Aluminum weld with Spool gun ?

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OK got the new spool gun for the MM211. The welds look good but lots of black soot on outer edges, is this normal?Using spray metal arch process, 4043/.030, I have the regulator for 100% argon set to to 20 CFH, the manual says 20-30 cfh. This was done on 1/8 practice plate stock. Haven't started on the 6061 as of yet, just got the gun late today just ran a couple beads before leaving.Also bought a jar of nozzle gel and have not used this for the aluminum for fear of weld contamination. Should I use this on all material or not?Thanks,KarlLast edited by badvette; 03-13-2012 at 12:48 AM.Clausing 5914Bridgeport J headMiller Syncrowave 250DXHypertherm Powermax 65Quency QT-5 80 gallonHorizontal bandsaw
Reply:Hello Karl, I would save the nozzle gel for other applications, not the aluminum. A few considerations for your aluminum welding: do you have any prior experience with GMAW on aluminum? and are you using a forehand progression (pushing the weld with your gun)? I ask about your experience so that you don't take comments that are made to be considered as looking down upon you. I ask about the weld progression because it is the most generally accepted practice to use a forehand progression when welding aluminum with wire, although there will be times when you may need to deviate from this. Those times will result in changes in the bead profile and how much "soot" that you see. If you have an opportunity take a look at www.millerwelds.com, there are a number of really great resources  on there that can give you some great tips on how to get started using your spool gun on aluminum and likely other tips with machine settings, techniques and additional tidbits of information. Good luck and best regards, Allanaevald
Reply:Originally Posted by aevaldHello Karl, I would save the nozzle gel for other applications, not the aluminum. A few considerations for your aluminum welding: do you have any prior experience with GMAW on aluminum? and are you using a forehand progression (pushing the weld with your gun)? I ask about your experience so that you don't take comments that are made to be considered as looking down upon you. I ask about the weld progression because it is the most generally accepted practice to use a forehand progression when welding aluminum with wire, although there will be times when you may need to deviate from this. Those times will result in changes in the bead profile and how much "soot" that you see. If you have an opportunity take a look at www.millerwelds.com, there are a number of really great resources  on there that can give you some great tips on how to get started using your spool gun on aluminum and likely other tips with machine settings, techniques and additional tidbits of information. Good luck and best regards, Allan
Reply:Hello again Karl, actually the DCEP current is what enables the "cleaning" portion of aluminum welding with GMAW. Somewhat in the same sense that the DCEP part of AC current has a cleaning effect with the GTAW process on aluminum. You spoke of your nozzle to work distance, you may wish to close that distance just a little bit, maybe more in the 1/2" to 5/8" range. This may accomplish a couple of things: reduction of the possibility of turbulence or the venturi effect that might cause contamination of the weld pool from atmosphere that is drawn in and less wander of the wire due to cast. If cast seems to be an unknown term it is what describes the curling of the wire as it exits the contact tip due to the wire being wound on a spool and during the feeding process these loops tend to effect feed steadiness. Shortening up the distance can help to reduce the movement experienced. You mentioned that you felt as if you were achieving "spray transfer" as the wire appears to be burning off above the weld puddle. Now experiment a bit with the wire feed speed and voltage, take note of how the finished bead looks. This next comment is geared towards fillet welds, flat welds will not quite fit this next description. Meaning: is it tied in nicely at both toes? is the profile of the weld face concave, flat, or convex? All of these characteristics can have their purposes, yet, a concave profile can sometimes be prone to cracking with certain types of loading or vibration. Flat or slightly convex are often more desirable. When considering beads done in the flat position, voltage and wire speed will also be a consideration that can be altered to meet your needs when considering various thicknesses. Too little voltage coupled with too little wire will likely yield a bead that is narrow and flat. Too little voltage and too much wire will likely yield a bead that is narrow and stands up considerably above the base metal and doesn't appear to tie in well at the bead toes. Too high a voltage with too little wire might yield a wide bead with little build up and possibly some burn-through on the backside of your weld bead. Too high a voltage and too much wire might yield a lot of burn-through as well as possibly a few holes and might appear rather flat on the welded side in the places where burn-through has not been experienced. Proper voltage and wire speed will likely yield beads that are tied in nicely at both toes, have a slight to noticeable back-side appearance of penetration, and have a slightly convex bead profile on the welded side. Additionally you will need to consider travel speed as another consideration. The consideration of travel speed, voltage, and wire speed along with gun angle can all be components of a successful and well purposed weld bead. Good luck on your new "toy/tool" and enjoy getting used to it and using it. I know that there are plenty of others on the forum here that can give you additional information to help you out. Best regards, Allanaevald
Reply:Originally Posted by aevaldHello again Karl, actually the DCEP current is what enables the "cleaning" portion of aluminum welding with GMAW. Somewhat in the same sense that the DCEP part of AC current has a cleaning effect with the GTAW process on aluminum. You spoke of your nozzle to work distance, you may wish to close that distance just a little bit, maybe more in the 1/2" to 5/8" range. This may accomplish a couple of things: reduction of the possibility of turbulence or the venturi effect that might cause contamination of the weld pool from atmosphere that is drawn in and less wander of the wire due to cast. If cast seems to be an unknown term it is what describes the curling of the wire as it exits the contact tip due to the wire being wound on a spool and during the feeding process these loops tend to effect feed steadiness. Shortening up the distance can help to reduce the movement experienced. You mentioned that you felt as if you were achieving "spray transfer" as the wire appears to be burning off above the weld puddle. Now experiment a bit with the wire feed speed and voltage, take note of how the finished bead looks. This next comment is geared towards fillet welds, flat welds will not quite fit this next description. Meaning: is it tied in nicely at both toes? is the profile of the weld face concave, flat, or convex? All of these characteristics can have their purposes, yet, a concave profile can sometimes be prone to cracking with certain types of loading or vibration. Flat or slightly convex are often more desirable. When considering beads done in the flat position, voltage and wire speed will also be a consideration that can be altered to meet your needs when considering various thicknesses. Too little voltage coupled with too little wire will likely yield a bead that is narrow and flat. Too little voltage and too much wire will likely yield a bead that is narrow and stands up considerably above the base metal and doesn't appear to tie in well at the bead toes. Too high a voltage with too little wire might yield a wide bead with little build up and possibly some burn-through on the backside of your weld bead. Too high a voltage and too much wire might yield a lot of burn-through as well as possibly a few holes and might appear rather flat on the welded side in the places where burn-through has not been experienced. Proper voltage and wire speed will likely yield beads that are tied in nicely at both toes, have a slight to noticeable back-side appearance of penetration, and have a slightly convex bead profile on the welded side. Additionally you will need to consider travel speed as another consideration. The consideration of travel speed, voltage, and wire speed along with gun angle can all be components of a successful and well purposed weld bead. Good luck on your new "toy/tool" and enjoy getting used to it and using it. I know that there are plenty of others on the forum here that can give you additional information to help you out. Best regards, Allan
Reply:Hello again Karl, sometimes soot can also be related to type of wire. 4043 generally will yield a "cleaner" weld and 5356 can display more soot. Just a few other items. Regards, Allanaevald
Reply:Originally Posted by aevaldHello again Karl, sometimes soot can also be related to type of wire. 4043 generally will yield a "cleaner" weld and 5356 can display more soot. Just a few other items. Regards, Allan
Reply:I would get a lot more Soot using the MM211 over the Passport Plus- same spoolgun, same Argon.It may just be the nature of the MM211Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge