Bickmore Kahl Hat Stiffener Spray for Felt & Fabric Hats - Restores Shape & Supports Brim - Will Not Affect Color, Tone or Texture - Long Lasting Results (Made in USA) Clear

You can try this product... https://a.co/d/00KR0H6R But I don't know if that's going to be enough. Or, there's a product called airplane dope. No joke. Hardware stores usually have it. I remember using it to make little ghosts out of cheesecloth when I was a kid. That would probably work pretty well for something like this.

https://a.co/d/007zbO7s