Critique my welds please.

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I have only MIG welded for about a month now, and all I have managed to do is make a weld table and a few jigs. I have not concentrated on making better welds, till I had somewhere to work without hurting my bung back. So all the welds in my bench were done haphazardly without care. Now that I have that work bench I have done my 'First' proper attempt at learning to MIG.The steel used is just mild steel. The angle iron butt weld is about 2 - 3 mm thick, sanded and bevelled edge.The square tube is about 5 mm thick. The arrows in chalk are where I stopped and re positioned my hand. The rear weld of the angle iron has two arrows, this is where I tack welded earlier. (please ignore)Well ?? Are they any good for a novice ??  Is  there enough heat and penetration ?Appreciate feedback, negative or positive. I am here to learn.Thanks.Almost forgot.My MIG is a 210 amp, running on the low power setting. I am using a new spool of .9 mm wire, with a gas called 'Migshield' (Some sort of argon mix ??)[IMG][/IMG][IMG][/IMG][IMG][/IMG]Last edited by eyspy; 03-19-2009 at 10:33 PM.Reason: Forgot to add pictures ....
Reply:A little cold.  Also, it appears you might need to see the puddle better, because you are wandering off the joint.  Clean your hood or get a lighter shade or glasses.  When you stop and start again,  take time to just slightly back up the hill slightly and take a half a second or two to fill those craters that are left where you stopped.  It makes for a stronger and better tied together weldLast edited by lugweld; 03-19-2009 at 10:37 PM.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:pics?
Reply:Originally Posted by lugweldThose welds are must be good, I can't even see them...lol
Reply:From your description, they look great!   LOL  Where's the pics?MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:OKWeld # 2All the same piece, 5 mm thick mild steel, on the low power setting with the dial turned to #8How did I go ?[IMG][/IMG][IMG][/IMG][IMG][/IMG]
Reply:I mostly only do stick welding, and not top notch at that.Your last pic should tell you how much penetration you are getting.  Look at the boundary line between the weld and the parent metal.  It tells you how far the machine, at the setting your're running it at, will actually eat into the metal.It should also tell you the MOST IMPORTANT THING OF ALL.  Don't count on penetration to make up for a non beveled or gapped joint.  Except for a fillet weld(and sometimes those are beveled too), a butt joint should allow filler to contact as much of the entire profile as possible.  That's why it's called "filler".Your bevel, or I guess I should say the way I do my bevels, should be wider and if access is available from both sides of the plate, should almost penetrate the plate.  Leave yourself around !/8 inch of unbeveled material to mate the edges, and prevent burnthrough.  Grind a bevel on boths sides if possible.  BTW- a wider bevel gives you better shadow lines to follow to keep your weld on course.I get sorta fed up with "penetration" being used wrong.  The rod/wire will only penetrate so far.  Ultimately penetration is all about the grinder or the gap.  The grinder is a PITA, but use it.  You  won't go wrong.I'm not a pipe guy, and they do it different(I guess).  I can only tell you what I know.I don't know mm's from M&M's.  Sorry.  Try practicing on something around 3/16.  It will give you a better idea of how to set your heat.  Try to run hot enough where burnthrough is just a hair away.  It will give you an idea of how to set the heat on thicker metal.  You'll have a starting point.  It'll also tell you just how much your machine is capable of.  It'll make the grinder a good friend.  It's not about easy, it's about making something that won't break, and that you'll be proud of.Backside of a weld on thinner stuff should have an irregular, almost bubbly surface.  It means you almost burned thru the parent metal.  It should also have a very deep discoloration in addition to that.Until you figure out your machine, and the way you weld, start out hot, and work your way down.Well anyhow, this has been my experienceA note on shades.  While a lighter shade may make it easier to see where the weld is going, it sometimes makes the puddle harder to see.  You're only looking at glare in the puddle.  Darker shade can allow you to differentiate between the slag and the puddle(probably not an issue with MIG, dunno.  But don't always assume you have to go lighter)"Any day above ground is a good day"http://www.farmersamm.com/
Reply:way too slow or way too cold. practice your stops and starts.
Reply:Not bad.     Concentrate on holding the torch steady, pointing the wire into the joint center and moving the torch in a straight line.   On the changing hand position, try 'mapping out' your weld first, which means experiment with different hand/body positions by running the torch along the joint without pulling the trigger.   When you find a comfortable position that allows you to move through the whole joint without stopping to re-set yourself, then weld.   On longer welds where you will have to stop and re-start, do like Lugweld said and backstep onto the previous weld to fill the crater before taking off on the next weld.  If you start your wire at the tip of the crater, then make a half circle back around over the crater, it will fill it, then move forward with the weld.In butt joints, it's best to grind a bevel on at least one side and/or leave a gap between the pieces, on anything over 1/8" thick (that's about 3mm, I think).MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Excellent feedback, thanks.My bevels were about less than one 1/4 on one side only, and the material was butted up tight in the butt weld.It's a weekend here now and I have family stuff to attend, but next week I will take on all this good advice and throw up some more pics with what I have learned from you good people.Thanks once again.
Reply:Are the bands of rust I see surrounding the weld something created by the weld process,or were they just coincidentally present in the base metal before you started to weld?I would think the inert gas would prevent oxidation from occurring like that.
Reply:It was a VERY rusty piece of metal to start with. I just got stuck into it with the flap disk, but not 100%
Reply:Old rusty metal will have pits in it that contain rust, even after some extensive sanding, and when you weld on it, the rust particles will come to the surface of your weld bead as they should!When I weld on very rusty metal, as long as you can get to the joint with a grinder, I like to remove as much of the old rusty metal as possible, and then hit it with a wire brush and some compressed air to blow out the rust dust and anything that might be left over!Ken.#1. If you don't like what I wrote, or if it offends you, then don't read it!#2. I am living life the way I see fit, if you don't like the way I'M living, tough sh**!
Reply:OK, new week, new weld. Taken on board advice received and ready for new critique .These two welds are both on mild steel at 5 mm thick (approx 3/8")I beveled them about 2/3 the way through, and left a gap of about 1 - 1.5mmI cranked up the power on my welder from last week, and slowed down my travel whilst welding, creating a much hotter puddle.How do they look ??Too hot ? Too cold ? Just right ? Where do I need to improve ?Thanks......
Reply:They look good.  I think you need to revise your joint prep with less land depth (grind the bevel deeper, leave less metal un-beveled) and a wider gap cause it's not getting all the way down into the bottom of the root.   That and more heat.  Your torch control looks good.  MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Thanks. More bevel, wider gap, more heat. Post a new one up tomorrow.I thought weld 1 was slightly better than weld 2.
Reply:i will put some pics on but you want your wire a little faster and try to push in a straight push then stop and pull back and make your puddle wait for a circle then move on bout a half circle i will try to get some pics when i am at work tommorrow