You must glue it mate, as the masking tape in time will move believe me. Masking tape is not made to be permanent heat, solvents and water will bring it off, remember it’s made for decorators to remove easily
Araldite standard epoxy is what you need to use.
When you wrap the blank with tape to build it up to the correct diameter leave an open spiral on the tape wraps so you epoxy can grip the blank. Depending on the gap you may need to put a lot of glue in there but it’s a must, In the old days most rod makers used string to build or bridge a gap it makes for a better job.
Once the string it glued to the blank you will never get it off and it’s not affected by any of the above.
Gary
Nicho Bamboo Rod Co