Warping BAD

[RAS]

I am trying to weld three 1x3 11ga. square tubes notched across a 2x2 11ga. square tube. This would resemble a fish skeleton, where 1x3 notches are cut across the 2x2 tubing then the 1x3 tubes are inserted into the notches and welded. They are 15.5" apart on center with the first one at the very end of the 2x2 tube. It's warping very badly. The shop claims clamping won't help. ANY SUGGESTIONS ANYONE?

[MMW]

Clamping always helps but it might not help enough. You can try to clamp them so they are bent in the opposite direction before welding. When unclamped they can return to being flat. You can also try back heating which after welding you heat opposite the weld to get it to warp back to flat. You can try cold bending them after they cool. You can try to clamp them back to back if the parts are the same. All of the above work but without pics it is hard to say which is best. In simple terms when you heat metal it expands & then contracts as it cools. The problem is it contracts more than the original state it was in which is why it warps.

[MMW]

It sounds like the shop you are dealing with does not have a lot of experience with tubing frames etc. This is a common thing & knowing how to keep it flat or return it to flat comes from experience. Sometimes the set up or straightening takes longer than the actual welding.

[Jack Olsen]

How many are you making? It's hard for me to picture what you're doing from the description. But if it's like a fish spine, then cold bending might be the way to take it back to straight. I made a fence where all the picket welds were on one side of the lateral pieces and each piece got a curve to it as a result. When I was finished welfing, I set each section up on my table so it was hanging off, clamped it loosely and bent it slightly. Then I moved it a couple of feet further and bent it again. This was for 8' sections. It was pretty easy to get it straight (I say that because it was my first welding project).

[RAS]

Thanks Jack,

I think I have pretty much the same issue. I only have 3 cross pieces and only one tube down the middle. Now imagine if there were notches cut in your runners so the vertical pieces of your fence countersunk down in the runners. That's my issue. To make matters worse my process requires nearly twice as much welding at each joint, thus twice as much heat.

[Sonora Iron]

Pictures would be a big help.

If I understand you correctly, once you have all your notches cut, and before you tack in the tube, start in the center of the spine tubes and heat a cherry red circle on the backside of the notch, work your way out from center. Once you place the tubes inside the notches, ONLY weld the parts that are touching, if the gap doesn’t close up after the welds cool use a pony clamp or come-a-long to pull the gaps in tighter.

I’m only guessing on what you’re trying to do, pictures would be a big help!

[MMW]

If your notches are oversize it will make the problem worse. You need a tight fit to minimize warping. From what your describing it doesn't sound like a big deal to keep it or get it straight. Do you have a table to clamp it to?

[vin-man welding]

sounds to me that you need to turn down the welding heat and jump around more. don't try to weld the joint all at once. put a tac on the open gap side first. then start welding one side at a time and let it col before welding the same joint again. i know i didin't do a good job of typing what i mean hope you get it.

[RAS]

Pictures / drawings

Here you go guys. I don't have any photos of the actual parts but here is the drawing from which they are made.

[Jack Olsen]

Are you just making one -- or several? If it's just the one, I would cold bend it. If you're making 50, you could sequence the welds to minimize the bending, pre-bend it in the opposite direction, or clamp it down pre-bent.

[Sberry]

Yes, tight fit, good tack up and proper sequence along with minimal sized welds would go a long way towards reducing warpage.

[Sonora Iron]

My plan of attack would be to use .023 or .030 Mig, make one, (and only one!) downhill weld in each location then move to the furthest location possible, and only make one downhill weld. Move again, and NOT be in any hurry! Then once completed and it cooled down, I’d go get a shop rag, bucket of water, and wheel the O/A set over and straighten the darn thing out.

[Sberry]

I would tack it at every corner prior to welding.