Alright here goes nothin'.
This all started as a 14 year old young gentleman wanted to build himself an acoustic guitar but thought he would have to have hundreds of dollars in tools. And in a way he was right, that is unless you wanted to do it the hard way, my version of the hard way. Speaking of no money, let's make a guitar out of a fence board and a 2" x 4". No it will not turn out great or might not last too many seasons but the point was to get a person over the first guitar hump and they can build a good one with more confidence.
Had a 6" board, maybe use it for the top back and sides. Try using a handsaw to cut out the sections then resaw the board, split it down the middle.
That was doing it the hard way. The board sticking up out under the top pieces is the sides. I didn't notice the saw wondering away from center and ruined the one side. Enough of that, took the top to the table saw and cut all around, I have a small blade on it right now, then finished cutting it with a hand saw. Noticed the section that I was going to use for the back has developed a split slice cutting it around with the table saw
Wanted to know if you could clean up the wood with a small plane. The top one is unplaned the bottom planed. It works well enough but just flexing the wood I could tell the major weakness of the flat sawn section, the ellipse portion. So much for this wood. Learned it is not worth the trouble to use wood not suitable for instrument making. Not bad wood, just cut wrong.
But I am an inquisitive type. Is it really the flat sawn part really that floppier? I through the pieces through my drum sander and it seemed like the cathedral part just got planed off deeper and naturally was flimsier. I joined the two together, did not take a picture of the steps. I will have to do that with the back. In the picture I also have a 2" x 4" with the most common cut that is usable for us. I cut it in half and am going to glue the same side to itself to help counteract the movement of the wood in temperature and humidity changes. I grabbed the back and side wood from another board. It was not as good as the one I mucked up with the handsaw. I didn't want to bother going to Home Depot to get one piece of wood.