There are two ways to make repairs: by replacing the warp thread completely (quicker) or by making a splice (the right way I say in my beginner book). Not sure I agree with that exactly. Locate the end of the broken warp thread that comes from the warp beam. If you can’t find it, use the replacement method. It’s usually easy to find the thread and its exact location in the heddles if you have the lease sticks behind the heddles. The “lease” (cross) is an enormous help in tracing where the thread goes in the heddles and then the reed.
The splice method:
Take a new piece of warp thread (several inches or more longer than necessary). Attach it to the broken end, take it through the heddles and reed. Then wrap it around a pin like a cleat onto the cloth. The break can be anywhere. If it is in front of the reed or in the heddle area, I would take the broken thread to behind the heddles and tie. It can hang up in the reed if it is in front of the heddles. In my Weaving for Beginners I show a more proper way. That is, to tie the new thread to the broken one as far back as possible with a bow. When the bow appears behind the heddles, undo the bow and there should be enough thread to go through the heddles and attach with the cleat to the cloth. USE A WEAVER’S KLNOT because it is a thin knot.
The replacement method:
Measure out a new warp thread a bit longer than the original warp. Attach one end onto the cloth with a pin like a cleat as in the illustration. Take the thread through the reed and heddles, exactly where the broken thread was, and hang it over the back beam with a weight.
Remember the hair comb trick from a previous post!