DIYbanter - View Single Post - How to straighten a 5x10ft, 3/4" steel plate

Ignoramus8008

On 2013-10-20, wrote:
On Sat, 19 Oct 2013 18:44:23 -0500, Ignoramus23452
wrote:

I have a 3/4" thick steel plate that is 3/4" thick. It is bowed in the
middle along its length. The worst un-straightness is in the middle
and it is appx. 1/4". I would like to straighten it. How can I
realistically do it, if at all.

i
If using shims and weight possible you can do that. But you can also
just use heat and water. Heating along the bulged side and then
cooling will shrink the metal, eventually pulling it flat. You could
use a big oxy-acetylene torch or a weed burner torch. I would use a
weed burner, actually a few of them, to heat the full length of the
bend all at once. Probably easiest though for you would be to use
wieght and shims. The plate would need to be shimmed a certain
distance above the floor and then the weight applied. By increasing
the shim height you will be able to increase the amount of deflection.
The plate will need to be deflected quite a bit before it starts to
take a permanent set in the direction opposite to the set it has now.
But as soon as this happens it will require much less added deflection
to get even more set. So shim up one edge, add the weight, remove the
weight, check to see if plate is starting to flatten, add more shim,
and repeat. If you do bend it too far you can turn it over and repeat
the process. But if you do this be aware that it will require much
less deflection for a certain amount of set than it did when working
on the other side. I personally would try the heat and cool method
first if I had the torches because there will be less likelyhood of
the plate warping again over time. But the bending method will work. I
know because I have straightened many shafts and plates.
Eric

Eric, thanks. I have a big "Belchfire" fuel/air torch. I may give it a
try.

i