One large bead or multiple?

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I was recently replacing rusted out hanger brackets on an equipment trailer came across a situation that I could lay in one big bead or run multiple beads. See pic; 3/16" steel, 1/2" radius to 3/4" base plate. The OEM had a tiny stringer bead that didn't show any failure but looked barely adequate. Over the years I've had coaching that varied from "don't screw around, turn up the heat and burn it in one pass!" to " heat= distortion and stress"; I understand the concept of distortion in a sheet for example but what about work more compact? On a related topic I will be replacing the lip assembly on a mid sized excavator this winter, I've done a few backhoe and small loader buckets without any failures but this is on a machine with some "nut". I was going to start in the center, work outward toward the lips and alternate on the inside and outside to balance the heat- what is the preferred method? I recently bought a fresh tin of 7018 for this- lip is AR so there isn't an abrasive consideration here, only bending and some impact.Thunderbolt AC/DC330AB/P + Bernard coolerSyncrowave 250Oxy/Ace torchDayton 160 MIG6CF pot with 185 compressorToo much big equipmentEven more small tools
Reply:i would 3 pass it, but that is just me.i tend to think (especially on a joint like your showing) that a hot and narrow "root" shoved as deep as you can into that joint is a great guarantee that you have both pieces together. its crucial to really shove the rod in there, and let it fill up a bit to ease slag removal. then a pass low on that one and a pass high to finish it off. when done, you should only see 2 beads.im biased though as i think a good 3 pass looks better than any single on flat or horizontal welds.vert up, its got to be pretty wide for me to want to show more than one beadLast edited by 92dlxman; 12-21-2014 at 02:27 PM.bosses stuff:trailblazer 325maxstar 200my stuff:sa 200fronius transpocket 180100 amp Lincoln w/f97 f350 DITKevin
Reply:Hard to go wrong with multiple beads as the penetration and fusion is undoubted. Less heat also means less crystallization of the steel at the molecular level meaning brittle.SlobPurveyor of intimate unparalleled knowledge of nothing about everything.Oh yeah, also an unabashed internet "Troll" too.....
Reply:Always opt for more passes or go to a bigger electrode and more power.old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:Don't start in the middle and weld to the ends. Do the opposite, start at the ends and meet in the middle. Starts aren't as prone to issues as your stops and the craters.
Reply:I vote multiple passes.  Most codes require that fillets be 3/8 or less on a single pass.  Large fillets tend to crack from shrinkage stress across the face.  Also preheat....preheat ... preheat.  Preheating slows the rate that your welds cool which is the important part. Also preheat will reduce distortion,.
Reply:As a rule I would rather single but multi sounds good here to me.
Reply:Borderline though.
Reply:When in doubt, run multiple passes.....The answer to this thread is obvious.Just a couple welders, big hammers, grinders, and torches.Work will free you.Men in dirty jeans built this country, while men in clean suits have destroyed it. Trump/Carson 2016-2024
Reply:Don't start in the middle and weld to the ends. Do the opposite, start at the ends and meet in the middle. Starts aren't as prone to issues as your stops and the craters.
Reply:Stringers for me. One big *** pass might be a little quicker but for me better control is using stringers.
Reply:This one is pretty much a slam dunk.Sometime back, I replaced the suspension on a float.  All new hangers, springs, perches, etc.You only need one pass.In my case, the radius was pretty big, the concavity pretty deep, and took quite a bit of filler to do it in one pass.  Go slow, and make sure you've filled the concave area, or you'll have major "fallout" (unfilled voids).  I'm running 1/8 7018 at about 125amps with a preheat on this one.  Hutch, and Reyco, will recommend 1 pass in their WP's.  Basically ram that stick in there, wait for it to fill, then move on.  These are sort of difficult welds to do with stick, they can fool you.If you don't feel comfortable doing it in one pass, fill the deepest part of the notch with 3/32, then move up to 1/8 for the final fill.  Your hanger in the pic you posted doesn't look like it's too deep though."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Every time you add a pass, you're adding shrinkage at the weld joint, which will lead to some distortion.  The purpose of a preheat on a joint like this is #1 get some heat into the heavier plate for good penetration, #2 preheat makes for slower cooling, thus helping to relieve stresses in the weld"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Your preheat also serves to prevent weld cracking because it cools slower"Any day above ground is a good day"http://www.farmersamm.com/
Reply:With the thicker plate (trailer beam/frame), you're looking at a relatively large thermal mass.  Hard to bring up to proper heat with just a weld pass.  And because it's bigger than the hanger mass, it cools in a different manner.  Dissimilar rates of cooling.  The idea is to bring both parts up to a good temp so that internal stresses have a chance to play out."Any day above ground is a good day"http://www.farmersamm.com/
Reply:This is a classic case of a restricted joint"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by farmersammThis is a classic case of a restricted joint
Reply:Originally Posted by jef1Welding from the center out will definately be the better choice.  When welding from the outside in you trap and compound the stresses adding to the possibility for cracking and distortion.  If stress can escape it will don't lock it into a prison.  Try welding heel plates on a loader bucket from the outside in and you are sure to hear the big pop.  IN MY EXPERIENCE
Reply:Thought this might be handy for reference.  Note that, unless specified my trlr manufacturer, the welds must be held to within 1/2" of the free edge of the flange."Any day above ground is a good day"http://www.farmersamm.com/