Taking a bow out of 1” thick plate

[Rob65]

Originally Posted by JohnBoy

Could welding do anything?

buy a box of cheap rods and burn them in a circle on the underside.

I mean if you wanted you could even view it as a learning oppurtunity to practice your overhead stick technique.

Yes, this. It’s amazing how much a weld on a plate will distort it.

I think you would be surprised by what can be done using this method. I’ve seen some heavy beams accidentally bend by some fool welding brackets to them inappropriately.


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[arizonian]

Originally Posted by threepiece

I suspect you may be misunderstanding my intention here. The 1/2” x 3” bar will be in tension when used as a truss, not bending. As I’m sure you know, the tensile load capacity of steel is far greater than bending load capacity. I would not be surprised if a 1/2” x 2” bar will do the job.

I think you're onto something. Build a truss or two into the table on the underside, use some kind of jacking mechanism, and leave it(them) in place for life.

[threepiece]

Originally Posted by arizonian

I think you're onto something. Build a truss or two into the table on the underside, use some kind of jacking mechanism, and leave it(them) in place for life.

Yes, a variation on this theme would be to build a rigid structure for the underside that would be more suitable for the desired table. Fastening screws could then be used to both draw the plate flat and fasten it down.

[metalmagpie]

The legs of the Space Needle in Seattle are enormous I-beams. They are curved in two dimensions. Those bends were done by savvy old guys with oxyacetylene torches at Paccar in Bellevue, with frequent testing against plywood templates. Flame straightening is possible but you had better know what the f you are doing or you can screw your part up worse.

I'll tell you right now - flame straightening with a rosebud is a terrible idea. You want skinny lines perpendicular to the bend axis, on the convex side of the bend. You need a lot of heat, you have to use acetylene because propane or its derivatives are not really hot enough.

There are not many reference books on flame bending/straightening. "Flame Straightening Technology for Welders" and "20 Flame Straightening
Processes" both by John P. Stewart are very good. They have recently been reprinted in paperback and are obtainable for under $100. But I was able to read them both via interlibrary loan, which is free.

metalmagpie