Welding Distortion - How to Prevent?

I built myself a tool stand, with the base made out of 5/16" thick steel
20 inches diameter, a 1 inch square solid bar coming out of the middle
of it, and 5 inch by 5 inch by 1/4 inch thick gussetts. The picture is
at the URL below.
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I had quite a bit more welding induced distortion that I had expected,
to the extent that the 20 inch diameter circle ended up with about 1/16"
of crown in it. That made the tool stand unsteady, so I welded some
flat bar to the bottom around the perimeter to stop it from rocking.
That solved the problem for this project, but I would like to know what
I should have done to minimize distortion. Trying to learn from my
mistakes.
I confess that I did not do much to minimize distortion on this build, I
welded up the gussets against the 20 inch disk first, and then tack
welded the 1 inch bar to the gussets, and then welded solid the 1 inch
bar to the gussets. I imagine that the final welds shrunk and pulled
the dome into the disk. I was using 1/8 inch 6010 rod, stick welding.
Should I have done several small tacks before welding it up? Should I
have welded the gussets to the disk first? Should I have somehow put a
crown in the disk before I welded it? (Not sure how feasible that would
have been, but I could have tried something).
What should I try next time I do something like this?
Richard Ferguson
My email, with obvious changes, is below
fergusonREMOVEITsculpture at ANDTHIS att . net
Reply to
Richard Ferguson
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Your configuration is going to warp, not too much you can do about it. You are putting all the heat on one side of the plate, it will pull toward the heated metal. I would have expected much more than the 1/16" you measured!
You could change things by cutting holes in the plate and welding from the back (underside). You can clamp it down with some sort of strong back (big beam underneath) You can try short 1" welds and peen them while they are hot.
Richard Fergus> I built myself a tool stand, with the base made out of 5/16" thick steel
Reply to
Roy J
One thing you do is what all inexperienced guys do. You put on *way* too much weld. 2" around the ends of those gussets would be plenty strong enough. But with flimsy stuff like 5/16" plate you'll never get it flat anyway, so you're better off to design in 3 feet. Another thing you can do is sort of a meatball thing--take a 20 pound hammer and pound the base flat. A big hammer skilfully wielded will really move 5/16" plate easily. I've flattened a whole bunch of 3/8" plate, trust me. If it really doesn't move, heat it where you want it to "hinge" and then hit it beside the heat zone. Or just heat it where there's too much steel until you get a 2" cherry red spot and then quench it with a hose, then move over a few inches and repeat. You can shrink plate real effectively this way.
I used to be terrified to weld something together at 90°. Now I just stick 'em together, weld it up, take a heat in the forge and square it up on the anvil. Perfect corners every time.
Grant
Richard Fergus> I built myself a tool stand, with the base made out of 5/16" thick steel
Reply to
Grant Erwin
Next time stagger stich the bar and gussets together first. I think something like a one inch weld every four inches would be enough. By stagger I mean that the one inch in four on the other side of the Tee joint would not match. After the stand is built then weld the plate to the gussets. I would suggest a total length of all your stiches to be maximum of eight inches. Any more and thing will warp all over the place. Of course you already know that. You are now a member of the club. Randy
Reply to
Randy Zimmerman
"Richard Ferguson" wrote
Weld it a LOT less, jump around in your welds making two welds opposite of each other, and wait about five minutes between each weld. Clamp to something flat, or a couple of pieces of channel.
Still may warp, but less. You just put way too much welding on there.
Steve
Reply to
SteveB
Start with used truck wheels. Make up small plates to bolt to the wheel pattern.
These have the advantages of being disassemble, cheap and are easy to weight down if you need to make the base stable. Just fill with rocks, or cut-off metal scrap.
Reply to
frank
Way too much weldment on the gussets. You could have downsized the gussets considerably-they don't need to be so big. A couple inches on the base section would be plenty. Also, you only need to weld the gussets at the corners and tips. Welding the entire length of the legs is pointless. JR Dweller in the cellar
Richard Fergus>
Reply to
J R North

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