A little advice if you would. I don't know much about steel and built a
wood fired maple sap evaporator with fire brick lined block sides and rear.
The top and front are 1/4" plate. The outside dimensions are 56"L x 48"W.
It served my purpose but I was surprised at how much it warped as it got
hot. I have a 23"x37" hole in the top that the evaporator pan sits over and
the flame contacts the bottom of the pan. In the 48" width at first it
probably warped 2" vertically and had a diagonal warp of about 6". I bolted
1-1/2" x 1/8" angle on both sides and the rear and one piece of angle across
the width of the opening in front of the 6" flue pipe opening. It calmed
the warping down some but I am surprised at the strength of the warp, it
even bends the angle iron. The front has a barrel stove door and doesn't
warp.
What weight plate steel would I have to use to keep it from warping? Can a
person have a piece of cast iron made? Would it be affordable? Any other
ideas would be appreciated.