Many of us use epoxy in fly tying and rod building. There is a company by the name of Starbond. Most notably, they are known for their CA glue that’s used in the wood turning community. They offer various viscosities and large volume bottles. I like the medium thin formula for fly tying.
I’m digressing… Starbond also offers a 5-Minute Epoxy that is flexible-toughened, UV-resistant and non-yellowing. I feel these three qualities would be an asset to fly tiers. This is not a rod building thread coating product.