INSTALLING THE KOGATANA INTO THE KOZUKA USING A MATSUYANI GLUE (KUSUNE 薬練)
THE KOZUKA THAT HAD THE KOGATANA INSTALLED
Most kozuka that I had come into contact with that had the kogatana were either loose or just placed with a bent nakago to wedge itself within the kozuka. This would surely be unsatisfactory for such an utilitarian knife. About a year ago or so I had asked several fora about the traditional way that kogatana were installed into kozuka. I received much help from Andy Guy who had already used this method. It worked great and I put an excerpt below for those who might need it. I found the boiling temp of water low and thus the rate of dissolving slow. So I used direct heat to increase the temperature of the mixture and save time. The safest way to heat the mixture is boiling water though since it is flammable at high temp. The natane oil is actually used as a food oil and not toxic. I can't say the pine resin isn't but wouldn't be high on the list.
ANDY GUY'S RECIPE