I reckon the best way to connect masts re later gaps or later sticking together is to rinse out the top half of the mast with clear water and then join it with the bottom half. Make sure to not put down either half after you rinsed them. Initially they'll want to pop apart due to the water sealing the air into the top and there being pressure if the top is sealed. One just wiggles and turns the top until most air has escaped and then slides the mast up the sleeve. Had never had a mast come apart or stick anymore after I adopted this method.
