how do I weld paper thin pipe?

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I have a good amount of chain link fence top rail available to me and thought I would make some small man-gates out of them.  However, I couldn't find a way to weld them together.  We have a flux-core machine with 0.30 wire in it now.  It's a small unit with hardly any variables besides wire spreed and voltage.I tried using it on a couple of different settings (I don't have a clue how to use this machine) but kept burning through the pipe.  The wire just sliced through the steel like a hot knife through butter.  There's a general usage guideline chart on the cover and I was pretty sure that this would do the job.  Sorry I don't have any information about the machine at the moment.  I can get it if needed.Any suggestions?Thank you.
Reply:I'm not a professional welder, but MIG alone would probably be too hot and flux-core is even hotter than MIG. MIG and flux-core are very similar, but MIG uses solid wire with nothing inside...If I was doing this project and had anything I wanted at my disposal, I'd use TIG. But you don't have TIG  You MIGHT still be able to do this though with your MIG machine especially if you have some solid wire, maybe something thinner than .30 but then you have to get new rollers and a new tip for the gun...For now, take some of the screwed/scrap metal, put your machine on a very very low setting, and remember that as you turn your amps down you must turn your volts down as well. Use two pieces and try to tack them together with just a quick hit of the trigger, I'm talking maybe a second at most. If it still blows through, bring you machine down some more. If you can get it to a setting that doesn't totally blow through it then I think you do this... If you got it set up right, you could do the welds in a pattern of small bumps of the trigger like I explained earlier. You're basically putting down some metal, letting it cool, putting down some metal, letting it cool, etc. etc...Do I think this will work? Idk for sure, which is why I said use the scrap metal. lol!! But it's worth a shot, I mean I'd certainly try it just for the heck of it.
Reply:Info on the machine could help too, but most MIG machines are pretty much the same as far as set-up goes. There can only be so many variables... But now I read back over your post and am wondering; you mean you're welding the actual pipes, not the chain links, right? And what material is the fence? If it's stainless you'd wanna get some stainless wire. If it's an aluminum fence that might be the main reason you're just blowing through it; you're probably using a carbon wire on aluminum, and aluminum doesn't weld to carbon. Which sucks -.- lol!
Reply:The fence is probably Galvanized sheet metal Pipe. It is very thin and almost impossible to weld.  By the time you get the zinc off it is almost gone. If you remove the zinc with muriatic acid, you may have enough iron left to weld.  It is the zinc that makes it so hard to weld with out destroying it.  Mac
Reply:Yes, it's very thin sheet metal, galvanized.  I wonder if a wire brush on an angle grinder will take off enough zinc?  But, muriatic acid is readily available at the local pool supply.I'll be going to the Ranch this morning and will get some info on the mig.I have been looking into getting another machine at the Ranch - we have the little mig and a Lincoln SA-200.  The Lincoln consumes copious quantities of gasoline and is a little expensive to run, especially since the idle doesn't work any more.  Also, not all of the projects I work on need something that big.  So, I thought a cracker box might fill in the gap.  The problem is that I wanted one that is 110 volts and inexpensive.  That limits the field a whole lot.  I also would prefer one that is DC but that makes the field even smaller.  So, I've been considering getting one that is AC, but have read mixed reviews on these so I'm back to doing nothing.  There are some out there with TIG attachments which I know nothing about, but am willing to learn.
Reply:Sanding/grinding-lightly, most of the zinc off, then throttling down the machine,doing short welds, stopping, brushing works with gal. tubing. Sanding inside ofthe tube-prior, helps.Gas Mig, 110 machine has a lower bottom end than a 220 volt machine, whichreally helps on thin. Fluxcore is a maybe-I don't mess with fluxcore.There's technique involved in working the puddle as the remaining zinc floatson top of it and flares off in the arc-takes practice.Real shops weld this stuff day in and day out, so ignorethe mis-advice by JMcL213 & Tool Maker.Blackbird
Reply:very carefully..   operator skill is the biggest part and that comes from practice.  having the right machine is the other part.  a real MIG  (metal Inert gas)  flux core is not MIG.  Preferrably something with an infinite voltage adjustment and not a tapped voltage.   there are some good tapped machines out there but they are not the cheap box store machines..Tiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:Originally Posted by mshearneYes, it's very thin sheet metal, galvanized.
Reply:Sorry I can't tell you how thin "thin" is.  I know the posts are heavier gauge, but the top-rail is thin enough to put a dent in it with a stick.  Don't know anything about gauges.  I know the machine that I am using says it will go down to 22 gauge.  But again, this doesn't mean anything to me.Speaking of the machine - it is a Hobart Handler 135 with two controls in the front, one is wire feed (10-100), and the other is Voltage (1-4 and purge).
Reply:Have used Pinnacle Alloys .035 E71T-GS  wire. Run  from a miller 301G and a 12 VS feeder.Made a hog trap from that type of fence material.Gasless wire, on 301G electrode neg, Volts 17 , wire speed 200 to 300
Reply:Check  AOC Welding Supply for Pinnacle Alloy wire
Reply:Thank you, I'll consider that.  But, it seems to me that the hogs around here would rip this stuff to shreds in no time.  Most of the traps around here are made of 1/2 rebar or something similar.
Reply:We line the trap with hog panel. I am located South West of you in Duval County, Benavides Area.  It works for us.
Reply:If you insert one pipe inside the other (male to female) it'll be easier to weld than a butt joint.  And since it won't be passing an inspection of sorts....weld it downhill!  If you weld it with the sa200....you should be able to crank it way down and weld it with 1/16 rods 6011 or 6013 Welding rods.........and far as the price of fuel...well you already saved money on materials, so it kinda works out.  Or buy a tig gun and hook it up to the sa200....or weld it with oxy acetylene and filler rod.....many different ways to do it.....
Reply:Joint design is important.  Butting 1/16 is difficult, but doable. Eliminate miters and cap ends.Sounds like a practice/learning thing.  I hate those mig machines that only have variable wire speed and voltage???
Reply:.023 wire wouldn't hurt either.  Remember with mig, there's gonna be a minimum voltage needed to burn a particular diameter wire and that of course will increase with wire type and diameter.  The output amps are related to the voltage and the WFS.   So you'd be able to feed more .023 wire and keep a puddle going with less heat input, less volts and less burn back.Not a pro, but I've read that mig brazing has alot less heat input, but not as strong.  You'd just have to change the wire, but I've read it ain't cheap.This is all assuming you can add gas to your small mig.  I'm not sure Fluxcore will run cool enough for very thin material.Guess you need to figure out if the investment in the ability to weld the pipe is really worth the cost you'll save from using the spare material.  You really need to actually measure the side wall thickness of the pipe to start.   Running a TIG off your SA200 would probably be your best bet, but it's not gonna be that cheap to set up.  Probably around $200 minimum between a torch, tank, adapter and regulator.Last edited by Drf255; 06-30-2013 at 06:20 AM.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:OK then,A couple of new ideas - oxy/acetylene, TIG on the SA-200, and 0.023 flux core wire.  Thanks.How strong of a weld would the oxy/ace give me?I've never done any welding that required gases.  Instead of buying a rig to do TIG on the SA-200, would it be reasonable to buy a $250 cracker box that did TIG as well as stick?  I know that the current would not be very high, but most of my work on the big welder is using 1/8" or 3/32" rods (usually 6011) at around 90 amps (which is the upper range of the first gear on my machine).  If I could find a portable unit that would provide 80 - 100 amps or a little more, with a reasonable duty cycle, be 110 volts, and offer stick and TIG....?  Maybe that will cost a little more to get all of what I want.That's two questions:  strength of oxy/ace weld and an economic cracker box.
Reply:Both the oxy-acetylene and cracker box welds will work fine.......I'm pretty sure the weld will be stronger than the thin diameter pipe.I was thinking about this last night on the way to bed.... if your going to spend $250 on a small machine to weld thin pipe......I would reconsider.  Depending on the amount of pipe needed for the gate project.....I would price regular schedule 40 pipe.....I bet you can get about 5-6 PCs of 20' for the money your going to spend on the cracker box....thou could probably get more material if you buy salvage or used pipe..........it'll be much stronger, you don't have to deal with galvanized, and you can weld it with the sa-200....On the flip side...having more tools is never bad!
Reply:In case anyone missed it, don't breathe that crap!-AaronJet 17.5" Drill Press1942 South Bend 16x84 Lathe1980s Miller 320A / BP --- 2013 Power Mig 2562012 Jet 7x12 Horizontal BandsawVictor O/A Setup
Reply:Originally Posted by mshearneHow strong of a weld would the oxy/ace give me?
Reply:True, I could buy the materials for that price, but I have 2" drill stem on hand and a lot of fencing pipe.  It's more of an excuse to get a new tool - but most of the repairs and work that I do on the ranch could be handled by a machine running under 100 amps.  Occasionally I can weld on a shredder, disc harrow or tractor part and I could use more power.  But light weight fencing, gates, and feeders could use a smaller machine.
Reply:If it's a excuse for another useful tool you need, I think you should be looking for the most versatile tool. A MIG/MAG welder will weld.A MMA welder will weld.A TIG welder will weld.A O/A set will weld, braze, cut, heat (for bending metal, removing rusted bolts etc.), light up the BBQ, and it can do all that without as much as an extension cord in sight so you can drag it along to some broken down equipment in the middle of a swamp. It may not always be the best tool for a job, but it's hard to beat how many diffrent types of job it does.
Reply:I've heard that welding galvanized steel is dangerous without really good respiration. Is it just the zinc layer, like if you take it off there's nothing else that'll hurt?
Reply:I welded thin galanized sheet metal in the 70s. We used a carbon arc sharpened in a pencil sharpener. Stuck that in the stinger and as I can remember we used straight polarity. We used silicon bronze. Everdure bronze. It is hard to find. Just so many welding supply stores handle it. You placed the bronze on the place to be welded and then touched the bronze with the carbon. Done a good job of welding and looked good. You dont have to grind off the galvanize just never weld without a blower on you. Boss told me if he caught me welding without the blower I was fired. Harold
Reply:Good to know - the foul smell should have told me something.  I'm a newbie, and I'll be sure to keep a fan on me when working with anything galvanized.Now, I am even more interested in O/A.  Gonna have to learn something new (love it).And versatility - yes yes yes.I found an Everlast PowerArc that will do stick, TIG, run on 110 or 220, has a duty cycle of 60%, and costs less than $300.  I can do low amp work on 110 volt and move it to a 220 if I need more current.  This one will go to 140 amps.  I have no clue what TIG needs.  I would not want to short sheet myself.Is that price straight from Everlast? $300 sounds pretty high for the PA140.Everlast PA160-STH... and that's about it!
Reply:I can get the 140 for around $250 (free shipping) or the 160 for $430.  That's a little out of my price range since I have a full grown welder available to me.  The 160 looks like a really nice machine and has a good review on line by Jody.  I hope the 140 will live up to it's bigger brother's name.
Reply:0.030 FCAW-S wire in an E71T-11 'flavor' like Lincoln NR-211-MP wire could be dialed down to about 30 amps at 50 ipm WFS and 13-14 V or up to about 140 amps at 300 ipm WFS and 18-19V.Remember the general welding rule-of-thumb: 1 amp per each 0.001 inch material thickness.  So some 1/8 inch material would (generally) call for 125 amps (more or less, depending on operator skill and technique and exact wire and welding position and joint type/configuration, etc).  16 gauge (0.060 inch thick, or pretty much 1/16 inch thick) would call for ~60 amps, etc, etc.Next, fit-up matters.  A lot.If you have a gap in the fit-up, especially with 'thin' material, you can easily blow a hole right through things.Regarding the zinc coating, a wire brush really won't remove it too well.  Grind (hard wheel or flap disk) it off, or remove with some acid (muriatic or even some plain vinegar will work.  Don't waste the good balsamic though, just use plain cheap distilled white vinegar.    )  'Thin' zinc coatings (as opposed to a thick and uneven hot-dipped galvanization) can sometimes be welding right through/over (the arc or flame if using O/A vaporizes the zinc), but joint configuration can sometimes 'trap' some zinc vapors (zinc oxide by that point/temperature, usually) and give you issues/problems with the weld.It's -never- a bad thing to clean your metal that you want to weld down to clean and shiny.  Sometimes, depending on the welding process and the welding filler being used, you can 'tolerate' various amounts of 'not-metal' when you go to weld, but cleaning things down to clean and shiny is never going to 'hurt' your weld or welding.Fit-up when brazing is usually even more important than when welding.O/A is certainly a useful tool, but a 'small' FCAW machine should be able to weld some fence top-rail using 0.030 NR-211-MP (or similar).Fit-up.  Very important.Yes, FCAW is usually 'hotter' than a similar GMAW weld (due to the current density because of the flux-core filling and the tube of actual metal wire that make up the FCAW wire).  But some 0.030 FCAW or some 0.023 or 0.030 solid GMAW should be able to weld up some fence top-rail.Welding 'thin' stuff is a bit tricky and takes some practice though, no doubt about it.  16 gauge (1.6 mm or 0.060 inch thick) is kind of right in-between most folks range between 'thick' and 'thin', but usually it's 'do-able' with some practice and getting decent fit-up (and dialing the welding parameters down to an appropriate level!).  The best laid schemes ... Gang oft agley ...
Reply:Thank you Moonrise, that's a lot of good information.  Being a newbie, the things that I should be able to do and the things that I can do are often pretty far apart.I took a piece of top rail and just tried to put a bead on it - right on top, not anywhere near a cut end.  I set the MIG to its lowest settings and punched a hole right through the pipe every time.  Wire speed didn't seem to make any difference.  As I stated earlier, I'm using a Hobart Handler 135 with voltage settings of 1-4 and wire feed control.  That's all.  The wire I'm using is 0.030 (something local).  I have not measured the actual thickness of the pipe.  If I think about it, I will do that this afternoon (if I have a working battery in my caliper).So, aside from my technique, I am assuming I have at least one of the three following problems:  wire is too big/hot, machine won't go low enough, or the pipe is less than 22 ga. (the limit of the machine).Thank you for the advice on technique - I need a lot more of that.  Seems to me there is as much art in welding as science.
Reply:Originally Posted by mshearneor the pipe is less than 22 ga. (the limit of the machine).
Reply:As luck would have it, my battery was still good in the caliper and I took half a dozen measurements and got a good average of about 0.05".  This would put it right in the range that you just mentioned.  Sure seemed to me that the piece I was working on was thinner.  I kept picking up pieces of pipe and thinking that they were thicker than I remembered.I think I'll try again, when I can find some time.Ordered the Everlast, so I'll probably not invest in smaller flux core wire.  I'll be moving toward supplies for TIG.Don't know anything about it.  Don't know what is going to come with the welder, or what other supplies I will need.  I do know that I will need some gas.  Wouldn't that be nice if I could find a bottle of Argon hidden away in the barn somewhere (maybe over by the long lost submarine...).
Reply:Didn't your handler come with a regulator / built in gas solenoid to run regular solid wire instead of flux core?I think your best bet would be to rent a bottle and try some .023 wire - going to gas shield instead of flux core helps a ton, and then the smaller wire helps even more.  I have a handler 140 and only run flux core when I need to do something quick and dirty and remote from my house, IE bring the machine and maybe the extension cord, no desire to move the massive heavy bottle any other time than getting a swap out.Tigging old galvanized pipe is kind of pointless as it will be slower and more difficult and the pipe as you say is pretty much free scrap.. And either machine would need a tank, so thats an inevitable cost anyways...miller syncrowave 250hobart handler 140home made 400 amp engine driven in progress...
Reply:Another way to fasten this stuff is using a CC (stick) power source, use a very small 1/8-3/16 Carbon Arc rod sanded to a point, and draw an arc, then braze with silicon bronze filler. I've done this on stuff .022-.025" thick. No need to clean off the zinc, this has been a way for HVAC guys to 'weld' stuff for a looooong time. Should give you a nice looking bead, and won't rust. But, .030"  flux-core should work on the fence stuff, I find it hard to believe it's less than 16 or 18 gauge (.062"-.049") disc-sand off the zinc, you'll be able to see where it's cleaned off pretty easily. Wire wheels don't usually work as well, they just smear the zinc around.If the welder has some sort of chart inside, try the lowest settings. Flux-core must be operated with straight polarity (electrode negative), compared to 'reverse' for MIG. That could be part of the problem.Dougspair
Reply:Dougspair - are you saying that I can do this with my SA-200, maybe set at its lowest current setting?  Is this like doing TIG, except using carbon instead of tungsten?Remember, I'm new to all this and have to look up a lot of the terms used here.  I like learning.