Wire feed / flux core question

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I just bought a Miller 211 mig welder. I am  building a truck flatbed and am using .035 flux core. It is welding very nicely but it seems to over heat the gun pretty quickly - after say 4-5 inches of weld. Also lots of crap build-up in the nozzle. I have been stopping to let it cool and clean it every 4-5 inches of weld. Also soon the wire starts hanging up in the tip. I just ordered miller's gassless tip for the gun (miller m-100 gun). I though that might hold less heat. I called miller and they said that the duty cycle of the gun with flux core is less (can't remember how much). I had a thought that may be crazy. What would it hurt if I ran a little compressed air through the machine, very low pressure maybe just a few psi, to help cool the tip and keep the crap out of the nozzle? Would it mess up the process too much? I can't remember my settings off the top of my head but I have it set as the chart recommends for 3/16 steel, 230volt operation. I guess another option would be to buy a higher amperage gun.I would appreciate any insight anybody has.
Reply:Most of the shielding for fcaw-s wire comes from the alloying additives, but some also comes from the CO2 gas generated while welding.  Using compressed air will blow this CO2 gas away and increase the chances of seeing porosity.  Likewise, running any kind of inert shielding gas will also throw off the chemistry of the weld deposit on a FCAW-S wire.  Your best bet is to step up to a heavier duty Bernard or Tweco gun.  I'm pretty certain you can order a gun from either manufacturer with the correct connector your your MM211.You can also just leave the nozzle off of your gas shielded gun while running fcaw-s wire.  Yes the duty cycle is lower with fcaw-s because gas shielded guns rely on gas flow for some of their cooling performance.Last thought, you might try switching to a different spool of wire.  Not sure what you're running now, but if it's those little 2lb spools of wire they can have a lot of cast and helix to the wire, which can contribute to wire feeding issues.  If you're running a generic brand of wire, you might also try switching to a brand from another manufacturer.  If the wire isn't well made, there can be feeding issues as well.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Thanks for the response. I figured there was probably a good reason not to put some air on there.I am using a 10lb spool of radnor wire. I was looking at some of those other guns and it does a appear that they will work on a miller. I will try some with my nozzle removed and see if that helps.
Reply:Yes try no nozzle.FCAW just runs hot by its nature. And its expensive, 1lb is like $13 and some of it burns off, but if you go with solid wire its 2lb from about the same price and not much burns off.old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:Man. You have a damn good machine. Go grab a bottle of CO2 and put the flux core crap in the trash.Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:Thanks guys. Burpee- I am thinking about trying co2. I actually have a 20lb co2 bottle. I need to get a different regulator though. The reg that comes with the welder is for the argon/mix tanks. Since I am just working on a flatbed body a little spatter is not much concern. Framework on the body is 3" and 4" channel.P.S. I just looked Mcmaster has a CGA 580 to CGA 320 converter. Looks like I should be able to put my regulator on my 20lb co2 tank with this.Last edited by pdeal; 04-21-2014 at 11:33 AM.
Reply:Originally Posted by pdealThanks guys. Burpee- I am thinking about trying co2. I actually have a 20lb co2 bottle. I need to get a different regulator though. The reg that comes with the welder is for the argon/mix tanks. Since I am just working on a flatbed body a little spatter is not much concern. Framework on the body is 3" and 4" channel.P.S. I just looked Mcmaster has a CGA 580 to CGA 320 converter. Looks like I should be able to put my regulator on my 20lb co2 tank with this.
Reply:Originally Posted by pdealThanks guys. Burpee- I am thinking about trying co2. I actually have a 20lb co2 bottle. I need to get a different regulator though. The reg that comes with the welder is for the argon/mix tanks. Since I am just working on a flatbed body a little spatter is not much concern. Framework on the body is 3" and 4" channel.P.S. I just looked Mcmaster has a CGA 580 to CGA 320 converter. Looks like I should be able to put my regulator on my 20lb co2 tank with this.
Reply:Wear thicker gloves! For gasless flux core you really need a gun designed for it. Lincoln's K-126 are really nice.You guys are hurting my feelings! I made a very good living running gasless flux core. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:I'm not hurting your feelings CEP.  For what the OP is doing I think gasless wire is a viable choice.  Starting with a quality product is half the battle.  But I think his Miller machine will self destruct if he plugs that Lincoln gun into it.  That is assuming you could even buy a Lincoln FCAW-S gun with a miller connector on it.  All that aside, as I sit here I am surprised that the OP only gets 4-5" of weld down before noticing a problem.  That's a lot of heat and spatter in a relatively short period of time; even for a light duty gun like the one that comes with the 211.Pdeal, do you have all your settings correct for the FCAW-S wire you're using?  Is your 211 setup for DCEN(or straight) polarity?  The work clamp should be connected to the (+) terminal inside the welder.  If this is reversed, it would cause poor welding performance and excessive spatter.How large are the welds your making where you can only weld 4-5"?  Are they fillet welds?  What position(Flat Vertical, Overhead) are you welding in?Something else doesn't seem right here...Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Miller makes flux core guns too. I understand they are cheaper than Lincoln guns. http://www.millerwelds.com/products/...ux-cored-guns/Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:I double checked and the workpiece is connected to the + and the gun is -. This is how the diagram showed for flux core. I am welding flat but in a corner- a fillet (flat piece to a vertical piece). One thing I am doing but maybe shouldn't is weaving it back and forth to get a big fillet. Seems to leave a nice weld to the extent that I am able to see and hold steady. I tinkered with it a little tonight without the nozzle. Not enough to see how it will hold up. I am going to swap out my empty co2 tank tomorrow and buy a 10# roll of solid core to try. I would like to get so I can use the flux core though since it really does do a great job for my current application. Seems like for structural steel type stuff it is the ticket.
Reply:That 20lb bottle will burn at least 10 maybe 15lb of electrode befor it need to be filled and it costs, what about $1 per pound of CO2.I have a 10lb bottle but it usually gets left on and have no idea how much leaks out.old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:Something is not quite right.   That machine should be able to burn fc nearly endless without overheating.  I have a comparable Lincoln and have never had it over heat and I push it as hard as it can go.  I assume you double checked that you have the right size tip?  I would be looking for the cause before you give up on the wire, it should run all day long assuming your not non stop welding.Farmer2Hobart Champion EliteMiller S-32p 12Lincoln sp175tLincoln 225 ac tombstoneHarris oxy/aceteleneMakita grinders/chopsawHypertherm Powermax 45
Reply:farmer2- I am using a .035 tip w/.035 wire. One thing i remember now, when I spoke to miller the guy did suggest trying the next size up- .045 I guess. I probably should try this. I will try a different type wire on my next roll.Thank you all for the ideas!Last edited by pdeal; 04-22-2014 at 08:47 AM.
Reply:What polarity are you running?old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:+ on the work and - on the gun
Reply:Just to follow up on this. I bought some .045 tips to try use with my .035 flux core wire and that seemed to solve much of my problem. No more wire sticking in the tip. Also, I got my co2 tank setup and bought some .035 solid wire and that is working well too and I suspect is about the same cost to operate as the flux core. 10lb of flux core wire was $60, 10# of solid wire was $32, fill of the 20# co2 tank was $20. Thanks again guys.
Reply:A 20lb cylinder should be able to burn that roll of wire as long as you remember to turn the cylinder off.Use the minimum gas to do the jobold Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder