Metal heat warp

[Miles]

Man, I can't believe how much metal moves around and changes shape with just a little welding. I've read enough to know to tack the pieces together and stitch weld for short lengths to try to reduce warpage but it seems no mater what, the pieces are going to move. When welding my FB grate I clamped the pieces to the table, after they cooled I took off the clamps and the angle went sproing. Today I got to the point of welding the one inch angle, that will hold the food grate, into the CC. I cut and fit the left and right slides and positioned them in the tank. I put a small tack weld on one end of the slide and when it started to cool it pulled the other end 3/8" away from where it had been sitting. I hammered it into position and tacked the other end. I don't know how I could have clamped the pieces. I also noticed the door opening is now warped about 2-3" away from where I welded the slides.
No real question here just wondering how you guys plan for and eliminate warpage.

[Rodcrafter]

On doors it is best to weld the ends on before cutting if you can. But remember it is steel, you can bend it back if need be. It can be shaped in any way you have the resources to do. Sorta like putty, but tougher.

[Miles]

Yea a lot tougher.
I was thinking of heating the tank and hammering it straight again but afraid I'll make it worse.