MIG on Thin Steel

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I will be purchasing my first MIG in the next few days.  I've narrowed my choice to either an HH187 or a PM180C.Occasionally I will need to weld 24Ga (.025") steel.  Which of those two machines is more likely do a better job / be easier to operate on thin material?Lincoln offers a Spot Weld Timer.  When would one use that?  How?Thanks in advance for any suggestions.Tom
Reply:The spot timer may not be too important.  It would allow you to precisely control the arc duration and hence spot weld size, but most people probably do ok by just manually working the trigger and judging arc time.
Reply:Never heard of the PM180C before and hobarts are not common where I live. Any brand name mig welder is going to do the job with no problems the big thing will be how you do it. When dealing with thin sheet metal I prefer a 110 unit over the 220. I know that the 220 units turn down to the same as the 110 units but I find that the 110 does a better job. This is just my opinion and how I do it. Get the welder you want and learn how it will work for you. I may tell you something and it may not be what works best for you. Someone may tell you this welder is better than that welder and you may find the opposite. I know that you can eliminate allot of problems by asking question of people who use and own welders. Thats the good part of the forums. I plan on getting the miller DVI as it has the 110 and 220 volt amp ranges and will do all that I need. Hope this helps and good luck on your purchase.Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:I'm not familiar with the machines you mention.... but as Pluser has mentioned the sot timer isn't really something you you need to bother with. Especially if it is an extra cost._________________Chris
Reply:The most important thing will be to use the thinnest mig wire you can get-like .023. Then, practice..
Reply:Like Rojodiablo said, thin wire and practice. I use .025 in my Lincoln sp135 and it does a great job on 24ga. as long as you controll the heat properly. I loaned the welder to my brother to do some 18ga. for a project he was working on and of course since he's older he felt that my advice on heat was worthless and he melted through everything as a result.I like to tack everything together with the tacks spaced at about 1.5 inches apart, then let them all cool. Double check the allignment of the peice, and continue welding, I use tacks, for lack of a better term, for the entire peice. My welds have full penatration as the durration is a little longer than an actuall tack weld. I do 2-3 next to each of my original tack welds then move on, keep going with this cycle and allowing them to cool dow a little bit before adding more. If warpage is not a huge concern, replacing floor panels that have lots of bead rolling in them for instance, you can move much quicker.Any modern mig will do this, like Jamlit, I prefer my 110volt Lincoln because it's so easy to set-up and use. Most of the thin material I do is autobody work so I don't need to wast time tig welding when I can mig, only to grind down the welds and hopefully never see tham again.
Reply:OK.  Thanks to all for the suggestions.Because nobody suggested otherwise, I went with the less expensive HH187, which was only $650 from Northern Tool, including the free hood and free shipping.  So, in about a week, I'll be practicing.I found a number of copper bars in our junk bin, so I'll try making some heat sinks to back up the thin metal.  If I discover any intesting method, I'll share it.Tom
Reply:In my attempts at welding thin metal, I had a lot of trouble with the weld going to one side or the other of two pieces butted together. I was using flux core wire. I was repairing a hood on my car - since I was using flux core I ended up with kind of a sloppy weld that I repeatedly welded, then grinded, welded, grinded, etc. For now I have it smoothed with a skim coat of filler and some primer. Later, I found that I had much better control using gas and thinner, solid wire with electrode positive. I used pure Ar but you can try other gases and see what you think.Somebody on here named David R ingrained that in my head:Bare or solid wire = ELECTRODE POSITIVEFlux core = ELECTRODE NEGATIVEI'm pretty amazed at the increased control when welding with gas. http://www.weldingweb.com/vbb/showthread.php?t=9154So, when my garage is finished, I will re-finish that hood with this technique. BTW, I'm using a Hobart Handler 140 (110V) if that helps.Hobart Handler 140 MIGHypertherm Max 43 Plasma CutterA Bernzomatic Torch, and some solder.
Reply:Tom,From everything I've read regarding those two machines you've made the wise choice.  The 187 has an extremely smooth arc and wonderful bead characteristics.  It will do thin sheet with the best of the 110 migs and from what I understand; better than most.If you wish you might visit the Hobart Weldtalk forum and search for threads on this model or just pose a question when you have one.  The members there embrace all brands and recognize their virtues and faults.  In the end the right machine helps a lot but won't eliminate the need for the skills of the person operating it.You're gonna love it,Clay