I would like to start a new thread on flame quenching, heat shrinking, heat bending, heat straightening or whatever you refer to it as. What I am talking about is the process of either bending or straightening steel by applying heat and then quenching with water to either straighten a bent piece of steel or to bend a straight(er) piece of steel. I did some searches on this and was dismayed to find a thread started by a member to straighten a slightly curved piece of 2x4x1/2" plate for a table top. At the end of many attempts suggested by replies posted he solved the problem by returning the plate to the supplier to exchange it for a flat one. While exchanging the plate for a flat one is a good solution, he did not find simple advice to straighten the plate.
What I am talking about is the use of heat and cooling (water) to bend or straighten steel without using mechanical force to do so. Simply put heat is applied to the steel to heat it red hot causing it to expand. Then water is sprayed on the hot spot to lock the steel in it's expanded position. I'll give an example.
Imagine a 2x2x12 inch square bar, which is not restrained in any way. Simply put, if you apply a large amount of heat, to the top surface at the mid point to heat it red hot and the red heat penetrates past the middle of the bar towards the bottom, the top will expand and the cooler bottom will restrain it causing the bar to bend in an upwards direction. Now if the bar is allowed to cool slowly the red hot top will shrink as it cools and return almost to it's original shape. If instead we quench/cool the red hot top surface with water while it is red hot the bend will be restrained top and bottom and cool in the as bent position. This can be repeated along the steel bar until the bar is curved to the desired shape. This is very poweful and can bend the thickest steel if enough heat is available. I have done this myself, using a rosebud on trailers that were bent. I have seen lo-boy heavy equipment floats re-arched from a sag to a like new arch. I have also seen standard I beams curved into arches using this technique. It can be used to either bend or straighten steel, no mechanical force required.
I would like to see others post to this thread with their successful experience doing this, and for others to post questions. I know it was one of those moments where I knew I had learned something truly amazing the first time I succeeded in doing it myself. It is not a "black art" and every welder needs to know about this.
What I am talking about is the use of heat and cooling (water) to bend or straighten steel without using mechanical force to do so. Simply put heat is applied to the steel to heat it red hot causing it to expand. Then water is sprayed on the hot spot to lock the steel in it's expanded position. I'll give an example.
Imagine a 2x2x12 inch square bar, which is not restrained in any way. Simply put, if you apply a large amount of heat, to the top surface at the mid point to heat it red hot and the red heat penetrates past the middle of the bar towards the bottom, the top will expand and the cooler bottom will restrain it causing the bar to bend in an upwards direction. Now if the bar is allowed to cool slowly the red hot top will shrink as it cools and return almost to it's original shape. If instead we quench/cool the red hot top surface with water while it is red hot the bend will be restrained top and bottom and cool in the as bent position. This can be repeated along the steel bar until the bar is curved to the desired shape. This is very poweful and can bend the thickest steel if enough heat is available. I have done this myself, using a rosebud on trailers that were bent. I have seen lo-boy heavy equipment floats re-arched from a sag to a like new arch. I have also seen standard I beams curved into arches using this technique. It can be used to either bend or straighten steel, no mechanical force required.
I would like to see others post to this thread with their successful experience doing this, and for others to post questions. I know it was one of those moments where I knew I had learned something truly amazing the first time I succeeded in doing it myself. It is not a "black art" and every welder needs to know about this.
