I have a 36” wide loom. I learned to weave on a much narrower loom and had no tension problems with it. After I wove for a while on the wider loom, the middle section of the warp remained tightly and perfectly tensioned, but the warp threads on the edges became much looser. I wove two towels successfully, but when I started a stole on the same warp, the edges became so horribly loose that I had to stop after weaving about 10". What am I doing wrong?
One possible reason for this problem is that you wound the warp on the warp beam with uneven tension. This doesn’t sound like the cause since your tension was fine for two towels.
Let’s say, though, that you wound the warp on the beam with even but loose tension. Evidence for “even” would be that the warp on the beam looks like a cylinder with a consistent diameter throughout. In this situation, if you have draw-in, the warp threads become denser at the selvedges as you weave (evidence for this is that the fell curves up at the selvedges). Then when you beat, the edge threads are hit more by the beater and are therefore yanked tighter around the beam (where they are loosely wound) and become looser and looser at the fell. The solution: the warp must go on the warp beam evenly and tightly, with paper or sticks between the layers and at the same width as the warp in the reed. The wider and longer the warp, the greater the tension differences.