I'm getting ready to make my first bolster knife. I will use 416SS for the bolster and non-stainless steel such as A2, D2, or 3V for the blade. Do I need to apply some kind of sealer (glue) to keep moisture out of the bolster joint to prevent rusting? Also, I have several A2 knives with SS finger guards and rust is showing on the spine/finger guard joint where the gap was too tight for solder to penetrate. Any suggestions for this problem?