0.030 mig wire in 0.023 machine (Linde)

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Hi I have an 80's vintage Linde 100 mig welder on which Ihave had to replace the gun (approx 5 years ago)with a tweeco mini-mig gun due to dry rot of the originalgunthe machine paperwork claims that the machine is*only* for 0.023 wire.   I would like to try some ofthat "twenty-gauge" wire which I believe is 0.030If I can get it to feed, am I doing the machine any harmby using it?Is the size limitation just the roller/drive?  if so I could make anotherone.The machine is real nice apart from being a bit dated. I don'twant to damage anything as replacement parts are extinct.Thanks,-Almus
Reply:Yes, if the gun and internal liner is only made for .023 then it will eventually tear, rip or ruin the liner. Also, if the drive mechanism only has a groove for the .023 then it may everntually wear out trying to push thicker wire. Take some pics and post, you might be able to run it if the mechanism is heavy duty enough.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:If the machine is made for 0.023 wire, then why don't you just use the 0.023/0.025 wire in it???Then you won't have any problems with the wrong gun liner or the wrong feed roller groove, etc, etc.
Reply:also, wouldn't the thicker wire require more amps to burn it?  ( just a thought )
Reply:Originally Posted by slamdvwalso, wouldn't the thicker wire require more amps to burn it?  ( just a thought )
Reply:Thanks for the (varied) advice.I was  just interested in trying some of the "twenty-gauge" wirewhich comes as 0.030".I realize that thicker solid wire requires more ergs to burn, butI am not sure that applies to the 20G stuff since it isn't solid.In fact, given that it allows welding of thinner material, onewould guess that it imparts less energy to the steel, andrequires less power to "burn". PlusI would guess that there would be some lee-way in myrange and wire feed settings to accomodate some variability.The idea is to weld even thinner stuff--so that is keeping meat the low range of my machine.I just wanted to try the wire without buying a new machine.I could easily turn a new drive roller.Perhaps I will just look for a cheap  0.030" gun and/or linerfor the  tweeco mini-mig that is on there, turn a spare roller.and have at it.Thanks again,-Almus
Reply:If the idea is to weld thin stuff, then why are you looking at using a thicker wire??   The smaller 120V 100A-class machines usually do -very- well on thin sheet steel with 0.023/0.025 wire.  That size wire in those machines with C-25 or other argon-CO2 gas blends (C-15, C-18, C-12, etc, etc) will usually do 24 gauge (0.024 inch thick) to 14 gauge (0.075 inch thick) steel very nicely.  Pure CO2 runs hotter and gives a little deeper penetration in steel than the argon blends, so it is harder to do thin steel with pure CO2 than argon-CO2 blends.Running 0.030 wire in the same machine will let you go down to only 20 gauge (0.036 inch thick) steel or so, mostly because you can only slow the wire speed down so far.  And a thicker wire at the same wire speed is carrying more amps than a thinner wire at the same speed.  And the machine still tops out at 14 gauge recommended max thickness (usually a machine amperage limit, not a wire limit).Miller has a process recommendation for wire sizes, wire speed, and amperage range on steel as follows:1 amp per each 0.001 inch thickness0.023 wire : 3.5 inch/min per amp : 30 - 90 A 0.030 wire : 2 inch/min per amp : 40 - 145 A0.035 wire : 1.6 inch/min per amp : 50 - 180 ASo if you want to do thin steel, your machine with the 0.023/0.025 wire is really what you want.  Don't even go to the bother of rigging 0.030 wire into your machine for thin steel.YMMV and IMHO.
Reply:Moonrise,Do a google search on the term"twenty gauge" welding wire. It isa special *non-solid* wire that isused like solid wire (ie with gas),and same polarity and allows youto weld much thinner  gauge steel (28g).It is made by Harris. See:http://www.harrisproductsgroup.com/p...enty_Gauge.pdf
Reply:I've never seen or used that Harris wire, but I haven't used all that many different wires.But the welding parameters called out in that spec sheet seem -WAY- out.  Sheet metal that is 28 gauge is only 1/64 inch or 0.015625 inch thick.  That is pretty darn thin stuff to MIG weld, and the spec sheet calls for 65-70A to weld that?!  Usual weld parameters for steel are 1 amp per each thou metal thickness (as I wrote above, per Miller's specs), so for 28 ga that would mean 15 amps.  I blew through the edge of some 16 ga steel (1/16 or 0.0625 inch thick) butt welds recently at around the recommended 60-70A using 0.025 L-56 wire and C-25 gas, mostly because the metal was getting hot by then and the edge was the end of the weld (the edge was tacked and other tacks were in place before the butt was welded).  I'd think that 65A applied to 28 ga sheet steel would make an instant hole!  I think that TIG, and an experienced TIG welder, would be the process to use on 28 ga.  Sheesh, that's thinner than a typical razor blade (look through the forums for the TIG guys welding razor blades).Your machine was made for and runs well with the 0.023/0.025 wire, I'd just use that.  Barring someone chiming in with experience with the Harris 0.030 wire.Last edited by MoonRise; 06-14-2007 at 01:38 PM.