35815-01-500
Dug writes –

X-Treme Tape forms an air and water-tight seal, is heat-resistant up to 500 degrees F, and insulates up to 400 volts per mil. Woodworkers have found a use for this elastic silicone based tape when gluing odd-shaped pieces.

Woodworkers Journal eZine – Tool Maker Insider – [via] Link.