I am in the process of building a boat out of strips and I am using an inexpensive yet effective of holding the strips in place.
I am using old bicycle tubes with the valves cut off and the tube cut to make it a nice long elastic. I have found that the very skinny road bike tires work well. I simply clamp or tie one end off. Then wrap the tube firmly around the pre-glued strip. I dry fit each strip first. I also use latex surgical tubing, but I had to buy that. And I have a good supply of old bike tubes.
Should you not have a collection of old bike tubes , try asking a local bike shop to save some for you.