Welding Tips and Tricks

Hello,

I am new to welding. I am mig welding a 16-guage box for a grill out of hot-rolled steel.

Noticed this gap after I had welded two sides. Did not tack weld.

https://plus.google.com/photos/photo/10 ... 4_Hx-K7GJQ

What would you do to prevent this?

To much heat in your part. I'd stitch weld it and let it cool a little between runs. Ex 2in weld on the left side, then the same on the right side, then the middle. After that I'd let it cool then repeat the process until you got it all welded.
Or if you have a metal table tack it to the table then cut it loose when done

Just lay racks around the perimeter before welding. 16ga is pretty thin and will distort heavily if you just blast it and go-

I'd also stand it up and do the welds vertical down, relatively quickly.

I like the idea of stitching. Also, weld the northwest side first, the southeast next, with cooling in between, that should even out the heat. Yeah, I blasted this one, beginner's enthusiasm. I had heard metal could warp, found out the hard way, but, hey, that's how you learn. Good suggestions, everyone!