epoxies. 5 minute mostly useless, it sets too fast and does not penetrate the wood surfaces too deeply. strength is lacking compared to other epoxies. 12 to 15 minute epoxy are good epoxies, reasonably strong. 30 to 45 minute epoxies good for fiberglassing a wing or when you need extra time to mix spread and position components, extremly strong with good penetration into surfaces. the only way to break the bonds with the 12 to 45 minute is to cut it or top apply heat until it softens.