I would like to know about the permanence of cyanoacrylate glue. One can expect 30 years or more from good quality PVAs (polyvinyl acetates). What do the cyanoacrylate glues offer for durability? -Raul
Kathy Hoelscher: Cyanoacrylate, or super glue, can be permanent; however, it can degrade with exposure to moisture or some solvents like acetone. If the project is stored in ambient conditions, it should be a permanent fix. If the project is stored outside or in an area with temperature or humidity swings, bonds can degrade.
Just like anything else, the quality of the super glue formulation can make a difference. Cyanoacrylates are inherently brittle so are susceptible to dropping and vibration, unless they are modified for more impact resistance like Gorilla Super Glue.
As for PVA glue bonds, they could theoretically withstand 30 years of exposure, depending on how the project is stored and the stability of the wood. If, over time, the wood dries out, warps or undergoes swelling and drying cycles with temperature and humidity swings, then this can put stress on the glue bonds and degrade bond integrity.
Cross-linking PVA’s like Gorilla Wood Glue are formulated to be more water-resistant than those that do not cross-link during cure and so can withstand more weathering. However, most aren’t waterproof, so — again — the lifetime of the bonds is going to highly depend on how they are stored.
Kathy Hoelscher is director of research and development at Gorilla Glue.
Chris Marshall: There are a lot of dynamics that impact a good glue bond, so quantifying an expected lifespan of a glue’s particular application would be tough. Think about it: sunlight, moisture, wood movement, chemical breakdown, original surface preparation and the wear and tear of the object’s use over time all will impact durability of glue bonds. The toughest all-around glue is probably slow-setting marine-grade epoxy. It holds tenaciously, fills gaps, is pretty much impervious to water and withstands wood movement well. Boat builders swear by it. If you want extreme durability, I’d probably go that route straightaway over CA glue, regardless of the application.