ShelfYears

Does wood glue expire?

Titebond publishes two years for most of its wood glues and then says the useful thing out loud: that number is a conservative minimum, and the real test is whether the glue is still fluid.

Updated

Wood glue
Sealed
2+ years
Opened
Until it thickens
PVA COALESCENCE
Degraded performance

Sealed: 2+ years Tier 1

Titebond's own FAQ states the shelf life of a majority of its wood glues as two years, and defines shelf life as a conservative estimate of the minimum time a product should remain usable when stored as directed. It then goes further than most makers will: most of its yellow and white glues, including Titebond Original and Titebond II, remain usable beyond two years, and Titebond III stored at room temperature is expected to last beyond its stated shelf life.

After opening: Until it thickens Tier 1

Titebond does not publish a separate opened figure because it publishes a test instead. As long as Titebond Original, Titebond II and Titebond III remain fluid, without a drastic change in appearance, they will continue to perform as intended. The bottle ends when the glue changes, not when the calendar does — and what shortens that is water escaping past a crusted cap, or a cold night in an unheated shed.

How to tell it's gone off

  • Titebond Original that has gone thick and stringy — the maker's own sign that the glue is no longer usable.
  • Titebond II that has turned into an orange-colored gel — the second published stop sign.
  • Glue that pours in lumps, or grit and rubbery seeds in the bottom of the bottle.
  • A plug of dried glue in the spout that keeps rebuilding after it is cleared.
  • Glue that has gone thin and watery with a separated layer on top and will not shake back together.

If you use it anyway

Degraded performance

Old wood glue makes a joint that lets go; it does not harm the wood. Titebond is unusually blunt about the line: while the glue is still fluid and looks normal it performs as intended, and once it is thick and stringy or gelled it is finished. Use the finished stuff and the glue-up pops apart later, and the parts have to be cleaned back to bare wood and done again.

Why it goes off — PVA COALESCENCE

Yellow wood glue is a water-based emulsion: solid polyvinyl acetate particles suspended in water, which fuse into a film as the water leaves the joint. Anything that pushes those particles together early does the same thing inside the bottle. A hard freeze forces them into contact; water lost through a badly sealed cap concentrates them; years of slow change gets there eventually. The result is what Titebond describes — Original goes thick and stringy, Titebond II turns into an orange-colored gel — and once the polymer has coalesced, no amount of shaking or thinning brings it back.

Every page here commits to one of four states — Harmless · Degraded performance · Equipment damage · Safety issue. How the verdicts work.

How to store it

Titebond's condition is room temperature, stored as directed — that is what its two-year minimum assumes, and what Titebond III's longer life depends on. Gorilla's instruction on its wood glue is the same in plainer words: store in a cool, dry place, wipe excess glue from the spout, and keep the bottle sealed. A crusted spout is a cap that no longer seals, which is how a bottle dries out from the inside.

Sources