Make sure you crimp and put a lower lip on the original metal and seat the patch on that. It sits flush and you don't have to try and hold it in the correct place. Vice grip makes one
Doing that can create a spot for rust to start, that's why I butt weld all my stuff. Yea it's tricky an time consuming but it's worth it. Since you've already done it put some seam sealer on the joint