Tighter joints might be a easier to achieve if the strips had a slight bevel cut on them to start with, using a table saw. Someone mentioned 11 degrees on an earlier message.

I'm building a model kayak using strips with bevels ranging from about 8 degrees on one edge only to about 12 degrees on both edges, and fitting the outside tight is going well.

Too much bevel can cause cracks to open up when sanding.

John C