spray-transfer on stainless steel, or sometimes an argon-helium-CO2 Tri-Mix for small machines on stainless steel.Read up herehttp://content.lincolnelectric.com/p...ture/c4200.pdf  The best laid schemes ... Gang oft agley ...
Reply:excellent! Thank you!
Reply:Thanks again Moonrise, this is excellent info. I am still reading and will need to reread a few times to let it all sink in. It looks like I will be welding on steel that is about 19ga (1.11125 mm) so I will want to weld using the short circuit technique (GMAW-S) using .025" solid welding wire and a gas mixture of about 80% argon and 20%co2 or 75% argon and 25% co2.How does this sound so far?
Reply:MIG on thin sheetmetal is where 0.025 solid wire and C25 shine.    Welding (or trying to weld) heavy plate with that stuff would be a bad idea though.  Want more info?  Try here http://esabna.com/us/en/education/index.cfm  and also http://esabna.com/us/en/education/esab-university.cfm especially the MIG Welding Handbook section.If you aren't in North America, go to www.esab.com and pick the appropriate region on the map.You can also read more at the Lincoln site www.lincolnelectric.com or at the Miller site www.millerwelds.com.    The best laid schemes ... Gang oft agley ...
Reply:i'd have to say the Lincoln 140C with Diamond Core..........Hands down......game over ...Endno other choice............miller , far second.        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3