stich welding

[Makohon]

ok so theres a few deffinitions of this, im not talking about a ricer stiching the unibody nor am i talking about doing 1 inch then skipping a inch... im talking about a hot hot delayed ''as in a long tack"  after another for tubing and basically anything else? story is, i got a fab job and my boss has been building buggys "sand/baja 1000 type stuff" and he took two well known fab schools in so-cal and was tought to stich weld... his defense was he used to weld "normal" and when he would have a hard roll/crash the weld/metal would crack due to to much heat... mainly cromo... he was tought this like i said from two well known schools and i need to adapt to his doings for my job but i dont agree... i dont want garage builders to respond to this and want pro welders/fab people to comment on this please...

[94MtnYote]

 stitch welding has a much greater chance of slag inclusions and porosity which can lead to weld failure. This proved to be true when we did our cert bend tests...

[superyota]

stitch welding has a much greater chance of slag inclusions and porosity which can lead to weld failure. This proved to be true when we did our cert bend tests...

x2.  there is a reason why your required to be able to run a 12in. pass without stopping(even with a mig cert.).  stitch welding creates a high risk of prosity due to contamination from slag, just as posted by mtnyote.  if your weld is cracking, its because  your burning too hot, or because you have porosity.  there is right amount of heat for good penetration, but also to where your not too hot to cause heat stress(tempering) of the metal to make it brittle and prone to cacking.

[TacoRunner]

First off, if your bosses cages cracked, it may have been from to much heat in the weld. Second, using Chromoly with out heat treating it is pointless and has no additional strength properties over quality DOM. Stitch welding is for people that dont know what they are doing. The only time you stitch is for sheetmetal. Thats what I was taught. Try TIG welding DOM or Chromo next time.

[Makohon]

Ya this is what I thought to.... just bugs me a fab school thought him this and now I have to adapt to his way of doing stuff that I don't agree on and have no say

[yota4x4sc]

Actually buddy who is a pro welder, tig welder says he will stitch weld stuff to make it stronger by cranking up the heat a lil bit and just stitching it together..puddle by puddle.. i am just saying what he told me a while ago, i weld both ways sometimes just depending on wat im doing 

[superyota]

All I know is, if you stitch weld on a structural cert test, its an automatic fail, and there is a reason for it. I know you might be able to make something look nice by stitch welding, with what might look like a nice bead(puddle on top of puddle), but its not going to penetrate.  And if  you crank the heat up to where it does, you're still going to have the issue with porosity. I think what ever fab school your boss went to is probably more after looks than strength.  just my   .  People like your boss bug me.  I know exactly what your talking about too.  I use to work in a shop where it was there way or no way.  As long as my name wasn't attached to the work, I didn't care.  Thats how they wanted it and thats how they got it. 

[Burl]

Ok son of a professional welder here so have some experience with this.  Depending on how long your weld surface is if you run a full length bead you will end up distorting or pulling your material out of alignment or out of square or whatever term you want to use.  Stitch welding like others have posted reduces the heat transfer involved, as for contamination don't be lazy just flap disc or wire wheel you next weld surface to remove any residual residues.  Prime example of distorting with a full length bead was when some jackass students of my dads ran a full length bead on the tounge and coupler on a trailer and if you placed the material on a flat surface the front was about 4 inches higher than the back from distortion, this is where stitch welding would have been appropriate then after it was cooled and re cleaned the rest of the welds could have been filled in.  It all depends on the type of job you are doing whether it's appropriate of not.

[yota4x4sc]

Ok son of a professional welder here so have some experience with this.  Depending on how long your weld surface is if you run a full length bead you will end up distorting or pulling your material out of alignment or out of square or whatever term you want to use.  Stitch welding like others have posted reduces the heat transfer involved, as for contamination don't be lazy just flap disc or wire wheel you next weld surface to remove any residual residues.  Prime example of distorting with a full length bead was when some jackass students of my dads ran a full length bead on the tounge and coupler on a trailer and if you placed the material on a flat surface the front was about 4 inches higher than the back from distortion, this is where stitch welding would have been appropriate then after it was cooled and re cleaned the rest of the welds could have been filled in.  It all depends on the type of job you are doing whether it's appropriate of not.

exactly