My house is 20 yrs old, in the Central Valley of N. Calif. I've got a
couple fascia boards (2X6 fir) that are showing age: the ends have
split a bit and look a bit ragged. There isn't' any major rot or
deterioration yet.

I plan to srape the paint off, sand smooth, fill the gaps and rough
spots, prime and re-paint.

Q: What is the best exterior wood filler for this use?

Thanks a heap
-Zz