I've been repairing the shellac finish on paneling in my home, and some spots are coming out way too flat when dried. In this photo you can see how the glossiness isn't consistent, even though I applied fresh shellac over all spots within the border. Luckily this spot is barely noticeable since it's near the floor, but I'm afraid to try anywhere else.
I'm using Zinsser Amber Bulls-eye, thinning it down with an equal part of denatured alcohol. Is the problem that I'm over-thinning it?
Or can moisture cause this? The finish in this flat spot was turning milky as it dried, which I read can be caused by excess humidity or moisture. I reapplied shellac several times until it dried without turning milky.
The original finish is around 30 years old and gets scratched very easily.