Mig wire liner size

admin

Hello all, allow me to introduce myself. I am a young guy in north Texas who loves to build/fix stuff. I have been welding for about a year, starting with my Hobart Handler 135, which I picked up (with a "C" bottle) for barely a song. I was using .035 fluxcore for a while, till I got tired of paying $20 for just 2 pounds of the stuff. I got a big roll of .035 solid, and began using gas with it. I have been teaching myself (with much help from the internet and places like this) and have been gradually improving my skills.I also have a Lincoln Powerarc 4000 generator/stick welder, but that is not what my question is about. Recently, my friend bought a new (to him) car with a rusted out floorboard. He has another one that he would like me to weld in (first paying welding job!), but when I practiced beads on some thin sheet metal (22 ga I believe), I could not stop blowing holes. After doing a bit of googling and noticing the wire size vs. metal thickness chart, I realized that my wire size was WAY too thick for sheet metal. as a matter of fact, for my little machine, there is no point to using .035 (as opposed to .030) because I would never be able to max out the amps!What I am going to do in the near future is buy some contact tips and .025 solid wire, but my question (finally...) is this: Do I need to buy the smaller wire liner to use the smaller wire? According to the online manual, there are different size liners for .030-.035 and .025.I am fine with buying a new liner (actually, I need one anyway) because they are relatively inexpensive. I just have a curious mind and see this as a way to reduce a bit of work when switching wire sizes. Thanks in advance for your replies.Last edited by thecheese429; 03-31-2010 at 11:51 PM.
Reply:I would try the .025 wire with the liner you have before yanking it, just to know if it works or not. Go ahead and get a new liner, but check the online manual over very carefully and ask someone in your "local welding supply" store for the best all-around sized liner. 22 gauge is very thin and is only going to tolerate little-bitty-tacks all spaced apart to begin with. Gradually fill in the space between tacks as evenly as you can. That is about all you can do with a wire-fed machine on thin sheet.Welcome to the Machine. Attached ImagesCity of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:Thanks! I will be sure to do that the next time I am there. The metal may not have been 22 GA, but it was thin enough to blow holes.
Reply:I agree with the tack welding method for sheet metal, works good. Go slow and don't let it get too hot too prevent warpage.What year is the car? Floor boards are probably 18 or 20 gauge. Here's a pic of some welding I did on my firewall with tacks.
Reply:cheese,The 'little' MIG machines usually have one liner size for 0.025-0.035 wire.  Works fine.And yes, for thin sheetmetal some 0.025 solid wire and C25 gas work fine.Good luck.  Thin sheetmetal doesn't take all that much heat/amps to weld, and too much heat will warp it all over the place.  Small beads, and spread them out and allow the metal to cool off.  Repeat until it is all welded up.  The best laid schemes ... Gang oft agley ...
Reply:It is a 1976 Mercedes 240D. Between the German quality engineering and the age, I am sure the body panels are thicker than the sheet metal I will practice with. Here is what he is doing with it.Moonrise: When you say "small beads" do you mean to weld one inch here, move and weld one inch over there, then there, and so on and so forth? That makes sense to me, although it is good for me to hear it so as not to become overzealous and make one continual bead
Reply:Originally Posted by thecheese429It is a 1976 Mercedes 240D. Between the German quality engineering and the age, I am sure the body panels are thicker than the sheet metal I will practice with. Here is what he is doing with it.Moonrise: When you say "small beads" do you mean to weld one inch here, move and weld one inch over there, then there, and so on and so forth? That makes sense to me, although it is good for me to hear it so as not to become overzealous and make one continual bead
Reply:I would stick to little tacks until you get the hang of it. The metal will warp pretty quickly if you're not careful.
Reply:Originally Posted by SinisterI would stick to little tacks until you get the hang of it. The metal will warp pretty quickly if you're not careful.
Reply:Originally Posted by frogman68Sorry if my post wasnt clear thats what I meant a little tack in one corner go to another corner small tack etc..
Reply:Today I went to the welding supply store and got some .025 contact tips. I talked to the guy behind the counter, and he seemed quite knowledgeable. He said that "you're not really supposed to" use .025 wire with the bigger liner, but I probably wouldn't have any problems. I tried on the same sheet metal, and... WOW it was way better. I tried to take some pictures, but my camera doesn't do macro. The penetration was pretty good on the lowest voltage, with as much of a bead on each side. I tried some different stuff. First, I tried a stringer, but went too slow, and blew a hole. Then I moved faster, and it made quite a pretty bead. Then I tried just a series of tacks. That worked well, too. I tried a weaver pattern, but that blew through. I will probably do very small beads instead of tacks, because I don't know if I have that kind of patience. Also, I picked up a gold filter lens and gave it a try. I was not amazed with the vision I got. It was  by no means bad, but I kind of expected a little better.Last edited by thecheese429; 04-02-2010 at 04:33 PM. Originally Posted by SundownIIISometimes it's better to remain silent and be thought the fool, than to open one's mouth and remove all doubt.
Reply:I would go real slow. It's going to take longer to do if you blow holes and warp the metal.
Reply:The liner will be ok, use .024 carefully, the metal on those cars seems pretty thick about 18 gauge, I have never seen one that doesn't have rust on the rockers and quarter panels.Plan your splices well, I did one a while back and put the splice under the moulding and it wasn't a good idea because it was to hard to work where it had some warpage, should have done it where the metal was cherry again and access easy.