Is it ever ok to stich weld, mig

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Is it ever ok to stich weld something. Basically pulling the trigger, moving forward, pullling the trigger again. I watched a guy do it uphill on a trailer member, and also a welder at a town garage mention it. Is there scenarios that make ok, and other scenarios that make it a hell no!?
Reply:Any weld with an interruption, (short weld length, gap, short weld length) is a "stitch" weld from my experience. I use them a lot on thinner things and then go back and fill the gaps to keep heat from warping.Not everything needs a continuous weld length to hold it together and I see this a lot is structural items also.SlobPurveyor of intimate unparalleled knowledge of nothing about everything.Oh yeah, also an unabashed internet "Troll" too.....
Reply:I've seen it done as a "fix" for someone who simply can't weld. It's a poor way to do things if you need structural strength. Mig often has cold starts, and a lot of stop starts just leaves a lot of potential weak points.Now that's a bit different if we are talking about body work on sheet metal. There that "tack, tack, tack..." is a very common way to get good fusion and keep heat levels down to prevent distortion. In this application it's certainly an acceptable practice..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:I've stitch welded a lot of .065" wall sq tube I've recycled from ATV crates and built a lot of different things w/ it and haven't had a weld fail/ crack yet.                               MikeOl' Stonebreaker  "Experience is the name everyone gives to their mistakes"Hobart G-213 portableMiller 175 migMiller thunderbolt ac/dc stick Victor O/A setupMakita chop saw
Reply:a stitch weld is simply a weld pattern with interruption along a member, i.e. 2-6 stitch would be 2" long weld beads spaced evenly on 6" centers ...What i think you are referring to is simply stacking tack welds.  Hold the trigger for a quarter second, then release.  move forward 1/16-1/8" and repeat where you get a stack-of-dime look.for anything structural ... it is not recommended by most.  a lot of automotive welders like it for its easy of use and aesthetics but most other welders see it as a shortcut or crutch for those that cant weld.I sure as hell wouldnt trust my life to it ... i might trust it enough to let my ex-wife test it though.  AWS CWI xxxx21711968 SA200  Originally Posted by WelderMike  I hate being bipolar, It's awesome.
Reply:I thought the thread said "stick" welding, (I wasn't wearing my reading glasses.)After I had a cow, I put my glasses on.Thin material and large gaps will challenge you to dab. Better fit up, faster progression, and lower heat input will all help.City of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:Both of my semi trailers have 3/4" thick tension strips stitch welded to the lower I beam flanges which is common and why they rust and spread so badly there. Both are factory built trailers. One is the trailer I was learning to air arc the welds from and it worked well after grinding the paint/rust to conductive metal.SlobPurveyor of intimate unparalleled knowledge of nothing about everything.Oh yeah, also an unabashed internet "Troll" too.....
Reply:People use this terminology differently, the correct meaning i think is what AFFENDE said, making for example 2" welds every 6" or so.As was mentioned, overlapping tacks is what you are talking about and is done on really thin sheet metal to minimize distortion. I use it on 20 gauge auto sheet metal. I always gap everything 0.040" for full penetration so any straight bead longer than 1/4"-1/2" or so will blow holes through the metal. Overlapping tacks work fine for this as long as they penetrate completely where each tack meets the next.
Reply:In the structural welding world, you’ll see intermittent welds called for quite often. In my line of work it seemed as the engineers really liked 6 on 12 for some reason. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Brendonv, both people who you mentioned at the start, the guy welding on the trailer and the guy at the garage, were using this technique to repair trailers etc.  When making those kind of repairs you sometimes need to set the proper techniques aside and just an adequate/functional repair made.  Functionality and serviceability are second only to getting paid for the repairs you make
Reply:CEP I think he is talking more on the lines of just globbing a weld down with the trigger and releasing then moving up a bit and doing it again. Those are intermittent fillet welds your explaining to him. I see welders do it here in this shop ALOT! I even do it sometimes if it is nothing serious. Mainly tacking something together or filling in areas. BUT if it deals with structural components that take on a dynamic or static load HECK NO! I am not going to get into a rant on the welders in this shop I see doing it. And they swear up and down it holds just as good as a full pen weld. I almost want to shave my head and start bashing cars in with a woofle ball bat when they say that. Some people just wont understand they factors that go into play because they are know it alls and don't want to see the big picture of a weldment.
Reply:Andrew on the job I only did it when the blue prints said to. Here at home I’ve done it a few times, all depends on what I’m building. Before painting I’ll fill the gaps with caulking, so water won’t get under and rust things out. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Originally Posted by brendonvIs it ever ok to stich weld something. Basically pulling the trigger, moving forward, pullling the trigger again. I watched a guy do it uphill on a trailer member, and also a welder at a town garage mention it. Is there scenarios that make ok, and other scenarios that make it a hell no!?
Reply:hey CEP that's a good idea lol. caulk in between the stitch welds  !
Reply:Here you go. Brand new portable lift rated at 1000 pounds @ 48" lift.I call these stitch welds. Probably something else by others.Thanks,SlobPurveyor of intimate unparalleled knowledge of nothing about everything.Oh yeah, also an unabashed internet "Troll" too.....
Reply:Im sorry aout the wrong terminology. I a speaking about a series of "tacks" done intermittent mostly uphill, one after another with no lengthly pause.
Reply:yea its garbage unless your working on auto body, sheet metal , etc... OR if it isn't meant to be load bearing or have any kind of structural load on it. Don't make a habit out of it or do it as a personal practice on everything. Look I do it to clean up some of the welders welds where im at now. If the unit comes to me and the welds look gnarly I might do it on some things and utilize the "intermittent-tack weld technique" LOL! But generally to clean up some undercut alongside a weld I will run MIG downhill fast to create a flush looking bead just to cover it up. Only for cosmetic purposes. I will tell a grinder go over it and blend it all in together.
Reply:Originally Posted by AndrewDavenport89But generally to clean up some undercut alongside a weld I will run MIG downhill fast to create a flush looking bead just to cover it up. Only for cosmetic purposes. I will tell a grinder go over it and blend it all in together.
Reply:Originally Posted by AndrewDavenport89yea its garbage unless your working on auto body, sheet metal , etc... OR if it isn't meant to be load bearing or have any kind of structural load on it. Don't make a habit out of it or do it as a personal practice on everything. Look I do it to clean up some of the welders welds where im at now. If the unit comes to me and the welds look gnarly I might do it on some things and utilize the "intermittent-tack weld technique" LOL! But generally to clean up some undercut alongside a weld I will run MIG downhill fast to create a flush looking bead just to cover it up. Only for cosmetic purposes. I will tell a grinder go over it and blend it all in together.
Reply:^^ yea that's cool it has a stitch timer for auto body work. LOL the machine we used in the body shop was just an old miller. don't even remember what series. It had probably been then since they started in the 80s lol. We used that thing for EVERYTHING haha. just turn her down when working on the sheet metal tacking and turn her up when welding a frame back together.
Reply:Originally Posted by AndrewDavenport89^^ yea that's cool it has a stitch timer for auto body work. LOL the machine we used in the body shop was just an old miller. don't even remember what series. It had probably been then since they started in the 80s lol. We used that thing for EVERYTHING haha. just turn her down when working on the sheet metal tacking and turn her up when welding a frame back together.
Reply:nice, plug welding the seams right. Dril the weld out with a 1/8th bit, then take a honing drill bit and drill the weld completely out separating the two pieces from each other. Yea I did that for days at a time on truck beds and quarter panels. Even cutting cars in half. The seam under the front seats(floor pans) all the way across. Then you have to cut the drivetrain tunnel with a sawz-all. Rocker panels have to be cut the same distance back from the wheel on each side and the window framing. a lot of measuring and exact cutting when splicing two cars together.
Reply:Originally Posted by AndrewDavenport89nice, plug welding the seams right. Dril the weld out with a 1/8th bit, then take a honing drill bit and drill the weld completely out separating the two pieces from each other. Yea I did that for days at a time on truck beds and quarter panels. Even cutting cars in half. The seam under the front seats(floor pans) all the way across. Then you have to cut the drivetrain tunnel with a sawz-all. Rocker panels have to be cut the same distance back from the wheel on each side and the window framing. a lot of measuring and exact cutting when splicing two cars together.
Reply:Bear with me,I'm a rookie.  Isn't xx inches of weld with xx inches of gap between them adiquate on many structural assemblies?  Stated another way,is it sometimes acceptable to do this to facilitate disassemblly at a later date,conserve material or time?  And in a third sense,if five 2" beads with 6" gap between each bead is adiquate,is there reason to make a continous bead instead?  The "Flying Irishman" who ran our local farm repair business allways said "if a little bit of daubing do a little bit of good whole lot of daubing do whole lot of good".
Reply:Yea when cars were actually worth it haha. Yea the state puts a few too many regulations out there on wrecked salvage titles. Especially the totals. Its only because the backwoods guys who rebuilt them and did a horrible horrible job on them and they sold the vehicle.....vehicle gets in another wreck and kills the person in it because the car just split in two or the welds failed and the roof comes flying off. You definitely have to know what your doing when you attempt to rebuild a wrecked vehicle. There are no shortcuts. But the people who did use shortcuts made it worse on re-sale value now for the people who know what they are doing. @Jax - yes many structural assemblies use stitch welding do minimize warping of materials on long runs. PLUS there is no need to have a completely welded piece if there is no need to. It is a waste of filler metal. You have to look at the length, stress (dynamic or static load), wind shear, earthquake rich enviroments, hurricane force potential structures. A lot of things come into factor when deciding "Do I really need this welded completely out? or is it time to just put stitch welds to save money and time".Originally Posted by JaxBear with me,I'm a rookie.  Isn't xx inches of weld with xx inches of gap between them adiquate on many structural assemblies?  Stated another way,is it sometimes acceptable to do this to facilitate disassemblly at a later date,conserve material or time?  And in a third sense,if five 2" beads with 6" gap between each bead is adiquate,is there reason to make a continous bead instead?  The "Flying Irishman" who ran our local farm repair business allways said "if a little bit of daubing do a little bit of good whole lot of daubing do whole lot of good".