another ? on civic shaving

i used 14 and 18 gauge or my car

the doors are 22g. use the same gauge as the door. you cant avoid warping, not matter what you do. the problem with thicker metal, is that when it gets warm in the sun, or gets cold at night or in the winter, it will expand and contract differently than the stock metal around it,,,which will cause problems down the road. just use the same guage and butt weld everything. doesnt matter how big of an area it is.