I did not all replies here
Just do a little weld on side and watch it wiggle back and forth and keep straight on last pass.
It a lot easier to show on job.
Dave
Originally Posted by husq2100
Hey all,
I was welding an outside corner today. Some 3/8" to 1/2 flat bar, only about 3" long each. Im fabricating a bracket for a disc brake caliper. I had it all in place, tacked up on the inside, then removed and welded the outside corner. The two plates only overlap by maybe 1/16" so lots of "corner" I also do one fillet pass on the inside to add a bit more strength. But that gets done last.
Anyway, before doing the root run, I had set 2 bevels (one as a back up incase I bump the main one) to record the angle it was tacked at. What I found is that after each pass on the outside corner, the two pieces were pulling towards each other (to the internal corner)
Why? I would have thought they pull apart, towards the weld...
Use the one you have( expendable one) to make a fixture. It might magically be off the perfect amount in the correct direction to self correct on cooling.
It was previously suggested that perhaps excess penetration heated the tacks and caused it to pull in what you would normally think is the wrong direction. The distortion caused by the heat doesn't lie. Don't know why you're so hung up on this and getting in a tizzy with people trying to help you. There had to be more concentrated heat on the tacked side to cause it to pull that way. Tacking the gusset in at the outset with everything fully welded afterwards isn't going to effect strength enough to make any difference. Gussets are tacked in place on initial assembly all the time.
It was previously suggested that perhaps excess penetration heated the tacks and caused it to pull in what you would normally think is the wrong direction. The distortion caused by the heat doesn't lie. Don't know why you're so hung up on this and getting in a tizzy with people trying to help you. There had to be more concentrated heat on the tacked side to cause it to pull that way. Tacking the gusset in at the outset with everything fully welded afterwards isn't going to effect strength enough to make any difference. Gussets are tacked in place on initial assembly all the time.
Dave, we’ve already been through this, and I don’t have to explain myself again.
I’m appreciative of those that read and helped with good info.
It was previously suggested that perhaps excess penetration heated the tacks and caused it to pull in what you would normally think is the wrong direction. The distortion caused by the heat doesn't lie. Don't know why you're so hung up on this and getting in a tizzy with people trying to help you. There had to be more concentrated heat on the tacked side to cause it to pull that way. Tacking the gusset in at the outset with everything fully welded afterwards isn't going to effect strength enough to make any difference. Gussets are tacked in place on initial assembly all the time.
I'm with Dave. I would find a way to (temporarily) tack the gusset in place, then weld the bracket most of the way out, then remove the gusset if need be to finish welding (by that point, the thing shouldn't be moving much more), then add the gusset back in. Good luck.
ETA: And for what it's worth, I have found that clamping things up when you weld doesn't necessarily eliminate welding distortion (at least up to the yield point of the steel) ... what happens is, the weldment just gets "sprung" in the clamps, and then when you release the clamps -- Viola! There's your distortion. It might not distort as much as if you hadn't clamped, but it will almost always still distort, in my limited experience.
I'll give you one more worthless opinion. I suspect you may have trouble anticipating the pull in this one since it did not pull like you would have expected and the other one didn't pull the same either, but you may get lucky again. Would it be possible/advisable to redesign the weldment by extending the vertical plate to the bottom of the horizontal plate? Since you lack machining capacity, grind the mating surface of the horizontal plate to the correct angle and bevel the edges. and tack then weld across the bottom and in the elbow. If the heel is too wide, grind it off post weld. Just another opinion worth what you paid for it.
It some I learned welding base plates on column.
It something that easy to show in shop as the base plate wiggle around and how fix it.
I have been shops where the welders would weld all one side and part would warp.
The way best is practice
Dave
Originally Posted by Kelvin
I'm with Dave. I would find a way to (temporarily) tack the gusset in place, then weld the bracket most of the way out, then remove the gusset if need be to finish welding (by that point, the thing shouldn't be moving much more), then add the gusset back in. Good luck.
ETA: And for what it's worth, I have found that clamping things up when you weld doesn't necessarily eliminate welding distortion (at least up to the yield point of the steel) ... what happens is, the weldment just gets "sprung" in the clamps, and then when you release the clamps -- Viola! There's your distortion. It might not distort as much as if you hadn't clamped, but it will almost always still distort, in my limited experience.
Seems the consensus was the tacks being re heated and pulling ( which explains the left movement on root, but not on subsequent runs with more filler and weave....)
So my solution was less tacks, only 2 in fact, right on the very ends. Then the root was put in colder. Angle remained unchanged. 2nd pass had it pull to the right a little ( no weld on the left at this stage) . Fillet on left side returned it. Then added the small gusset mid section. Tacked in place. Finished out the outside corner with 2 more passes. Angle correct.
(Btw photos from my phone seem to get rotated when attached?)
Seems the consensus was the tacks being re heated and pulling ( which explains the left movement on root, but not on subsequent runs with more filler and weave....)
So my solution was less tacks, only 2 in fact, right on the very ends. Then the root was put in colder. Angle remained unchanged. 2nd pass had it pull to the right a little ( no weld on the left at this stage) . Fillet on left side returned it. Then added the small gusset mid section. Tacked in place. Finished out the outside corner with 2 more passes. Angle correct.
(Btw photos from my phone seem to get rotated when attached?)
Just take a hammer to it... Seriously dude? Some point like the end product to look nice not beat all to hell like a iron worker got a hold of it. You kill me.