i'm new to body work but have been welding(tig mostly) a while, i am getting ready to redo the floor pans in my truck, help me with the process please, i have watched videos and noticed leaving a half to an inch overlap but i don't like overlap(moisture catchers), what is the proper procedure to abtain a complete but joint? and isn't that the correct way to finish the sheet metal? are there any complete youtube videos? any information would be helpful.

thanks dave