sheetmetal bed questions

the next thing coming up is sheetmetaling my bed and tubing it... im gunna be rolling it with 18 guage sheetmetal but my problem is i cant do it all in one sheet... id have to do it in two.. is this a very common problem? what precautions should i take to make sure when i go to paint it that i wont see the seem ? i know most of that is going to be the body man but what can i do to make his job easier to make it the smoothest possible? any tips/tricks things to watch out for would be awesome.. thanks

-pascal