Loon Hard Head is the best non-toxic odorless cement on the market. Loon’s Hard Head Fly Finish replaces messy fly tying epoxies in most applications, and is perfect for building colorful, glossy heads and bodies easily on flies like steelhead and salmon flies as well as bass, pike and large musky flies. Comes in a variety of colors and shimmers making it easy to create just the fly you want.
Hard Head also comes in Phosphorescent (glow in the dark), you can charge the head with a bright flash light or a UV light. And it comes in Fluorescing which has UV in it that reflects with the UV in natural light to become more visible to fish.
Here's a tying tip. When using the Hard Head Pearlescent colors shake the bottle adequately as the product will separate if left sitting for a while.