I'm remounting a basement window whose glass was broken recently. The window hinges at the top and swings inward toward the cellar, and the top & two sides of the window butt up against the wood frame when closed. However, the bottom butts up against nothing. Under that bottom edge is cement or cinder block. The previous owner created what looks like toe molding using some sort of stuff that's crumbling now. I could buy toe molding and paint the bejezus out of it so it stands up to rain & snow, but I'd rather not drill into the cement to attach it. So, I'm thinking of covering that bottom edge of the window with waxed paper temporarily (so goop won't stick while curing) and creating "molding" using some sort of goop....but what kind? Let's assume that I can scrub the cement surface in any way necessary so whatever compound I use will adhere nicely.
What's the goop?