PSI-901 Caulk is a one-part, non-sag, low modulus polyurethane sealant specifically developed for sealing dynamically moving joints between materials of dissimilar porosities, coefficients of expansion and surface textures. It cures to a flexible rubber with extraordinary adhesion and cohesion, capable of accommodating joint movement of +100% and –50% of the original joint width. In sharp contrast to other commercial urethane sealants, PSI-901’s unique curing chemistry, involving atmospheric oxygen, permits the sealant to cure readily under all climatic conditions independent of relative humidity, making it the sealant of choice in dry climates and during dry winter weather everywhere. Because PSI-901 contains no free isocyanates, it presents none of the health and disposal hazards usually associated with materials containing isocyanates. This sealant is resistant to mild chemicals and sol-vents. However, testing is recommended to determine its suitability to a particular application. It is virtually unaffected by long term exposure to rain, snow, sleet, ice, sunlight, ultraviolet radiation, atmospheric pollution, etc. This sealant formulation will not cold slip.*
BASIC USES
PSI-901 is ideal for sealant expansion and control joints in pre-cast concrete, tilt-up, poured-in-place concrete, metal curtain walls, perimeter caulking (doors, windows, panels, bedding, steps and risers), and glazing.
*Cold slip is the tendency of certain polyurethane sealants to slip out of a joint in mass when the temperature of the sealant is under 40°F when applied and the air temperature is also under 40°F.
APPLICATION LIMITATIONS
(a) PSI-901 should not be used for structural or butt glazing.
(b) PSI-901 is not recommended for use in water immersion applications.
(c) PSI-901 should not be used in joints less than ¼” in width or depth.
(d) PSI-901 should not be used with certain architectural coatings without prior testing.
(e) PSI-901 should not be used on absorptive surfaces such as marble, limestone, or granite without prior testing for discoloration or staining.
(f) PSI-901 should not be used in areas where odor is objectionable.
COLORS
White, Gray, Limestone, Bronze, Black and Tan.
PACKAGING
PSI-901 is available in 10.3 fl. Oz. (305 ml) cartridges; 12 cartridges per carton. 2 gallon pails, 5 gallon pails and drums are available on special order.
APPLICABLE STANDARDS
PSI-901 meets or exceeds the requirements of Federal Specification TT-S00230C Type II, Class A; ASTM C920-87 Type S, Grade NS, Class 25; Use NI, G, M, A, and O; AAMA 802.3 and 805.2; CAN/CGSB 19.13-M87. Authorized by USDA for use in federally inspected meat and poultry plants.
TECHNICAL DATA: Refer to table below for typical properties*
*For information only – not for specification purposes.
PERFORMANCE PROPERTIES | RESULTS | TEST METHOD |
Tack-Free Time, bulk, hours : | 3-1/2 + ½ | ASTM C679 |
Tack-Free Time, cartridges, hours: | 4,500 lb/square inch | ASTM C679 |
Application Rate, grams/min.(1/8” orifice, 30 psi, 75°F): | > 65 | TT-S00230C |
Sag/Slump, inches: | nil | ASTM C639 |
Adhesion-in-Peel, lb/in Aluminum, glass & vinyl: | 25 + 5 | ASTM D661 |
Tensile Strength, psi: | 130 + 10 | ASTM D412 |
Ultimate Elongation,%: | 450 + 10 | ASTM D412 |
Hardness, Shore A: | 25 + 5 | ASTM C 661 |
Staining: | None | ASTM C510 |
Weight Loss, %(max) | 5 | ASTM C792 |
& Cracking & Chaulking after Heat Aging: | None | |
Durability (Bond & Cohesion) on mortar, aluminum, glass Joint Movement, %: | +25 | ASTM C719 |
Classification: | Type II, Class A | TT-S-00227E |
Joint Movement, %: | +25 | ASTM C920-87 |
Classification: | Class 25 | |
Service Temperature, cured bead, F: | -80 to 160 | PSI 5406 |
VOC Content, lb/gl: | 0.3 | |
Specific Gravity: | 1.6 | |
INSTALLATION
Joint Design: The width of the bead should be a minimum of 4 times the calculated movement. The width or depth of the joint should not be less than l/4”. In joints up to ½” wide, the depth of the sealant should be equal to the width. In joints wider than ½”, the depth should be maintained at ½”. For butt joints, see PSI’s Joint Design Chart for recommended joint designs for specific building materials. Lap shear joints should have a width of at least twice the anticipated movement. Surface Preparation: Joints to receive sealant must be sound, smooth, uniform in dimensions and free from defects and foreign materials. They must also be clean, dry, free of frost and all contaminants, such as curing compounds, sealers (waterproofing), coatings, etc. To test adhesion, apply a sealant bead to each different substrate and allow to cure thoroughly, then pull one end of the bead to test adhesive strength.
Primer: PSI-901 has excellent adhesion to most common substrates such as glass, ceramic, aluminum, steel, PVC, concrete and wood. However, some materials may require priming in order to gain optimum adhesion. PSI-590 is recommended for non-porous surfaces such as plastics. For porous surfaces, PSI-67, a two-part epoxy primer, is recommended. If a one-part primer is required, PSI-591 is recommended.
Primer should be applied to a clean, dry surface prior to the installation of backer rod, bond breaker tape, and sealant. Primer must be kept within the confines of the joint to preclude possible staining.
Back-Up Material: The purpose of back-up material is to regulate the depth of the joint, to provide a surface against which the sealant is compressed when tooled, thus promoting better adhesion to the side walls, and to provide a non-adhering back surface, precluding the possibility of a three-sided joint. Where back-up material is not necessary or where a type is used that does not have release properties, a bond breaker tape should be used.
Closed cell polyethylene foam back-up material is recommended. It should not be punctured, twisted or excessively stretched during installation, nor should it be compressed more than 50% of its original diameter. Open cell backer rod is compatible with all PSI sealants as long as it remains dry.
Tooling: In vertical and horizontal joints, tooling is absolutely necessary to aid in adhesion, eliminate air bubbles, and give a highly desirable concave appearance.
Cleaning: Immediately remove all excess sealant and smears adjacent to joints with xylol as work progresses. For equipment clean up, use solvent equivalent to xylol or toluol. Consult manufacturer’s MSDS for safety precautions when using these solvents.
Shelf Life: Twelve months when stored in original, unopened container in a dry area at temperatures below 80°F.
Health Precautions: Use only with adequate ventilation. Keep away from heat and flame. Do not take internally. Avoid eye and skin contact. KEEP OUT OF REACH OF CHILDREN.
For additional health and safety information, consult a Material Safety Data Sheet.
MAINTENANCE
If the sealant is damaged and the bond is intact, cut out the damaged area and re-caulk. No primer is required. If the bond has been affected, remove the sealant, clean and prepare the joint in accordance with the instructions under “Surface Preparation” and re-caulk.
TECHNICAL SERVICES
PSI provides field service, specification assistance, performance data and use evaluations.
Adhesion Testing – By PSI: The program is intended to eliminate potential field application problems, by pre-testing the adhesion of PSI’s construction sealants on samples of building materials submitted by the customer. The tests will aid in determining the proper surface preparation method, effective solvents for cleaning and whether priming is necessary to achieve optimum adhesion. Following this procedure will remove many of the variables that affect field success.
Test samples should be identified as to manufacturer, origin, designed use, building project, person and firm originating the request.
Appropriate sketches of drawings showing the intended use can be helpful. They should be sent to the attention of PSI’s Technical Director.
Jobsite Testing of Substrates: A field test can be performed by applying several feet of the sealant to a representative joint and letting it reach full cure. Make a cut in the cured sealant across the joint the entire depth of the sealant. Make two vertical cuts several inches long, paralleling the sides of the joint as closely as possible and extending down from the cros cut. Grasp the free length of sealant and pull at a 90° angle to determine if a good bond has developed. With good adhesion, the sealant will usually tear cohesively or be difficult to remove from the surface.
WARRANTY
All recommendations, statements and technical data contained herein are based on tests we believe to be reliable and correct, but accuracy and completeness of said tests are not guaranteed and are not to be construed as a warranty, either expressed or implied. User shall rely on his own information and tests to determine the suitability of the product for intended use, and user assumes all risk and liability resulting from the use of this product.
Manufacturer’s sole responsibility shall be to replace that portion of the product of the manufacturer which proves to be defective. Manufacturer shall not be liable to the buyer or any third party for injury, loss or damage directly or indirectly resulting from use of, or inability to use the product.
Recommendations or statements other than those contained in a written agreement signed by an officer of the manufacturer shall not be binding upon the manufacturer.
