Critiques wanted.

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I am practicing welding for a rocker panel modification on my Jeep ZJ.  I have a "bent beyond repair" rear hatch that I am using for practice.I welded around one of the hinge plates to practice joining metals of disimilar thickness, or thinness as it were.Millermattic 180.  .024 wire, 25%-75% mix.I did a cursive "e" and lingered a bit on the thicker hinge material on the two "better" looking runs. The run on the left edge (#1) was contaminated with paint.  #3 is just a disaster.I have some thoughts but would like input from people who know what the hell they are doing before I make any changes to my settings or technique.This last pic is just a different angle of $4Thanks in advance.Last edited by skeletonizer; 09-27-2012 at 04:26 PM.Gorilla tapeZip tiesJB weld
Reply:This kind of lap joint where you weld thicker metal to thin is especially troublesome. Overall it looks decent. That hinge isn't going anywhere. If possible, check the back side of the panel to see if you have adequate penetration.what size nozzle are you using? I suggest you increase gas flow to 20 cf/ hrWithout seeing the back side I'd say that the settings you're using are adequate. they may be slightly low. #2 and #$ are what you want to see. #3 is ovbviously way to fast and way too cold.I advise against trying to weave/oscillate on materials this thin.  IF you feel like you need to use a weave that means your settings may be wrong.Concentrate the arc on the thicker metal.
Reply:Number 2 is great, 3&4 are cold, but it looks like all will work. What did you chage from 2 to 3 and which was first?
Reply:#2 was laid down first.  #3 my travel speed was too fast IMO.I think #4 is the best weld (a poster on garage forums agreed).  #2 lacks penetration on the panel.All four are the same settings.  I made changes only with my technique.Gorilla tapeZip tiesJB weld
Reply:Originally Posted by A_Pmech#1  Unclear#2  Wire speed and travel too high, unfused toe, "arrows" in the bead.#3  Not enough heat, unfused toe.#4  Correct weld parameters, fused toe, slightly convex weld, semi-circular bead undulations.In a lap weld penetration is unimportant as there's nothing to penetrate.  The full thickness of the lapped piece should be welded along with some slight reinforcing cap.  There should be no unfused toe on the lapped section and full fillet length should be at least the thickness of the lapped material.
Reply:Like joshfromsaltlake said, you shouldn't have to use a weave motion or cursive e on metal that thin, those techniques are for welding thicker metal. It looks like you have to adjust your technique until you get it right, and I would suggest not using the autoset feature, sometimes its better for beginners to use a lower wire feed setting, cuz they can't maintain control on a fast/hot setting. http://www.philswelding.com
Reply:your setting for 22ga seems a little wrong to me that should be the thickness of the sheet metal correct? the hinge is probably what 18-16Ga? i would pick a setting inbetween the two, and concentrate the heat into the thicker steel and let it wash down onto the thinner steel. your talking about thin sheet metal, the apperance of the weld really means more than the penitration. 22ga is only about .02 of an inch thick how much penitration can you really have? run it a bit hotter and get the weld looking great and you should be fine holding the steel together.Offering CNC Plasma cutting and welding projects.Follow me on facebook https://www.facebook.com/nobigdeal.fabSupport those that support WW.
Reply:A little practice for the bench I am going to build.  I have ordered 2"x2"x1/8" tube for the bench.The place I ordered from had no scrap for me to practice on nor did two other places in town so I bought a two foot chunk of angle from Tractor Supply to practice on. Let me know if you think these look good enough for a welding table.  They seem a bit cold to me but when I try to add more heat things just seem to go to hell.Two joints to approximate the tubing I will be using.Millermatic 180, 25%-75%, .030 wire.  Voltage 4.5, wirespeed 55.  Pushing with about 1/2" of stickout.  First one:Gorilla tapeZip tiesJB weld
Reply:Second Joint:Gorilla tapeZip tiesJB weld
Reply:Looks ok to me, but your way too high on the vertical side of the joint. Your weld when viewed from the end should be close to a triangle. The weld you have here is not fused at the bottom toe very well, but I have a feeling it's because of bead placement in the joint. As the top toe looks to be fused well. If your running out of materials just veep welding them together, worst case cut them apart and keep going. The freeze lines in the weld are showing a nice consistent travel speed that looks to be right, (they have a nice curve to them, and are not too pointy indicating moving too fast.Try keeping the nozzle at a 45 degree angle to the weld joint and pay attention to it, to keep it there I have a feeling your letting the mig gun drop and it's causing your bead to climb up on the vertical side of the joint.Offering CNC Plasma cutting and welding projects.Follow me on facebook https://www.facebook.com/nobigdeal.fabSupport those that support WW.
Reply:Originally Posted by NoBigDeal FabLooks ok to me, but your way too high on the vertical side of the joint. Your weld when viewed from the end should be close to a triangle. The weld you have here is not fused at the bottom toe very well, but I have a feeling it's because of bead placement in the joint. As the top toe looks to be fused well. If your running out of materials just veep welding them together, worst case cut them apart and keep going. The freeze lines in the weld are showing a nice consistent travel speed that looks to be right, (they have a nice curve to them, and are not too pointy indicating moving too fast.Try keeping the nozzle at a 45 degree angle to the weld joint and pay attention to it, to keep it there I have a feeling your letting the mig gun drop and it's causing your bead to climb up on the vertical side of the joint.
Reply:One more thing where are you located? I have plenty of small scrap pieces, and I'm looking to haul it off, I have 22ga through 1/2 inch. All are small drops from my CNC plasma, but they would be great to weld as lap joints for practice. If your local (not likely) I would gladly hand it over for you to play with, as it's not enough to be worth much as scrap, (maybe $20-30) but would offer up a bunch of hours of practice welding.Offering CNC Plasma cutting and welding projects.Follow me on facebook https://www.facebook.com/nobigdeal.fabSupport those that support WW.
Reply:skeletonizer...I like the equipment list on your sig line...no WD40?
Reply:Originally Posted by NoBigDeal FabOne more thing where are you located? I have plenty of small scrap pieces, and I'm looking to haul it off, I have 22ga through 1/2 inch. All are small drops from my CNC plasma, but they would be great to weld as lap joints for practice. If your local (not likely) I would gladly hand it over for you to play with, as it's not enough to be worth much as scrap, (maybe $20-30) but would offer up a bunch of hours of practice welding.
Reply:Originally Posted by shortfuseskeletonizer...I like the equipment list on your sig line...no WD40?
Reply:I am just a hobby weldor, but from my one mig class I would call the 2nd batch of pics pretty cold.  When the bead sticks up that high I would try for more voltage and adjust wirespeed as needed to keep the arc singing right.  I have never used an autoset, maybe you can just choose the next thicker setting and give that a try.miller syncrowave 250hobart handler 140home made 400 amp engine driven in progress...