[ehaskins]

Thin CA will wick into the grain of thin veneers acting as a stabilizer. Epoxy is thicker and doesn't penetrate as deeply.

There are methods to get epoxy deeper, but they require significant equipment. Search for "stabilized wood" if you're curious.

[UniverseHacker]

I don't think that is true- I build and restore both wooden and fiberglass boats with epoxy, and have used it in almost every possible way. There are different thicknesses of epoxy with different properties, but the ones specially designed for penetrating deeply into wood - such as clear penetrating epoxy sealer will indeed penetrate extremely deep into wood, the manufacturer claims 9-16". In practice, almost any epoxy will penetrate at least 1" into wood.

If anything, epoxy often has too much penetration, and I end up doing a first coat or two that disappear fully into the wood, and another thickened one so it actually stays on the surface or joint.