OK. I think I know what you're trying to ask,but so far none of these responses will help without pictures,and an explanation of what's happening. I'm scratch building a four foot version of the X-wing that was shown in Return of the Jedi in my thread. This too,was a little over four feet in length.
If you watch this as it progresses,I'll try to explain the entire process,and why I'm doing all the stuff in the photos. I'll even offer a tutorial on gluing,and painting techniques,as well as weathering for beginners. Maybe that will help you understand scratch building a little better. I'm using a balsa fuselage,and I'll cover it with sheet styrene,and reinforce the insides with acrylic. I'll show the easiest way to make something like this,so that you can learn faster with fewer mistakes. I learned the hard way,and I hope to keep others like you from having to do the same.