TC-851 A/B Page 1 of 2 Date: 03/12/2021
For more information call BJB Enterprises, Inc. (714) 734-8450 Fax (714) 734-8929
www.bjbenterprises.com
RIGID POLYURETHANES
By BJB Enterprises. Inc.
An ISO-9001 Certified company
TC-851 A/B
78 SHORE D POLYURETHANE CASTING SYSTEM
TC-851 A/B produces a high impact rigid 78 Shore D material that is commonly used to make computer housings, models of all
kinds, artwork, and can also be used for electronic component encapsulation. It provides a working time of 6-7 minutes.
Low viscosity RoHS/REACH compliant
High impact rigid material Odorless, clean white color
1-2 hour demold time Excellent for vacuum or pressure casting
PHYSICAL PROPERTIES TEST METHOD TEST RESULTS
Hardness, Shore D ASTM D2240 78 2
Density (g/cc) ASTM D792 1.13
Cubic Inches per Pound N/A 25.2
Color/Appearance Visual White/Opaque
Tensile Strength (psi) ASTM D638 7,200
Tensile Modulus (psi) ASTM D638 2.1 x 10
5
Elongation (%) ASTM D638 8
Flexural Strength (psi) ASTM D790 10,300
Flexural Modulus (psi) ASTM D790 2.6 x 10
5
Shrinkage (in/in) linear 12 x x 0.005
Izod Impact, notched (ft-lb/in) ASTM D256 0.65
Heat Deflection Temperature @ 66psi ASTM D648 210 5 F (98.9 3 C)
Heat Deflection Temperature @ 264psi ASTM D648 195 5 F (90.6 3 C)
Note: Reported physical properties based on elevated temperature cured test specimens.
HANDLING PROPERTIES Part A Part B
Mix Ratio (by weight) 100 50
Mix Ratio (by volume) 100 51
Specific Gravity @ 77 F (25 C) 1.1 1.07
Color Pale Yellow Colorless
Viscosity (cps) @ 77 F (25 C) Brookfield 75 1,400
Mixed Viscosity (cps) @ 77 F (25 C) Brookfield 400
Work Time, 100g mass @ 77 F (25 C) 6 7 minutes
Gel Time 7 8 minutes
Demold Time @ 77 F (25 C) 1 2 hours
Properties above are typical and not for specifications.
TC-851 A/B Page 2 of 2 Date: 03/12/2021
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 C). 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:
TC-851 A/B with its non-mercury catalyst system does exhibit greater sensitivity to moisture than do similar products that use
mercury-containing catalysts. TC-851 A/B should be stored at ambient temperature and the TC-851 B component may
require vacuum de-airing prior to combining it with the A component. Evacuation of the mixed components is mandatory in
order to achieve best results. If further information is required, please contact BJB s technical staff for assistance.
STORAGE:
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
Quart Kits 2 lbs. 1 lb. 76
Gallon Kits 8 lbs. 4 lbs. 302
5-Gallon Kits 40 lbs. 20 lbs. 1,512
55-Gallon Drum Kits 400 lbs. 200 lbs. 15,120
SAFETY PRECAUTIONS :
Use in a well-ventilated area. Avoid contact with skin using 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.
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.
Refer to the Material Safety Data Sheet before using this product.
WARNING: This product can expose you to chemicals including 1,2-Benzenedicarboxylic acid, di-C9-11-branched alkyl
esters, C10-rich, which is 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.
Handling Guide