水性シンナー

I was worried thinning my head cement would make it stringy, but a couple drops of this and it flows perfectly without losing any hold. The water-based formula means no harsh fumes while I'm working at the bench.

A few drops of this in my head cement and it went from gluey to perfectly workable. My flies are coming out with way cleaner thread wraps now that I'm not fighting thick cement.

Wish the dropper tip was a bit finer, since it's easy to overshoot when you're thinning a small batch. That said, it mixes into my head cement cleanly and dries without any cloudy film.