Do you ever get confused about what type of glue to use? Many glues claim to stick anything and everything together. It can be hard to say which is best for a specific job. Here are some of the more common glues and their uses.
Carpenter’s Glue or PVA Glue
(polyvinyl acetate) is one of the most common types of glue. If you have kids, or ever were a kid, you’ve probably used an everyday PVA – Elmer’s White Glue. PVAs provide a strong bond on porous surfaces but do not adhere well to nonporous materials such as metal or plastics. Yellow glues such as Titebond are perfect for woodworking but have you had the experience of regluing a loose spindle on a chair only to have it fail almost immediately? That’s because PVA’s do not stick well to other glues. For wood furniture repairs you will want to use Hide Glue. (See below.)
Polyurethane Glue
is waterproof and will adhere to wood, metals, stone, ceramics and many plastics. Rather than ‘drying’ like PVAs, it reacts chemically with moisture, expanding and filling voids to create a very strong bond. It has a longer open time, giving you more time to position and clamp. A common example would be Gorilla Glue. Sounds like the perfect glue, but there’s a dark side; it’s that expansion thing – excess glue will bubble out of your glue joint and coat the surrounding area. And it’s not water soluble so you can’t just wipe it off with a damp rag; you have to sand or cut the excess off. Consider wearing gloves since once it has dried even solvents won’t remove it – you have to just let it wear off.
Hide Glue
unsurprisingly, is made from animal products. It is the glue of choice for furniture makers because of its relatively long setting time, non-creeping, tacky grip, and because unlike most other adhesives, it can be reactivated with moisture. For furniture repair you can even steam off the old glue. Of course this is also why furniture stored in damp locations often begins to fall apart. An excellent choice for wood and furniture repairs but be aware that it has a relatively short shelf life once opened.
Super Glue or CA Glue
(cyanoacrylate) is a fast bonding and tight holding glue which is appropriate for almost any project. Super glue will bond metal to wood, wood to wood, metal to metal and many other materials together in seconds. It holds for a long time and is not susceptible to extreme heat or cold. CA glue is also very good at bonding skin, and while this can be a troublesome side effect during everyday use, it can form a quick, painless bandage.
Be sure to choose the right glue for your project. Unfortunately, we have run out of space long before we ran out of glues. Epoxy, hot glue, spray adhesives, contact cement, resin glues, model and hobby cement… more on those next time.
