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Help (!) ....About Welding......

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  • Help (!) ....About Welding......

    I'm wanting to buy a mig welder and know next to nothing about them. The various ratings are hard to decipher so.....

    when a welder with a DC 175 amp rating also has a (small print) rating of duty cycle: 16% @ 155 amps........what does that mean to me?

    There are so many of them on the market, both 115 and 230 volt models that I'm finding that I don't think I know enough to buy one. I'd want it for home shop use only and would want to weld mild steel 5/16" thick and aluminum sometimes. I have been able to pick up the various gasses and their uses as well as the difference between using gas or flux cored wire.

    Any hints will be given my full attention, and I'll appreciate any help at all. Thanks.


  • #2

    When purchasing a welding machine the saying "You get what you pay for" really comes into play. Stay away from machines that have Aluminum winding. Get one that uses copper for winding.

    Duty cycle is the amount of time that you can weld with the machine over a 10 minute period of time. So the 16% duty cycle would let you weld for 1.6 minutes during a 10 minute time period at the rated amperage.

    Welding aluminum required an AC machine with a high frequency unit. I use TIG when welding aluminum but it can be done with MIG.

    Study more before making a purchase and ask the questions you need an answer for.



    • #3
      I asked the same question about six weeks ago and got lots of good advice. (20-30 replies) Look that up and you'll find everything you wanted to know about little wire welders. Thanks-mike.


      • #4
        <font face="Verdana, Arial" size="2">Originally posted by WJHartson:

        Welding aluminum required an AC machine with a high frequency unit. I use TIG when welding aluminum but it can be done with MIG.

        I have an aluminum part on my boat motor welded with a mig. It looks like turkey poop. If you are looking for a good job on aluminum get a TIG.

        Someday I hope to afford a TIG for aluminum.



        • #5
          BTW, 20% duty cycle is probably ok for home use, but if used the welder a lot it would be a problem.

          Get a Miller, Lincoln, Hobart, or ESAB for serviceability. The cheap ones are not made to last, and the good ones aren't that much more expensive.
          The early worm gets eaten.


          • #6

            The higher the duty cycle rating the better the machine. Generally. A machine with a 50% duty cycle at 150amps is better then a 20% duty cycle at 150amps machine.

            If you want to weld 5/16 i think i can safely say that the 110v machines won`t handle it. It can be done but personally, and i do a fiar amount of welding, i wouldn`t trust it. Get the 220v, most likely a better machine and you can still do the small stuff with it.

            Aluminum with a mig can be done. You need some special things like a different liner for the gun, special wheels that push the aluminum wire, etc. I have a really good mig at work. We have the proper gas and wire for welding aluminum and i usually bring it to a shop to be done. It is just easier and cheaper that way. I keep all the equipment around because i never know when i will get called in at 2am to fix something.

            If you don`t have an arc welder then a mig is a great way to learn how to weld. Practice practice practice. A good guide line is if you are only going to do sheet metal i.e. 18 guage and up then a 110v machine will do fine. Anything lower, then 220v is the way to go. And buy a brand name. Lincon, hobart, miller, Esab, not because you will be able to get parts, but because most likely the guy selling it to you knows what he is selling. I don`t think the guy ar Wal-mart knows all the in and outs of welding???



            • #7
              My advice is get one with a 50amp 220vac requirement,it will have the power to weld .375" and thicker in multiple passes.Also get one with the big gas bottle they last a lot longer than the little ones,you must also get religeous about turning your gas off,it seems that the more expensive the gas the faster it leaks out.Find a local fab shop and talk to the guys there as well as your local welding supplier,gas mixes are also important many people prefer straight argon for aluminum some prefer mixed gas.One other thing is some people will tell you that a bottle of argon won't go stale but it will,this doesn't mean its bad it just means you need to lay the bottle over for a while and stand it back up,the reason being is that the argon will settle out in the bottom of the bottle and the impurities will rise to the top,I also remember being told that getting a mixture with a small amount of helium will make cleaner welds,hope this isn't to much info.
              I just need one more tool,just one!


              • #8

                I agree with you on getting in the habit of turning off the gas when not welding. The more expensive the gas the bigger the leak that can't be found.



                • #9
                  Ken, There's some good advice here. After thirty years of being in the business I'll just add (or ad to) a couple things.

                  Find a reputable welding supply house and tell the guy that's been there a long time what you want to do. If he really takes an interest, trust him.

                  The 110 machines aren't made for 5/16". It can be done, but if you're going to do much of it go for 220. You'll want something that will kick out 150-175 amps without breaking a sweat. A 200-225 amp machine with 40% duty cycle at that rating would be about right for a moderate amount of 5/16" steel. For aluminum, go TIG unless you're going into production.

                  If you're not really going to be doing that much 5/16", but will be more like sheet metal to 11 gauge (1/8") then there are some good 110v machines that will do what you want. Lincoln and Hobart make a couple of good ones.

                  There are two different kinds of flux cored wire. One for light machines with no gas and the other for heavier stuff - with gas. Even if you're getting a 110 machine, get one that takes gas. Stay away from flux core without gas.


                  • #10
                    To add a little to what has already been said - - Go to a welding supply store to buy the welder! The same guy that is going to sell you the gas and consumable parts. Lincoln makes good units but also have some low end welders that I would stay away from. The local welding supply store will not be selling these. I have Miller and Lincoln welders - - both work fine.

                    Good quality aluminum welding with MIG is possible with a spool gun ($600+) and a higher end machine with at least 19v output. The guy at the welding store can give you an explanation - - the guy at the hardware store won't have a clue.

                    If you are new to welding and want the most versatility go TIG with high frequency option for al. With TIG if you get a poor quality weld you can go over it without adding metal, with MIG you get out your grinder.


                    • #11
                      Great stuff! I do appreciate it, and best of all is being talked away from the 110 kits. I had looked at the little stick welders that Sears and others brought out some twenty or more years ago and rejected them then as inadequate to any use. But recently a guy I know told me about his new Lincoln WeldPac 100 and spoke of it as if it were the answer to all things, welding or otherwise. It got me curious, and I see that they've come a long way with the little wirefeed jobs.

                      But that duty cycle stuff threw me - I figured it had to be a limitation and suspected that it negated the claims so loudly advertized. It does,in many ways.

                      I bought a thin Haynes book on welding yesterday that lays it all out exactly in line with what you've all said, so I'm on hold doing research. At this point I'm thinking that more than one welder is the way to go - I saw the Lincoln AC 225 "tombstone" for $229. at a local Home Depot yesterday, and right alongside was the Lincoln "3200" 110v. 135 amp small mig for less than twice as much. They had none that uses 230 volts, but they're certainly available. I've got to think about how far I need to go with this.

                      I should apologize for asking the question, I think. Somehow it didn't occur to me that welding would be a much discussed subject in a machining forum but when I saw your post, mikem, I did a search and saw how foolish I'd been to think that way. As always in other areas there is a wealth of info already here. I've read most of it now.

                      Thanks All,



                      • #12
                        Hi Ken:
                        There is no need to apologize for asking questions. (about welding or whatever) The guys here answer them all, regardless of the quality of the inquiry. I hope I didn't make it sound like I was insulted by somebody else asking the same question, I just thought that there were some good responses to my earlier post that I really appreciated and that you would be interested in. From reading the answers here that you got here, it looks like you got some new ideas also.

                        Sometimes there are some questions posted here (mine included) that just don't make sense. That is the reason we ask--to benefit from the life experiences of guys that have "been there and done that". If the more seasoned metal heads here laughed at and put down every stupid question, this would be a boring website. The personality and info shown here is greatly appreciated and I would consider them to be friends, even though I have never met them.

                        After reading all the advice on the welders, I think that I'm going to get a Lincoln SP 175+. ( about $700) I found and bought a used plasma cutter and that has eaten into my welder funds, so it will be a month or so before I get the welder. Good luck on your search for a welder and keep asking questions. Thanks--Mike.


                        • #13
                          try, they have wholesale prices and free shipping. i just bought a lincoln power mig 200 for $1100 a few months ago. it was a couple hundred bucks cheaper than AGA. I told them how much i got it for when i went to get my contract/tanks, he told me thats about what he pays.(he was pissed, at least he got my gas biz) if you want to weld a lot of different metals from thick to thin, tig is the way to go, however being that it is the highest quality welding process, it is very very slow, and takes the highest amount of operator skill. if you are going to be welding mainly steel the mig is easy to use and very fast. i have both because i do a broad spectrum. something with a 60% duty cycle is considered the norm. lincoln claims that with a spool gun, the powermig can weld aluminum all day, and with the technology that this welder offers i would tend to want to believe them, all though i have no testimonial to that. i prefer lincoln the best, hobart, esab, and miller are also pretty good. i hope this helps

                          extreme tractor racing
                          extreme tractor racing


                          • #14
                            I was in the same boat awhile back and found a good local welding supply. Ended up with a Miller MIG 220v and have been very pleased with it performance. Before had only done gas welding so this was a bit of a change. Put an argon tank on it, read the manual, found some scrap aluminum and have been happily welding ever since. Finding a good local supplier is your best asset.



                            • #15
                              I have a 220 volt Lincoln mig with bottle. It works great but is a trifle underpowered. The gas used with it is called trimix. I found out when I was learning to tig that that means there is oxygen in it to make it hotter. I never would have thought that.
                              Welding together utility trailers, I use the mig for the not-critical items. I get out the (new) hobart stickmate and use it on the ones I would rather not see come apart. One of the first I tried to do with the mig, I took a hammer and knocked several welds apart. They looked great on the surface but did not melt in and fuse correctly. Not all were bad but enough to make me put the next pass on with a stick. But on sheet or thin stuff, no contest the mig is my love. It does stainless also with argon and stainless wire. Aluminum wire is so soft it bunches up in the feed roll of a mig, making a terrible mess like a jammed fishing rod, I know I have tried.
                              Welding takes time and skill to learn to do properly. Believe it or not, I am a better welder with a couple of beers in me. But it goes all to hell with a twelvepack. I think I take more time, I used to shoot pool like that too.
                              I am not as good of a welder as someone who does it everyday. We each have the things we are best at.
                              The best way to learn is to do it. Just practise before you start clipping car frames please. ( I sometimes buy and sell ).
                              Like most the other serious guys on here, anything I can do to help I will try.