Dow Corning® Vacuum Grease. The standard sealant for hanging, sitting, and sandwich drop vapor diffusion setups. Stiff, non-melting, non-drying silicone sealant maintains its consistency from -40° to 260°C. Chemical-resistant and non-carbonaceous. Squeeze the grease into a 10 cc syringe fitted with a 200 µl pipet tip trimmed to desired diameter and you are ready to grease.