Those are very good hinges, but slightly more work to install. Some people drill through the surface to "pin" the hinges with toothpicks. But that is a lot of needless effort.

To insure that they can never come loose, I score the plastic with an Exacto knife about a dozen times on both sides, top and bottom parallel to the hinge pin, so the epoxy has something to grip besides the little molded in holes. I have had crashes where the hinges have been torn apart at the hinge pin, but have never had a hinge pull free from the balsa that it is glued to.

As to glueing, I fill a clear soda straw with the epoxy, flatten one end and insert it into the hinge slot. Then just squeeze a little into each slot. Then just wet the surface of each hinge and slide in. Definately use the vasoline on the pins before and very slow epoxy.

Here is a picture of a horizontal and elevator hinged with the Du-bro hinges. Can you see them?