I do not know this for a fact but wouldn't be surprised to learn that some of the newer Turkish offerings have adhesive bonded barrels and ribs.
For those of you more in the know what would be the advantage of using an adhesive? Would there be some sort of release agent that could be used to take the barrels apart for repair, if needed? I cannot imagine it would save a tremendous amount of money. Same prep time for the barrel set and some of these newest adhesives, such as Belzona, are astronomical in cost.
