|Here’s how to repair a broken warp thread. Cut a piece of warp yarn that matches the broken end, about the length of the loom’s depth, maybe a little longer if the loom is small. Whether I begin working on a repair at the front of the loom or at the back depends on where I noticed the break.
If I’m working at the front of the loom (the broken end is in front of the shafts), I first isolate the offending thread and tie the splice thread to the end of the broken end (I like to use an overhand knot–Figure A). Anchor the other end of the splice thread to the woven cloth with a pin like a cleat (Figure B). Then, pull the splice though the dent in the reed and heddle to the back of the loom. You can avoid manually threading through the reed and/or heddles by pulling the original warp end with the splice connected to it through them.
Pull the splice toward the back of the loom as far back as you can-through the lease sticks and close to the warp beam. With the splice and the original warp still connected, tie a slipknot at the back of the loom as shown in the the box below. See how to tie the special slip knot and how to undo it. Go to the front of the loom and re-adjust the tension of the warp thread on the pin in the woven cloth. See Figures C and D. The reason to tie the slipknot is that it will be easy to undo when it appears just behind the heddles. See Figure E. At that time, undo the slipknot and pull the splice connected to the original warp thread through the heddles and reed to the cloth and tension it on a new pin used like a cleat. You’ll be winding the original thread on the pin, and the splice thread will no longer be used. See Figure F.
|Instead of using the slipknot, you can replace the overhand knot with a big bow. It works fine, but won’t be as easy to undo as the slipknot. Another method is to weight the splice thread and let it dangle behind the back beam as you weave. When the original thread is long enough to go through the heddles and reed, attach it to the woven cloth on a pin. See Figure G.
|If the break is behind the heddles,connect one end of the splice thread to the broken warp end with an overhand knot and tie the slip knot (see above) as close to the warp beam as you can. Then, it’s quick and easy to find the empty heddle by pushing the threads on either side of the broken thread apart at the lease sticks and working the separation up toward the shafts. I drape the splice thread on top of the warp at right angles to the warps so I can easily see it from the front of the loom, and then I thread it through its heddle while I’m sitting at the front of the loom. See Figure H.
With the same separating motion at the front of the loom,you can quickly find the correct dent, pull the thread through the reed, and anchor the splice thread in the cloth with a pin like a cleat. See Figure I below.
|When the slipknot advances, continue weaving until the slipknot has moved forward to the back of the shafts. See Figure E. Then, stop and undo the slipknot as shown in Figure L in box below. By then, the original thread will be long enough to be pulled through the heddle and reed, and pinned like a cleat into the cloth Figure F. Resume weaving and never think of that warp thread again.
Instead of knotting the threads together behind the heddles, the splice thread could simply be clamped to the warps on either side of it as far back from the heddles as possible. A good clamp is a hemostat, a clamp-like instrument that surgeons use. See Figure J. When the hemostat advances to just behind the heddles, you can unclamp the warp and draw the original thread through the heddles just as though you had done the slip-knot procedure. Use small hemostats that are about 6″ long or so.
Tie a slip knot to take up the slack in a spliced thread
Pinch the splice thread and the broken thread to form a loop of the excess thread. Use the two threads in the loop together as one thread (the tail) to tie the slipknot. See Figure K. Make a loop in the excess thread by crossing the tail on top of the pinched threads. Reach through the loop and grasp the tail pulling it to form a second loop. Tighten the knot by pulling the second loop away from the pinch. To loosen the slipknot, pull the two threads in the tail in opposite directions. See Figure L. In order for the slipknot to hold, it is important to tie the slipknot using only the excess thread you’ve pinched off.
–Halsey, Mike and Youngmark, Lore, Foundations of Weaving. David & Charles Ltd. England, 1975.
More information is in Weaving for Beginners.
The above tip is an excerpt from Book 3: “Weaving and Drafting Your Own Cloth“. It is from the Troubleshooting Chapter.