About 5 years ago I built 18 sashes of VGDF windows to match those original to the house. The original 1939 glass was bedded and the millwork was painted under the glazing. For the new sash, I pre treated the rabbets with copper green and painted over that. I used Dap 33 to bed and glaze. Everything's fine so far, but I'm in sunny so-cal so no hard weather here..!