Duct tape will work, BUT you got to remove the glass and tape while the glass is still warm. Otherwise it's a PITA to remove. The heat from the glass curing makes the tape adhesive gummy. Remove it while it's gummy.
If your dead set on putting just the 6 1/2 in there. I would cast it in two pieces. I would cast the cover for the front of the enclosure. Then do the ski hole area, and glass the two together. Then you could bolt the enclsoure to the gasket in the ski hole area. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
If your dead set on putting just the 6 1/2 in there. I would cast it in two pieces. I would cast the cover for the front of the enclosure. Then do the ski hole area, and glass the two together. Then you could bolt the enclsoure to the gasket in the ski hole area. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif