Now we are on to what can be the messiest part of the process, gluing the tubes into the blanks.
There are many options as to what type of glue you can use, I have tried super glue, two part epoxy and polyurethane. The one I find best and have used for a few years now is polyurethane (PU), I find it gives a stronger bond and because it expands when curing it can fill any small voids between the tube and the blank.
The first thing to do is prepare the tube, when you get them out of the packet they usually have a thin coating of grease. This needs to be removed and the outside of the tube roughed up slightly to get the glue to bond properly.
This can be done by wiping with a cloth and then giving it a light sand with fine paper. This works very well but if you are making more than a couple of pens it can be time consuming and make your hands ache. The method I prefer is to put the tubes in a container of cola for about an hour. This cleans the tubes up and slightly pits the surface. After about an hour tip the liquid away and rinse the tubes in warm water and dry.