If it is your rub rails causing the problem.......
All I have ever used is the 1 1/2 inch by 1/4 inch pine lattice from home depot.... I can get it in lengths that does not require any joints and it works like a dream for me. Down here they have them to 18 feet , one solid piece.
The outside one is one solid chunk from the bow to the stern. The inside one is built up on some spacers placed between the ribs and cut to fit.
Normally the spacers are one of the pieces of the 1 1/2 by 1/4 lattice stripes cut into 3 inch pieces and placed a short distance apart ... normally about 2 inches. Then the inside rail is epoxied to them after careful measuring creating a solid inside rail.
Look at it this way...... The boat is , or I assume , yours is 1/4 inch wood .... then a 1/4 inch rail on the outside will make that 1/2 inch... Now add some spacers on the inside ... say 1/4 inch ... so now we are looking at 3/4 of an inch. Add to that a 1/4 inch inside railing and you have a full inch on the rails or the make up and support for the rails.
:wink: The 1st boat is a learning process and in more then one way. The great thing is it gives you one to use while you think about the others running threw your mind and how to do them.
Chuck.