I've recently started using Total Boat Penetrating Epoxy for potting the wire coils on the pickups I build. It's a very low viscosity epoxy, made for penetrating and reinforcing rotted wood. It also has no VOC's (nasty solvents) and almost no odor. Very pleasant to work with indoors. And not terribly expensive; $38 for 1.5 pints.
This might be a really good product for heavy pore-filling in woods like ash. It's normally very clear, but I assume you could add pigments to tint it. I haven't done much filing or sanding of it yet, but it appears to be about the same cured hardness as West Systems. I normally do my pore filling with West Systems, and I assume this Total Boat product could be applied and sanded the same way. It may even sink in deeper than the West Systems.
https://www.amazon.com/dp/B0141F71II/ref=twister_B00J36WRRG?_encoding=UTF8&psc=1