Why is African Sumac not getting more red.?

[robert raess]

If i leave any chunks of the Af. Sumac outside or in the rain it gets deeply red.However when i put shellac and wax on it it does not.I haven't used a WOP,it's been my exp. that shellac[univ. sealer] will give wood a similar richness altho not quite as rich as Poly.I'm pretty sure it's photo-reactive type wood.Let me know if you have had a similar exp.?Thanks Rob

[Dan Forman]

Based on the evidence above and not having any actual knowledge about this, I would guess that it is not light but oxidation that causes the wood to turn red, as wax and shellac would act as a barrier to oxygen, but not to light. Again, just my guess.

Dan

[Dan Hintz]

Yep, it's UV-reactive... no suggestions on why it's not turning other than the shellac/wax has UV inhibitors. Maybe if you let it sit in the sun for a longer period of time?