Gluing Tips

  • Think about how to maintain pressure while the glue cures. The simplest way is a clamp, but for irregular shapes, or pieces that are far from an edge, it can be difficult for a clamp to reach both sides. If the pieces are flat you may be able to stack them and put a weight on top
  • When possible, do a dry fit. Assemble your piece without glue, including figuring out how to use the clamps. Then take it apart again, apply glue, and clamp it again.

Wood Glue

  1. Wood glue (“yellow glue” – aliphatic resin, a kind of PVA) is water-based. A piece of wood that has wood glue applied to it will swell slightly. This effect is strongest in MDF and weakest in plywood, but it still happens to plywood. A piece that fits into a slot without glue may not fit into the same slot once glue has been applied.
  2. Wood glue is not gap-filling. It only joins two pieces that are in tight contact. If there is a space between the pieces, and you fill the space with wood glue, this will not hold. (There is another glue, epoxy, that can fill gaps.)
  3. Glues have an “open time” (during which you can move the pieces into a position), a “clamp time” (during which they need to be clamped), and a “cure time” (before the glue completely sets – the piece can be unclamped and moved around during this time, just don’t apply any stress to the join). Wood glue’s open time is five minutes. This is how long you have after you apply the glue, before you clamp it. This is why you do the dry the fit.
  4. Wood glue does not stick to dry wood glue. If you have to undo a joint and start over, you will need to scrape the old glue off.
  5. Wood glue cleans up with water before it cures. Afterwards, you can scrape it off. If you apply enough glue, there is “squeeze out” from the joint, onto surfaces that are not glued. You can wipe the glue off from these surfaces before it cures, or scrape it after an hour. You can also use blue tape to protect surfaces from squeeze out. Then you can peel the tape off instead of wiping or scraping off the glue.

Hot Glue

Hot glue sets so quickly you can often just hold the pieces in place. (Make sure you don’t burn yourself!)

Hot glue is weak. It is appropriate for a small piece that is not load bearing, or to hold two pieces together while a slower glue sets or you use fasteners.

Hot glue is visible. This doesn't matter if the joint is inside a pocket or otherwise out of sight. Also you can decide that you want people to see the glue, and use colored hot glue or mix in glitter or other filler.


Shorter guides: