Some Longarm ladies put machine oil on their thread before quilting. The tension should pull most of it off the thread as you sew stitches. I have found that oiling the tension will help when the thread is shredding, rather than the entire cone. One time, it was just that cone of thread. The same color, a different cone, worked fine. One time, the thread was shredding because it was catching on a burr on the cone itself. I finally started watching the thread and I saw it. I changed the placement of the thread guide and solved the problem.