Can I shellac a Shofar?



I’m making a shofar factory. What do I need to know if I want to shellac the shofar once it’s ready for use? Is there an issue with shellacking the mouthpiece?



Shellac should prefer not to be used at all, due to chashash of shinui hakol, at least, not in the mouthpiece due to chatzitzah.



ראה דרשות הרמב”ן. ריטב״א ר״ה כז, ב.