Dean,

I have had a similar problem using Burmese teak and epoxy glues, the laminations and joints came apart all to easily. I lack the depth of experience with walnut, but I would be looking at the oil content of the wood as a contaminant. I got over the oily teak problem by not puting it under epoxy laminations and if absolutly necessary I degreased the glued surfaces with carbon tetra chloride. I know it is one of the more nasty substances but that what was used in the industry at the time. Suggest that a les volatile chemical is available. Trichloroethyene?? what ever it is in dry cleaning fluids. Be very carefull with these chemicals and get expert advice.

Don