Wood – wood glue open time

adhesivewood

I am a total noob at woodworking. But I wanted to glue two pieces of pine wood together. After some research I realized that titebond (I,II, or III) might be what I want. I see here that the glues have an open time of 5 min or 10 min. From

What is open time, working time for adhesive?

it seems that open time is the amount of time that you need to wait before clamping the pieces of wood. So I would apply the glue to one (or both?) piece of wood, wait 5 (or 10) min, then make contact and clamp.

But from various Youtube videos it seems that the opentime is the same as working time. That is, the amount of time that it "allows" you do wait before clamping. (For example this video.)

At the end of the day, I would like to know how long I have to wait before making contact when using Titebond II.

Best Answer

Open Time

"Open time" is used in two different ways. For contact cements, it is the minimum or optimum time to leave the glue exposed before joining the pieces, because you want the adhesive to partially dry first. For wood glue and most other adhesives, it's the maximum time before joining the pieces because the surface starts to dry or cure and bonding degrades.

Working Time

"Working time" is how long you can reposition the pieces after you join them without affecting the ultimate bond.

Working time is often different from open time. With many adhesives like wood glue, you depend on the glue being very liquid to absorb into the material surface. However, the glue will bond with more of itself even after it has started to dry a little. So once the glue is adhered to the wood, you have a longer period in which you can move the parts around.

For some wood joining, this characteristic is used for stronger joints, especially on larger areas. A thin layer of glue is applied to both pieces, which starts to absorb into, and bond with, the wood surface. This allows more to be absorbed than might be the case if you immediately clamped the pieces and squeezed out most of the glue. While the glue is still in its working time, another layer of glue is applied to one of the surfaces and the pieces are joined. The second layer is in contact with glue rather than wood, so water (or other solvent) isn't being sucked into the wood, and that provides more working time. The solvent in the additional layer also extends the working time of the first layer.