Fresh Cut Scarf, Ready for Squeezing Published October 26, 2010 at 2048 × 1536 in Sill Crazy After All These Years ← Previous Next → Fresh Cut Scarf, Ready for Squeezing We cut a lot of bladed, or keyed, scarf joints at PTF. The key keeps the sill from twisting and joints from opening. This photo shows the the first fitting of the center and right pieces of sill.