Adhesives
Adhesives have trouble penetrating hardwoods due to dense cell structures and high levels of natural extracts. To minimise this effect:

• Sand joints lightly to break compressed cell walls before applying adhesives
  
• Glue immediately after machining joints to minimise extract bleed,
  
• Use sharp cutters to open up the cell structure thus creating better glue penetration,
  
• Use water based adhesives sparingly so as to not encourage swelling in timber - leave joints to dry as long as possible so swelling can subside before sanding flat.
  
• Do not use flexible adhesives such as PVA’s as they may fail due to the force brought about by moisture induced movement in joints – especially in high density timbers.