I usually have been building frames with most of my projects. I don't do a lot with just flat plate and this is where my mistakes came in. I don't have a welding table and forgot I needed to tack it down to help keep it from warping.
Let me know what you think. Maybe weld strips on the other side to warp it back and then grind them down? Heat the back on each side of the hitch bar with a torch and bend with a sledge hammer to get a flatter mounting surface? Heat the other side then cool with water then once flat heat again and let it cool slowly?
Here is a picture looking from the backside and upside down, to see the curve the most. The hitch bar is on top and faces away from you. Also, I can't figure out how to get Google Photos to show up other than just as a link, but it auto uploads from my phone so here goes.
More detail if you are interested or have questions:
I was following Warn's style of the hitch mount even though originally I wanted to make a frame to set the plate on. The issue I saw was that the size of it would need to be 2" wider in all directions than the winch mounting area if I didn't want the mounting bolts to go through the tubing. I thought that would be a bad idea to prevent water from pooling inside the tubing and rusting onto my driveway. This lead me to follow Warn's style. After I was halfway done I thought I could have added some 3/8" 2"x2" angle iron along the edge and would still have some support without the hollow water trap, but that was after I got this far and warped it. So as I mentioned then came the warping and I pulled a Homer and realized I should have tacked it down well to something.I will be sand blasting and then coating it in a KBS kit to prevent rust then a top coat for UV protection. I also plan to take flat bar from the top of the hitch bar down to the plate - at the rear and sides to make a "mound" to help prevent lateral twisting. I'm just worried the only support is a bar welded to a plate. I like the angle Iron idea also on the bottom edge if I can get it flat.
Thanks in advance for all your help. I'm off tomorrow and look forward to figuring this thing out.
please pardon the Grammar, it's late and and I'm pretty tired after researching how to fix this the best way