There is an epoxy product available that will bond just about every material imaginable to some other material -- even generally incompatible materials like wood and aluminum. Effective epoxy adhesives include two-part adhesives that have to be mixed together. For small projects, or if a small amount of epoxy is needed at one time, consider two-part epoxy products in a syringe that mixes together as it is dispensed. This is the easiest product to use for bonding aluminum to wood.
Be sure that the wood surface is free of contaminants like dust dirt, oil, grease and wood finishes like stain, wax and polyurethane. Also make sure the wood is strong and structurally sound.
Clean the aluminum with a degreasing cleaner. Metals are usually formed and processed with oil to ease the process and lessen friction. The oil, if left on the aluminum, will interfere with the bonding process. A good water washing should do the trick. If the aluminum needs to be scrubbed to get it really clean, use 00- or 000-grade steel wool to do the job. Wipe the excess water off of the aluminum, and allow the aluminum to dry.
Screw the syringe tip onto the epoxy container. Push the plunger to mix and dispense the epoxy at the same time. Place the epoxy where you would like to make the bond.
Press the wood to the aluminum and hold the two materials in place for a few seconds. Apply a clamp to the wood and the metal to keep the two materials together while the epoxy cures. Cure time will vary depending on the epoxy product used.
Remove the clamp 30 minutes after the cure time has passed.