Loctite 350 Ultraviolet Glue Loctite "350" ultraviolet glue is a medium viscosity adhesive that forms tough, flexible bonds with excellent adhesion to glass and metals. Strength retention is excellent when exposed to water or humidity. The product has a long open working time, making it ideal for fitting mineral or sapphire crystals. Cure rate and depth cure will depend upon light intensity and light source. Cures crystal clear. 50ml bottle. Not recommended for gluing plastic crystals. Highly recommended to be used with UV Lamp 12-209.