In this post I will cover some of the basics of preparing your tube fly for tying on. It is a fairly simple task, so we will jump right in. Before I start tying some tube flies, I usually will prepare about 5-10 tubes so that I don’t have to stop after I have finished tying the first tube fly and prepare another tube, before starting on the next fly.
The first step would be to prepare one side of the tube by melting the liner on the tubing. This is accomplished by bumping the blue part of an open flame against tube liner. Leave about an 1/8 of an inch (3mm) exposed, this will be the part of the tube liner that will curl back forming a lip to help secure the tube into place.
Usually bumping the open flame against the tube liner 3-4 times is enough to do the job. If the lip on the liner tube is forming unevenly, it can be helpful to slowly spin the tube while bumping it with the open flame.
If you did this right, the liner tube should have curled back nicely making it so the liner tube can not slide back out of the tube (picture below).
I like to keep a bodkin, or one the pins from the tube fly vise adapter handy in case I have melted the liner too much. If you expose the liner tubing to the open flame for too long, it will begin to close up. If this is the case, quickly grab the bodkin and insert it into the hole before the liner tubing cools and hardens.
Now that you have one side of the liner tubing prepared, we will start on the other end. Melting the first side is always the easiest, because you have plenty of room for error. However, this time, we need to trim the liner tubing about an 1/8 of an inch (3mm) from the metal tube itself (pictured below). This will give us just enough liner to curl back and hold the metal tube snug in place.
In many situations you will only prepare one side of the tube before you start to tie on it, and then melt the other side of the tubing when you have finished tying your pattern on the tube. Usually this is done when you plan to add a cone head to the end of your tube fly, or perhaps if you want to transition to a smaller tube to help create a smaller head. If this is the case, be sure to leave a decent amount of tubing uncut so that you have some room to work as you are finishing the fly.
If you are having trouble with your thread sliding off the end of the tube as you are trying to apply your whip finish, it can sometimes be helpful to melt a little bit more then an 1/8 of an inch (3mm) on one end of the tube fly. This will create just a slight bulge around the end of the tube that will help keep thread from sliding off the end of the tube when applying your whip finish.
One last note would be junction tubing placement. When you begin to tie on your tube, make sure to start tying about a 1/4 of inch (6mm) from the end of the tube (pictured below), so that you have plenty of space to slide the junction tubing on the rear of your tube fly.
Now that the we have our tube prepared and ready to go, with 5-10 extra
prepped and waiting as well, lets place it on the vise and let our