Kiln Drying Gum

Sap Gum and Red Gum should be dried separately using different schedules. January 2, 2012

Question
Can you give us some pointers on the appropriate kiln drying schedule or initial settings (temp, EMC, fan speed) for sapgum (sweet gum - lots of heartwood)? We are attempting to dry approximately 20,000 bf of very wide 8/4. Air dried for approximately two weeks. I'm afraid to allow to air dry any longer, as we hear sapgum is easy to stain and stick shadow.

This is our first attempt with this species. My research shows that a T5-C3 schedule is best for this species/thickness. However my feeling is that this is just a bit too much humidity to start and maybe a T5-C4 schedule is better just to help make sure there is no staining or stick shadow (grooved sticks are being used). Temp, humidity, and fan speed are all easily controllable.

Forum Responses
From Professor Gene Wengert, forum technical advisor:
Lots of heartwood would be red gum. Red gum is prone to checking, so it must be mild. Sap gum needs fast drying (green from the saw into the kiln is best). It is best to avoid mixing sap and red.