by | Sep 27, 2025
TC-5024 A/B Page 1 of 2 Date: 07/18/2022
For more information call BJB Enterprises, Inc. (714) 734-8450 Fax (714) 734-8929
www.bjbenterprises.com
TC-5024 A/B
25 SHORE A SILICONE ELASTOMER
TC-5024 A/B is a two-component, room temperature curing silicone elastomer. This system is designed primarily for making
molds, but is also used for gaskets as well as a wide variety of parts. This product is a condensation cured system using a tin
catalyst that provides a 30-minute work time with a 4-6 hour demold time.
Excellent physical properties with high tear
resistance
Fast demolds
Provides excellent detail reproduction Cures against various clays including Roma
PHYSICAL PROPERTIES TEST METHOD RESULTS
Hardness, Shore A ASTM D2240-04e1 25 5
Density (g/cc) ASTM D792-00 1.21
Cubic Inches per Pound N/A 23.2
Color/Appearance Visual Blue/Opaque
Tensile Strength (psi) ASTM D412-98a(2002)e1 590
Tensile Modulus (psi) @ 100% ASTM D412-98a(2002)e1 44
Tensile Modulus (psi) @ 200% ASTM D412-98a(2002)e1 144
Tensile Modulus (psi) @ 300% ASTM D412-98a(2002)e1 280
Elongation (%) ASTM D412-98a(2002)e1 350
Tear Strength (pli) ASTM D624-00e1 Die B 110
Shrinkage (in/in) linear ASTM D2566 @ 1 depth 0.0025
Note: Reported physical properties are based on a 7 day room temperature cure.
HANDLING PROPERTIES Part A Part B
Mix Ratio by weight 100 10
Mix Ratio by volume 100 12
Specific Gravity @ 77 F (25 C) 1.22 1.00
Color Off White Blue
Viscosity (cps) @ 77 F (25 C) Brookfield 61,000 60
Mixed Viscosity (cps) @ 77 F (25 C) Brookfield 31,000
Work Time, 100g mass @ 77 F (25 C) 30 40 minutes
Gel Time 50 60 minutes
Demold Time @ 77 F (25 C) 4 6 hours
SILICONE CASTING RUBBERS
Dedicated to QUALITY, SERVICE, SAFETY, and INNOVATION
An ISO-9001 Certified company
TC-5024 A/B Page 2 of 2 Date: 07/18/2022
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.”
MIXING:
TC-5024 A/B is processed by adding curing agent “B” at a ratio of 10 parts by weight to 100 parts by weight of “A”. TC-5024
“B” side is tinted blue so that when mixing the “A” and “B” sides together, the colorant in the “B” side will provide a visible
means of insuring that a uniform mix is acquired. Mix for 2 to 3 minutes in a clean container, then transfer material to another
clean container and mix for another 2 to 3 minutes.
INHIBITION:
New molds made with tin catalyzed silicones often have a tendency to inhibit the cure of softer elastomeric and aliphatic
urethanes (Water Clear Series) that are cast against the silicone. Post curing a new mold at 150 F for 24 hours may reduce the
cure inhibition problem in most cases. It is also recommended that the mold surface be washed thoroughly with soap and warm
water then dried before use.
STORAGE:
Store ambient temperatures, 65-80 F (18-27 C). Unopened containers will have a shelf life of 12 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. 3.2 oz. 51
Gallon Kits 8 lbs. 13 oz. 205
5-Gallon Kits 40 lbs. 4 lbs. 1,021
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. Solvent 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 Methanol (by product), which is known to the State of
California to cause birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.
Silicone Handling Guide
by | Sep 27, 2025
TC-5015 A/B Page 1 of 2 Date: 05/25/2022
For more information call BJB Enterprises, Inc. (714) 734-8450 Fax (714) 734-8929
www.bjbenterprises.com
TC-5015 A/B
TRANSLUCENT SILICONE RUBBER
TC-5015 A/B is a room temperature, addition/platinum curing silicone rubber designed for making molds and parts. When
used to make molds, the TC-5015 A/B is translucent enough to see through when casting into the mold cavity. This aids in
developing void free surfaces on the casting. TC-5015 A/B is also commonly used to make ink stamp pads as well as other
types of pressure pads.
PHYSICAL PROPERTIES TEST METHOD RESULTS
Hardness, Shore A ASTM D 2240-04e1 15 5
Density (g/cc) ASTM D 792-00 1.06
Cubic Inches per Pound N/A 26.2
Color/Appearance Visual Colorless/Translucent
Tensile Strength (psi) ASTM D 412-98a(2002)e1 320
Elongation (%) ASTM D 412-98a(2002)e1 350
Tear Strength (pli) ASTM D 624-00e1 Die B 60
Shrinkage (in/in) linear ASTM D2566 @ 1 depth Nil
HANDLING PROPERTIES Part A Part B
Mix Ratio by weight 100 10
Specific Gravity @ 77 F (25 C) 1.07 0.97
Color Colorless Colorless
Viscosity (cps) @ 77 F (25 C) Brookfield 31,000 80
Mixed Viscosity (cps) @ 77 F (25 C) Brookfield 15,000
Work Time, 100g mass @ 77 F (25 C) 25 minutes
Gel Time 30 minutes
Demold Time @ 77 F (25 C) 24 hours
Properties above are typical and not for specifications.
INHIBITION:
Certain materials will cause inhibition or neutralization of the curing agent. These materials include condensation/tin cured
based silicone, lacquer and enamel coatings, polyester-based products, copper or copper containing metals, some SLA resins,
and natural rubbers like latex. Inhibition may easily be determined by brushing a small quantity of TC-5030 A/B over a
localized area of the surface to be reproduced. If the TC-5015A/B is tacky or uncured after the cure time, then you know the
mold surface is acting as an inhibitor. Molds made from wood, plaster, steel, aluminum, or plastic should not cause inhibition
if they are clean. To insure against possible problems, it is advisable to spray a barrier film over any questionable surfaces.
This is the best way of treating clays and other surfaces that cause inhibition. Contact BJB for recommended products.
SILICONE CASTING RUBBERS
Dedicated to QUALITY, SERVICE, SAFETY, and INNOVATION
An ISO-9001 Certified company
TC-5015 A/B Page 2 of 2 Date: 05/25/2022
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.”
STORAGE:
Store ambient temperatures, 65-80 F (18-27 C). Unopened containers will have a shelf life of 12 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. 3.2 oz. 58
Gallon Kits 8 lbs. 13 oz. 231
5-Gallon Kits 40 lbs. 4 lbs. 1,153
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.
Silicone Handling Guide
by | Sep 27, 2025
TC-5015 A/B Page 1 of 2 Date: 05/25/2022
For more information call BJB Enterprises, Inc. (714) 734-8450 Fax (714) 734-8929
www.bjbenterprises.com
TC-5015 A/B
TRANSLUCENT SILICONE RUBBER
TC-5015 A/B is a room temperature, addition/platinum curing silicone rubber designed for making molds and parts. When
used to make molds, the TC-5015 A/B is translucent enough to see through when casting into the mold cavity. This aids in
developing void free surfaces on the casting. TC-5015 A/B is also commonly used to make ink stamp pads as well as other
types of pressure pads.
PHYSICAL PROPERTIES TEST METHOD RESULTS
Hardness, Shore A ASTM D 2240-04e1 15 5
Density (g/cc) ASTM D 792-00 1.06
Cubic Inches per Pound N/A 26.2
Color/Appearance Visual Colorless/Translucent
Tensile Strength (psi) ASTM D 412-98a(2002)e1 320
Elongation (%) ASTM D 412-98a(2002)e1 350
Tear Strength (pli) ASTM D 624-00e1 Die B 60
Shrinkage (in/in) linear ASTM D2566 @ 1 depth Nil
HANDLING PROPERTIES Part A Part B
Mix Ratio by weight 100 10
Specific Gravity @ 77 F (25 C) 1.07 0.97
Color Colorless Colorless
Viscosity (cps) @ 77 F (25 C) Brookfield 31,000 80
Mixed Viscosity (cps) @ 77 F (25 C) Brookfield 15,000
Work Time, 100g mass @ 77 F (25 C) 25 minutes
Gel Time 30 minutes
Demold Time @ 77 F (25 C) 24 hours
Properties above are typical and not for specifications.
INHIBITION:
Certain materials will cause inhibition or neutralization of the curing agent. These materials include condensation/tin cured
based silicone, lacquer and enamel coatings, polyester-based products, copper or copper containing metals, some SLA resins,
and natural rubbers like latex. Inhibition may easily be determined by brushing a small quantity of TC-5030 A/B over a
localized area of the surface to be reproduced. If the TC-5015A/B is tacky or uncured after the cure time, then you know the
mold surface is acting as an inhibitor. Molds made from wood, plaster, steel, aluminum, or plastic should not cause inhibition
if they are clean. To insure against possible problems, it is advisable to spray a barrier film over any questionable surfaces.
This is the best way of treating clays and other surfaces that cause inhibition. Contact BJB for recommended products.
SILICONE CASTING RUBBERS
Dedicated to QUALITY, SERVICE, SAFETY, and INNOVATION
An ISO-9001 Certified company
TC-5015 A/B Page 2 of 2 Date: 05/25/2022
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.”
STORAGE:
Store ambient temperatures, 65-80 F (18-27 C). Unopened containers will have a shelf life of 12 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. 3.2 oz. 58
Gallon Kits 8 lbs. 13 oz. 231
5-Gallon Kits 40 lbs. 4 lbs. 1,153
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.
Silicone Handling Guide
by | Sep 27, 2025
470 E. BONITA AVE. POMONA, CA 91767
PH (909) 625-0056 WWW.SILPAK.COM FX (909) 625-0082
URETHANE PLASTIC
Product Data Sheet
Urethane casting resins are two-component, low viscosity liquids that polymerize to a hard plastic part in
minutes to hours, depending on thickness. These quality-casting resins are used in art reproductions,
model kits, stage props, prototype pieces, tools, and for duplicating masters. Several different systems that
vary in Gel Time (Work Time), Color, Hardness and Strength are available.
Available Sizes: Qrt kits (4 lbs), Gallon kits (16 lbs), 5Gallon kits (80 lbs), Drum Kits (900 lbs) Drum kits.
*Made for Mass Castings with 1-4 hours Cure, depending on casting thickness; Thin Casting Not Recommended
Fillers and Pigments are available for customizing finish piece.
Urethane plastics should be painted with an oil-base primer and cleaned with a solvent or hot soapy
water solution before a final finish is applied.
Optically Clear Casting Resins with UV stability are available RU-500 Series.
Uncured Urethane Components are sensitive to moisture (Part B) that can cause bubbles and foaming
in casted parts. UV light can discolor cured urethane plastic parts and should be painted for color
stability.
ADDITIVES:
Pigments: Red, Yellow, Blue, Black, Brown, Flesh Tone, White
Translucent Dyes: Red, Yellow, Blue, Black
Specialty Pigment Powders: Glow Dust, Bright Shade Powder/ Green-Violet-Red-Yellow-Orange
Metal Powders: Bronze CB-21, Brass CG-10, Copper CC-11, Iron CI-30, White Metal CS-73
Fillers: Prolite FR 50, Limestone CC-200, Hollow Glass HGF-100, Glass Beads GF-3000,
Thermo-Conductive GAP-25, Marble Powder MP-200, Porcelain PP-300
THE INFORMATION AND DATA CONTAINED HEREIN ARE BASED ON INFORMATION WE BELIEVE RELIABLE. EACH
USER OF THE MATERIAL SHOULD THOROUGHLY TEST ANY APPLICATION AND INDEPENDENTLY CONCLUDE
SATISFACTORY PERFORMANCE BEFORE COMMERCIALIZING. SUGGESTIONS OF USES SHOULD NOT BE TAKEN AS
INDUCEMENTS TO INFRINGE ON ANY PARTICULAR PATENT.
Color Tensile Gel
Time
Viscosity
A/B
Hardness
SILTEC Translucent 2565 3min 50 / 480 55 D
SILWHITE White 2389 3min 150 / 250 65 D
SILTOOL Tan 2050 3min 150 / 250 65 D
SILCAST II White 2560 3min 75 / 100 65 D
SILPLASTIC Tan 2450 5min 125 / 150 65 D
QUICKCAST White 2390 3min 50 / 100 70 D
THERMOCAST II Tan 6100 3min 200 / 250 70 D
FASTKAST 75 White 4990 2min 150 / 225 75 D
HARDCAST Tan 2425 3min 150 / 225 75 D
SLOWCAST* Translucent/White 4190 9min 50 / 400 75 D
by | Sep 27, 2025
!
MOLD RELEASE 4
ee
{. S83 TM
: = @ _ _________ NSF Registered; H2 Rated (Lubri
sf 9 y NX with no contact) (Registration # 118
thle DIIRpAS: Maximum operational temperature:
FE a a PURE aa sre 550 F (287 C)
Baeer, on | 2.0%
s pep or = . = 2% Silicone
eit) ae
ho tie = san Meets FDA CFR 21
-Desprendimiento aH
te 2 20%
| Uso General ae / Stare) his peed ree
agin a) jy RO Heaith (2) Flammability (2) * Rea
i MUM mh it are –
SS ee
= 1202-3405 e Meets FDA regulations
<= ee 2% silicone
: Non-staining, non-corrosive
Works from 40 F to 550 F
~ e Multi-purpose
: <_S | PRESERVE. PROTECT. PREVENT.
Sprayon MR 302 General Purpose Release Agent contains a light duty silicone that is ideal
for cold molds. A multi-purpose mold release that does not contain chlorofluorocarbons.
Recommended for use on acrylics, cellulosics, A.B.S. resins, polystryrene, polyesters, wax and
jalan hag DA ron Tate! Dio o ole Wat -Vat tates a =Wnntet al Bot faacl
by | Sep 27, 2025
SILPAK R-1328
High Strength, General Purpose, Tin RTV Silicone System
R-1328 is a 25 Shore A, tin Base (condensation cure), two-component, room temperature cure (RTV) rubber
designed primarily as general purpose, high-strength rubber for making molds and flexible rubber parts. Use molds
to cast polyester, urethane, epoxy, low melt metal (350 F), thermoplastics (polyvinyl), wax, soap, plaster, and any
material where a release free casting is required.
Features
e Excellent physical properties Low viscosity for easy pouring
* High tear resistance Additional Activators available for faster cure
e Long working life finished molds and brush on applications.
Applications
Use molds to cast polyester, urethane, epoxy, low melt metal (350 F), thermoplastics (polyvinyl), wax, soap,
plaster, and any material where a release free casting is required.
e Production molds e Production parts
Physical and Handling Properties
Property Value
Color White Base / Green Activator
Mix Ratio, by weight 100 Base:10 Activator
Initial Viscosity, Part A, cP 30,000
Initial Viscosity, Part B, cP 50
Initial Mixed Viscosity, at 77 F, cP 20,000
Pot Life, min 90
Demold Time, hr 16
Specific Gravity 1.18
Tensile Strength, psi 360
Elongation, % 500
Tear Resistance, pli 135
Values listed above are typical and not intended for use in specifications.
Silpak is a division of Polytek Development Corp. – www.silpak.com – 800.858.5990 – 55 Hilton Street, Easton, PA 18042
by | Sep 27, 2025
TC-5002 A/B Page 1 of 2 Date: 02/02/2023
For more information call BJB Enterprises, Inc. (714) 734-8450 Fax (714) 734-8929
www.bjbenterprises.com
SC-5002
SILICONE THINNER
This thinner was developed to help reduce the mixed viscosity of BJB s RTV silicones. The reduced viscosity is advantageous
when pouring into highly detailed areas.
APPLICATION:
SC-5002 can be added to any of BJB s RTV silicones. We would not recommend the addition of more than 20% of SC-5002
to the total mix of the A & B silicone system. Higher levels can significantly reduce the physical properties of the silicone.
The addition of SC-5002 will also lower the shore hardness of the silicone and lengthen the work life and ultimate cure time.
TYPICAL PHYSICAL PROPERTIES
TC-5050 A/B
without SC-5002
TC-5050 A/B
with 5% SC-5002
TC-5050 A/B
with 10% SC-5002
TC-5050 A/B
with 20% SC-5002
Hardness, Shore A 50 A 40 A 37 A 36 A
Hardness, Shore 00 — — — —
Viscosity (cps) 90,000 65,000 50,000 32,000
TC-5024 A/B
without SC-5002
TC-5024 A/B
with 5% SC-5002
TC-5024 A/B
with 10% SC-5002
TC-5024 A/B
with 20% SC-5002
Hardness, Shore A 25 A 14 A 10 A —
Hardness, Shore 00 — 70 00 60 00 52 00
Viscosity (cps) 31,000 23,000 17,000 11,000
HANDLING PROPERTIES
Specific Gravity @ 77 F (25 C) 0.97
Color Clear
STORAGE:
Store ambient temperatures, 65-80 F (18-27 C). Unopened containers will have a shelf life of 12 months from date of
shipment when properly stored at recommended temperatures. Purge opened containers with dry nitrogen before re-sealing.
PACKAGING
Quarts 2 lbs.
Gallons 8 lbs.
5-Gallon Kits 40 lbs.
SILICONE CASTING RUBBERS
Dedicated to QUALITY, SERVICE, SAFETY, and INNOVATION
An ISO-9001 Certified company
TC-5002 A/B Page 2 of 2 Date: 02/02/2023
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.”
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.
by | Sep 27, 2025
Liquid Rubber Urethane RTV
RU-480 A/B 80 A Shore is a liquid, two-component, Urethane Elastomer RTV that is easily processed. This
system provides a firm, semi-flexible, durable and abrasion resistant rubber compound. Used for a variety of
applications including molds, concrete texture stamps and form liners, and rubber parts. Molds are used to cast
concrete, wax, and plaster parts. Also makes molds that are compatible for casting Silicone Platinum RTV.
Features
Easy to Process with 2 to 1 Mix Ratio Dimensionally Stable Minimal Shrinkage
Excellent Strength Properties Abrasion resistant for long mold life
Applications
Molds are used to cast concrete, wax, and plaster parts. Also makes molds that are compatible for casting Silicone
Platinum RTV. Use for making molds or rubber parts. Molds are used to cast:
e Making Molds e Concrete Texture stamps and form liners
Rubber parts
Physical and Handling Properties
Property Typical Value
Cured Color Yellow/Translucent
Mix Ratio, by weight 2A1B
Initial Mixed Viscosity, at 77 F, cP 5,000
Shore Harness A80
Pour Time 20 min.
Demold Time at 73 F 16 hrs.
Specific Volume (in?/Ib) 26
Specific Gravity 1.07
Tensile Strength, psi 800
Elongation, % 550
Die C Tear Strength (pli) 175
Values listed above are typical and not intended for use in specifications.
Proper Use and Safety
Read all instructions and safety data sheets prior to use. Consult safety data sheets for all recommended safety
precautions.
Silpak is a division of Polytek Development Corp. – www.silpak.com – 800.858.5990 – 55 Hilton Street, Easton, PA 18042
by | Sep 27, 2025
SILPAK RU-448
Performance Polyurethane Rubber
RU-448 A/B is a 45 shore A hardness, polyurethane RTV elastomer that cures to a rubber material with excellent
tear strength and abrasion resistance. It has a simple 1:1 mix ratio and low viscosity for easy processing.
Features
Excellent tear resistance and elongation Rapid mold cycle
e Easy to process
Applications
Applications include the following or any application where a flexible rubber part is required.
Concrete texture and stamp pads e Concrete form liners
e Rubber molds and parts e Prototype rubber parts
Physical and Handling Properties
Property Value
Color Yellow
Mix Ratio, by weight 1A: 1B
Initial Mixed Viscosity, cP 3,000
Hardness, Shore A 45
Gel Time, min 30
Demold Time, hr 16
Specific Gravity 1.02
Tensile Strength, psi 650
Elongation, % 800
Tear Resistance, pli 90
Values listed above are typical and not intended for use in specifications.
Proper Use and Safety
Read all instructions and safety data sheets prior to use. Consult safety data sheets for all recommended safety
precautions.
Master Preparation
Polyurethane RTVs will adhere to most surfaces. A proper mold release must be used on all surfaces. Silpak ER
2300 is recommended. Wood, plaster, stone, pottery, masonry or any porous surface must be sealed with lacquer
or clear shellac prior to applying release. PartAll Film #10 or shellac is suitable for sulfur and water-based clays.
Allow 24 hours to dry before preparing master with mold release. Plaster masters can release air when pouring
larger molds due to some heat generated. Venting the base of your master by drilling several % holes will release
the air downward to avoid air entrapment in the mold cavity. Polyurethane RTV cures to a flexible rubber at the
cure time noted above.
Silpak is a division of Polytek Development Corp. – www.silpak.com – 800.858.5990 – 55 Hilton Street, Easton, PA 18042
by | Sep 27, 2025
470 E. BONITA AVE. POMONA, CA 91767
PH (909) 625-0056 WWW.SILPAK.COM FX (909) 625-0082
Rapid Curing Urethane Castable Rubbers
Product Data Sheet
Product Description and Applications
These are two-component, 100% solid Urethane RTV Elastomers that provide a rubber material with good strength properties.
Their simple 1 to 1 mix ratios, low viscosities and ability to cure in Tin or Platinum Silicone RTVs allow for easy processing.
These flexible Urethane RTVs are used in a variety of applications: prototype rubber parts and molds, or any application where a
flexible rubber part is required.
Unique Characteristics
Curable in Tin or Platinum Silicone RTV
Good Tear Resistance and Elongation
Rapid De-mold Times for Prototyping
Ability to INTER-MIX Systems for Custom Hardness/Durometer
RU-320 A/B RU-350 A/B RU-385 A/B
Color Off White Clear Amber Clear Amber
Mixed Viscosity (cps) 500 530 1,570
Mix Ratio 100 A: 100 B 100 A : 100 B 100 A : 100 B
Shore A Hardness 20 50 85
Tensile Strength (psi) 270 260 1105
Elongation % 800 230 270
Tear Resistance (pli) 60 55 180
Specific Gravity 1.02 1.05 1.05
Gel Time (min) 4-5 4-5 4-5
Demold Time (min) 90-120 60-90 60-90
*Full Cure within Days @ 77F or Post cured at 150F for 12-16 Hours
Preparation of Mold
Use a Silicone RTV Mold Tin or Platinum RTV works best with these systems since no mold release is needed when casting
into Silicone RTV. If using Latex, Urethane RTV rubber or any other type of mold, a proper mold release must be used MR150
or ER-2300 is recommended. Ensure that all surfaces are dry and free from moisture prior to casting to prevent material
contamination.
Mixing
Before mixing, ensure that material and molds are at proper working temperature above 65F. These systems are fast curing
and should be processed quickly. Before adding A to B, part B should be stirred or shaken thoroughly to ensure that any
separated material is remixed. Select a clean, dry plastic container for mixing. Avoid using wood or paper products, which could
cause cure problems. Weigh out the proper ratio of A to B and mix well, scraping sides and bottom of mixing container to ensure
a thorough mix. After mixing usually within 45-60 seconds immediately pour into mold.
Curing
Do not disturb the mold until part is ready to be de-molded. Prematurely demolding parts may cause deformation, especially in
thin areas. Preheating molds 100F will expedite cure, while low temperatures will slow curing time and extend the demold
time. To expedite a full cure, post cure parts at 150F for 12-16 hours. Note: Pressure casting applying positive pressure 40-60
psi will improve clarity and rubber performance.
1
2
Storage/Shelf Life
A and B components must be stored in their original, unopened containers at temperatures between 65F and 85F. Shelf life of
materials when kept in unopened sealed containers, at the recommended storage conditions, is 6 months. Containers should
not be opened until ready for use. Once containers are opened, material should be used in a short time period. Pre-test any
aged material before using.
Handling and Safety
Use proper equipment gloves, glasses and apron when using materials. Avoid direct contact with skin and eyes. If skin contact
occurs, clean area with waterless hand cleaner or isopropyl alcohol. For eye contact, flush eye with water for 15 minutes and
call physician. Use materials under adequate ventilation. *See SDS for further information.
ACCESSORIES
Colorants:
All pigments should be added to the “B” side only at 1-2%. Castable urethanes are affected by direct and indirect sunshine and
will discolor over time.
CU Pigment Red, Yellow, White, Blue, Black, Brown, Fleshtone
Bright Shade Powder Green, Orange, Red, Yellow, Pink Dry powdered pigments requiring thorough premixing
UD Dye Red, Yellow, Black, Blue Transparent coloring used in Clear and Transparent Urethane & Epoxy
THE INFORMATION AND DATA CONTAINED HEREIN ARE BASED ON INFORMATION WE BELIEVE RELIABLE. EACH USER OF THE
MATERIAL SHOULD THOROUGHLY TEST ANY APPLICATION AND INDEPENDENTLY CONCLUDE SATISFACTORY PERFORMANCE
BEFORE COMMERCIALIZING. SUGGESTIONS OF USES SHOULD NOT BE TAKEN AS INDUCEMENTS TO INFRINGE ON ANY
PARTICULAR PATENT.
