I do a lot of veneer layup (mostly red oak veneer) on plywood, MDF, and blockboards. The problem I am encountering constantly is the presence of blue stain (after hot-pressing the panel) in areas where there is putty on the panel surface (due to defects on the face veneer).
What is the most effective way to prevent blue stain from appearing when dealing with red oak veneer? Do we need to stack the panels after hot pressing to prevent moisture buildup (and causing the blue stain)? Also, what are the best ingredients for wood putty?
From contributor D:
Are you pressing using metal platens? Try separating panel and platen by using a paper/plastic interface. We find Tas oak reacts with moisture and metal contact and creates a blue stain. Physical separation by paper stops stain. Use a wood spatula for applying putty as well; steel spatula and putty react to create a blue stain.