In any boatbuilding project it is necessary to use clamps to hold parts together while glue is setting up. Normally you’ll need a LOT MORE clamps than you have. But making clamps to hold smaller part together is simple and can be made from scrap material you probably already have on hand.
I got this from http://www.hanalima.com/tooltips_pvcclamp.shtml
Scrap length of schedule 40 PVC pipe with 1 5/8″ outside diameter and 1/8″ thick walls.
How to Make a Clamp
Cut a piece of PVC length into multiple 5/16″ wide rings.
Cut saw slot thru ring at only one place