WC-766 A/B Page 1 of 2 Date: 03/22/2022
For more information call BJB Enterprises, Inc. (714) 734-8450 Fax (714) 734-8929
www.bjbenterprises.com
WC-766 A/B
WATER CLEAR 65 SHORE D
URETHANE CASTING SYSTEM
WC-766 A/B is a two part, clear, colorless 65 Shore D urethane castable product that is commonly used to make clear or tinted parts
of all kinds. When used at room temperature, castings 1/8″ thick or larger can be readily cast. Castings that are less than 1/8″ thick
generally require a mild post-cure.
Exceptional clarity Impact resistant 15-minute work time
No odor Good weatherability
PHYSICAL PROPERTIES TEST METHOD RESULTS
Hardness, Shore D ASTM D2240 65 5
Density (g/cc) ASTM D792 1.08
Cubic Inches per Pound N/A 26.4
Color/Appearance Visual Colorless/Clear
Tensile Strength (psi) ASTM D638 4,600
Tensile Modulus (psi) ASTM D638 3.1 x 10
4
Elongation (%) ASTM D638 225
Flexural Strength (psi) ASTM D790 315
Flexural Modulus (psi) ASTM D790 2.9 x 10
4
Tear Strength (pli) ASTM D624 460
Shrinkage (in/in) linear ASTM D2566 0.004
Izod Impact, notched (ft-lb/in) ASTM D256 8.9
HANDLING PROPERTIES Part A Part B
Mix Ratio by weight 75 100
Mix Ratio by volume 72 100
Specific Gravity @ 77 F (25 C) 1.08 1.03
Color Colorless Colorless
Viscosity (cps) @ 77 F (25 C) Brookfield 650 550
Mixed Viscosity (cps) @ 77 F (25 C) Brookfield 650 50
Work Time, 100g mass @ 77 F (25 C) 15 minutes
Gel Time 20 minutes
Demold Time @ 77 F (25 C) 6 8 hours
Properties above are typical and not for specifications.
ALIPHATIC & WATER CLEAR URETHANES
Dedicated to QUALITY, SERVICE, SAFETY, and INNOVATION
An ISO-9001 Certified company
WC-766 A/B Page 2 of 2 Date: 03/22/2022
For more information call BJB Enterprises, Inc. (714) 734-8450 Fax (714) 734-8929
NON-WARRANTY “Except for a warranty that materials substantially comply with the data presented in Manufacturer’s latest bulletin describing the product (the basis for this substantial
compliance is to be determined by the standard quality control tests generally performed by Manufacturer), all materials are sold “AS IS” and without any warranty express or implied as
to merchantability, fitness for a particular purpose, patent, trademark or copyright infringement, or as to any other matter. In no event shall Manufacturer’s liability for damages exceed
Manufacturer’s sale price of the particular quantity with respect to which damages are claimed.”
CURE SCHEDULE/HEAT CURING:
Most of the physical properties can be achieved in 5-7 days at 77 F (25 C). You may use your own post-cure schedule but the
physical properties may vary from BJB s cure schedule of 1-3 hours at 77 F (25 C) followed by 16 hours at 160 F (71). Do not
exceed curing temperatures of 200 F (93 C). Support of the part may be required to prevent part deformation during the heat curing
process.
NOTE:
The cure may be inhibited if cast against a tin catalyzed silicone RTV.
STORAGE AND HANDLING:
Store at ambient temperatures, 65-80 F (18-27 C). Unopened containers will have a shelf life of 6 months from date of shipment
when properly stored at recommended temperatures. Purge opened containers with dry nitrogen before re-sealing.
PACKAGING Part A Part B
Cubic Inches
per Kit
Gallon Kits 6 lbs. 8 lbs. 370
5-Gallon Kits 30 lbs. 40 lbs. 1,848
SAFETY PRECAUTIONS:
Avoid contact with skin. Use protective gloves and protective clothing. Repeated or prolonged contact on the skin may cause an
allergic reaction. Eye protection is extremely important. Always use approved safety glasses or goggles when handling this product.
Use in well-ventilated areas. Avoid breathing vapors. If exposures cannot be kept at a minimum, a respirator may be necessary in
addition to ventilation. The use of a positive pressure air supplied respirator is mandatory when airborne isocyanate concentrations
are not known or exceeds OSHA S TWA of 0.005 ppm. Air purifying, organic cartridge type respirators are not generally
recommended to use when handling this material without implementation of an end of life service program. Observe OSHA
regulations for respirator use (29 CFR 1910.134). Employers are responsible for selecting the correct respirator for each situation.
IF CONTACT OCCURS:
Skin: Immediately wash with soap and water. Remove contaminated clothing and launder before reuse. It is not
recommended to remove resin from skin with solvents. Solvents only increase contact and dry skin. Seek qualified
medical attention if allergic reactions occur.
Eyes: Immediately flush with water for at least 15 minutes. Call a physician.
Ingestion: If swallowed, call a physician immediately. Remove stomach contents by gastric suction or induce vomiting only as
directed by medical personnel. Never give anything by mouth to an unconscious person.
WARNING: This product can expose you to chemicals including Phenyl mercury acetate, Naphthalene, and 1,2-
Benzenedicarboxylic acid, di-C9-11-branched alkyl esters, C10-rich, which are known to the State of California to cause cancer
and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.
Refer to the Material Safety Data Sheet before using this product.
Handling Guide