Description

Shellac Sticks are a hard blocking compound which exhibits high adhesive strength and minimal shifting during processing.  Shellac Sticks are commonly used for blocking together a series of lenses or work pieces that are to be edged or profiled.  Other applications include thin film blocking, Blanchard wheel work, spot blocking, surface protection and a variety of uses where semi-hard, high tack materials are desired.  This material is very viscous when melted and should not be used where a thin film blocking material is desired. 

Application

Depending on application, Shellac Sticks can be applied in two basic methods:
Pre-melt Shellac Sticks in a controlled heating vessel, and apply or pour molten pitch to blocking plate or lap, and then mount the workpiece.
Pre-heat the blocking plate or lap and work piece, and wipe the pitch across the heated tool and mount the workpiece.
 
Remove the shellac by submerging in water above 168°F.  Clean the parts with a mild alkaline soap and warm water.  Any remaining residue is best cleaned by using Uniclear followed by acetone. 
 
For best results, please consult with UPI technical staff to recommend optimal processing conditions.

Benefits

• Unaffected by cool water, coolants or slurries
  
• Usable on a wide variety of materials
• High dielectric constant
• Lack of porosity

Physical Characteristics

• Ball Penetration Test (70F, 500 g weight, 1hr) (in): 0.0005 - 0.0010
• Softening Point (°C): 60 - 69
• Melting Point (°C): 69 - 77

Availability