Welding thicker metal to thinner metal.

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I picked up a trailer similar to the one pictured. It was in rough shape; I sanded, repainted and put new wheels/tires on it. I had traded it for a leaf blower with a blown engine, so my investment is pretty small. I also fitted it with a 1 and 7/8th coupler so I could tow it behind my quad. The tailgate was giving me issues. It had a small crack on the lower part and with a heavy load, it would bow out and pop off (when going up hills). I reinforced the bottm with a 90 degree 1/8th piece of steel. I did something similar for the top of the tailgate, but with 1/8th flat stock. I basically tacked the metal in place; making the tacks ever few inches. Even after grinding....it ain't pretty. By running the welder on a lower setting, I was able to get a decen small beat without buring through. How would you guys go about welding the metal? Running some longer beads? Attached Images
Reply:set the machine up to weld the thicker metal. focus the arc on the thickermetal and just let the puddle flow over to the thinner metal..grind off what you have ,  it is as you say set lower and is cold which means it did not penetrate deeply..post fotos of the actual work..
Reply:Originally Posted by weldbead..post fotos of the actual work..
Reply:An idea what machine you are using would help. Doing this with a mig would be easy, doing this with a FC only machine or stick will require a bit more skill. Usually you set the machine for the thinner material, but the suggestion to concentrate the bead on the thicker material and wash the bead onto the thinner one is a good technique for this sort of project..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:If you feel the quality of your welds are poor, why not just bolt the 1/8" angle to the trailer?Or....Practice welding on a bunch of scraps until you feel your welds are structurally sound (and more visually appealing).
Reply:Sorry about that. It's the infamous HF 90 amp flux. I just installed some Lincoln .035 FC wire and a .035 tip. That helped the welds look a bit better. I had the welder set to "min"...and ran my wire speed around 3ish. I had tried "max" and 7...but that burned holes in short order. I suppose I could have just bolted it...but then I couldn't have played with the welder.
Reply:Exactly what weldbead said. I happened to do this task today, attatching some 16ga to some 4 inch channel. I set the machine to slightly below the thicker metals setting and ran the arc on the thicker metal and "just along" the 16ga. I use a small weave that "threatens to touch" the thinner metal but doesn't actually touch it. Just watch the puddle "wash" into the thinner metal. Cappy cell phone pics of both sides of the weld attached. Attached Images
Reply:Thanks guys. The pics really help. Now I see how it's done; and the description makes sense. The length of metal I used was about 28" long. Whats the best number of beads to lay?  I'm thinking welding the entire 28" would be a bit of an overkill.
Reply:I think you should switch to .030 fc as that is what is recommended for 110v machines.
Reply:Originally Posted by Skier76The length of metal I used was about 28" long. Whats the best number of beads to lay?  I'm thinking welding the entire 28" would be a bit of an overkill.
Reply:Jason,Thanks, that spacing advice is helpful. In hindsight, I should have asked first...instead of welding first and asking later. Althought, this is just yard trailer, so aside from looking bad, it's not going to harm anyone/anything...aside from maybe my pride a little.Ok...here are some pics. This is how it came out after I did some grinding, priming and painting. It's still not pretty. It's a bit embarassing...but I gotta learn somehow. Bottom:Top:So there you have it. What it would look like if a bird landed on the trailer...and pooped out molton hot metal. Here's what needs to get fixed next. The body of the trailer that mounts to the area above the axle. Again, a thin metal to thicker metal job:
Reply:When welding thin to thick, concentrate the heat on the thicker metal, while letting the puddle flow into the thinner metal.11ga diamond plate welded to 3/16 channe, or angle iron (I forget which)l. 1/8 7018AC, 135amps.  (high amps in order to get adequate heat on the thicker metal, while the puddle just flowed into the sheet metal)Job certified, Pup approved Attached Images"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by farmersamm.... Pup approved
Reply:Great pics! That's exactly how I wished it had turned out. So keep the amps up...and let the puddle flow to the thinner material.
Reply:Yah, and get a new machine.It seems like Harbor Freight is still swindling people.Measure twice, cut once.Millermatic 211Millermatic 251Miller Dynasty 200DXESAB O/A Set-up
Reply:I did some more trailer work yesterday; more on "why" in a minute. Starting on the thicker metal and pulling the bead down really helped. I was able to do that in a few spots. It's still not that pretty, but it'll hold. I find that a little work with the grinder can make a "crappy" looking weld "OK" after a little time. Remember how I said the body was coming off the axle housing? After cutting a whole bunch of trees this weekend with a neighbor's relative, the trailer got tired of hauling wood. I'm going to use some bolts to put it all back together...with a few welds thrown in for good measure. There's no way I have the skills to fix this. Well, if I wasn't going to put anything in the trailer...I could fix it.
Reply:Got some practice in last night. It's much easier to get thicker to thin when the pieces are touching. When there's a gap, it gets tougher.
Reply:From your picture you said thicker metal to thin, but it looks like you have lap joint.On a lap joint, the piece that is overlapped will be able to take slightly more heat.  The piece that you are welding on edge will be able to take less heat (about 1/2 as much) than if you were welding in the middle of that plate/piece.What I'm saying is you might be fine turning the heat up to what the top, heavy piece wants and I suspect you will have no problems on the bottom, thinner piece.I would approach it this way.First, practice on a piece to get the settings right.  Quite frankly you might have that HF machine maxed out and still not burn through.  Those machines have a funny relationship between wire speed and voltage.  Set the voltage for as hot as you can handle and tweak with wire speed.For technique, I would also start on the heavier piece, making sure the gun angle is slight favoring the heavy piece and use little swirls - very small - just to get the metal to wet out into each of the pieces.  If I felt things were getting too hot, I would either pick up speed a bit or maybe increase the diameter of the swirls (again slightly).To do this you must be able to see the puddle and see the wire touch the puddle.  Sure there are people who seem to be able to weld by sense of smell alone, but you and I aren't one of them.  We need to see what is happening.  Adjustable auto-dark hood helps.  At my age, about 16" from the puddle  maximum.  I'm not sure how much spatter you get from the flux core stuff but I suspect you could get away with 8-12" on that machine.I would aim for 2" stiches.  2" inches is enough to establish a rythm and even if your starts don't look good, you have  1 3/4" to make it up. (that's my theory anyway As for the looks of your old weld.In the first picture I would say they look a tad cold (not wetting out at the toes) at least on base metal.  Could be your nervousness though.In the other pictures it looks like you never established a rythm at all.  Very cold (at least on base metal).  If your are going to hold things together with tacks, you want to use a lot more heat.  On that 90 Amp (ish) machine, highest voltage setting and as much wire as it will take.Normally, 90 Amps is not enough for 1/8" steel, but since you are welding on edge you can get away with it.One thing I would recommend is that you check the wire speed.  The wire must feed absolutely smoothly.  Any hiccups and it will mess up the looks of the weld. That means the alignment of everything must be dead on and your drive roller tension must be just right - and you need acceptable (not too much, not too little) tension on the spool.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Great advice! Thanks for typing that up. I think you're on to something with the wire speed. When I changed out the spool, I noticed the feed rate was a bit different. It would skip a bit.  At first, I thought it was dirty metal that I didn't prep correctly. But after time, it seemed that it was the feed. I should really look into that. Maybe it's time to switch back to .030.