Allo! Je suis votre moment Eau Chitte!

Putting the final welds on a 28 X 26 12 ga. SS plate, nicely curved to a consistent radius, and which cost no few pennies. Everything was going
well. I had 25 small 1/2" X 1/2" posts holding the plate to its mild steel frame. The 309L joined the metals with ease and panache and the whole thing was looking pretty nice.
And then the Eau Chitte moment arrived. John, the Dipstick, (that would be Your Respectful Author) welded the center supports first, then got truly stupid and welded the outer supports next, neglecting the intermediate ones, then went back and tried to weld those intermediate posts.
And I said to myself, too darned late: Now, Self, what the Liver-Loving Hell did you think was going to happen when you make a weld equidistant between two completed ones on the same curved line? Yep, they pulled and made three of the prettiest bubble bumps you ever saw. That 12 ga. SS pulled down around the posts quite prettily, if you like expensive vertical fornications.:)
Never occurred to me until too late that welding the center and ends introduced stress into the plate, which promptly relieved itself when the plate around the intermediate posts got to welding heat.
Might, _might_, have got away with it with TIG, but OA wasn't so forgiving. Too large a HAZ, apparently. Too dumb a welder, certainly.
What started out to be a form for heat bending HDPE for custom wheelchair seating backs is now a rather nice looking, but useless objet d' junque.
Damn! :)
Oh, well, off to buy another bent plate and start over. That $2000 entry fee for getting into TIG welding is looking cheaper and cheaper.
(Although that might have made little difference, considering the screwup by the Party of the First Part.:)
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John Husvar wrote:

I was taught that stainless has much more distortion issues than regular steel. I don't know what the solution to your problem would have been, maybe some kind of preloading before welding.
I hate those eau chitte moments.
GWE
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