Propolis Propolis Propolis or bee glue is a resinous mixture that honey bees produce by mixing saliva and beeswax with exudate gathered from tree buds, sap flows, or other botanical sources. It is used as a sealant for unwanted open spaces in the hive. Propolis is used for small gaps (approximately or less), while larger spaces are usually filled with beeswax. Its color varies depending on its botanical source, with dark brown as the most common. Propolis is sticky at and above , while at lower temperatures, it becomes hard and brittle. While foraging, worker bees primarily harvest pollen and nectar,
Resorcinol glue Resorcinol glue Resorcinol glue, also known as resorcinol-formaldahyde, is an adhesive combination of resin and hardener that withstands long-term water immersion and has high resistance to ultraviolet light. The adhesive, introduced in 1943, has been popular in aircraft and boat construction. Until the invention of epoxy resin, resorcinol was one of the most common marine glues. Unlike epoxy, it does not have gap filling properties, requiring joints to be close fitting and clamped under pressure to achieve good results. The glue comes in two parts — a red syrup and a light brown powder that were mixed to form glue.