You might think DAP Contact Cement is glue, like Elmer's or super glue. That's not quite the case, however. When you used Elmer's glue in elementary school, you put it onto one of the things you're gluing, stuck that to the other thing, and waited until it dried. DAP works differently.

DAP is a contact cement. What that means is that, when two surfaces spread with DAP come in contact with each other, they cement together and are very difficult to pull apart.

But DAP isn't just a cement; it's a cement in a liquid medium. That liquid medium is what keeps DAP from just being a block of hardened cement in the can. It's also what lets you spread it on your surface.

Once DAP has been spread on a surface, the liquid starts evaporating, allowing the cement to start bonding to itself and the surface it's on. The more that liquid evaporates, the better it's able to make its bonds. Once it's dry, there's nothing left keeping it from bonding to itself. That's when you bring the second surface, also treated with a dry application of DAP, in contact with the first. It'll bond with the cement on the other surface instantly. Fast like you better have your aim right on the first shot; you may not have time to correct it before it's stuck. You know it's dry enough to stick to itself when, if you touch the surfaces, it doesn't feel sticky or wet or tacky to you (unless there's DAP on your skin... then it'll stick to that!).

I've found that it takes the liquid about 20-30 minutes to evaporate, depending on weather and ambient temperature. I've gotten lucky with 15 minutes on a hot, sunny, dry day.

So, that said, how do you use DAP?

1. Spread a thin layer of DAP on both surfaces that you are going to stick together. It should be just enough DAP to cover the surfaces; if you put on extra, it will just take longer for the liquid to evaporate.
   When applying the DAP to your surfaces, it helps to allow the cement to soak into the foam a little. Lightly sanding the surface prior to application helps this.
2. Wait for the DAP to dry. Remember, DAP is cement in a liquid medium; if the DAP is still wet to the touch, there is still some of that liquid medium left that needs to evaporate. Unlike normal glues (i.e., Elmer's), DAP will not stick properly while it is still wet.
   Of course, you don't want to wait *too* long, either. You want to catch the DAP just at that point when it becomes dry to the touch.
3. When both surfaces are dry to the touch, press them together. Be careful to line them up properly - they'll stick together permanently, so you'll only get one shot!

And voila! You now know how to use DAP Contact Cement. Now, go build your sword!

(These comments are the product of a post by Seiichrio on the Dagorhir boards, which has been heavily edited and expanded by Alric of Drentha.)