Technical Specification · Free Download
Polyurethane Construction Adhesive Technical Material Specification
Comprehensive technical specification for polyurethane construction adhesive used in Canadian fabrication, woodworking, and machining operations. Covers properties, sizing, machinability, defects, and handling guidelines.
Category
Adhesives & Sealants
Industry
Fabrication & Woodworking
Standard
ASTM D638 / D1002 / D903
Version
1.0 | 2026-06-06
Material Overview & Common Uses
Polyurethane construction adhesive is a high-strength, moisture-curing elastomeric adhesive widely used in Canadian industrial fabrication, woodworking, and machining environments. It bonds a broad range of substrates including wood, metal, concrete, stone, rigid foams, and many plastics without the need for primers or surface activators. Common applications include structural panel lamination, subfloor and underlayment bonding, countertop and backsplash installation, trim and molding attachment, metal-to-wood framing, and composite panel assembly. Its gap-filling properties and flexibility make it ideal for uneven surfaces and dynamic load conditions. In Canadian shops, it is often specified for cold-weather applications due to its ability to cure at temperatures as low as -10°C (14°F) and its resistance to freeze-thaw cycling once cured.
Core Technical Properties & Sizing
| Property / Parameter | Specification / Value |
|---|---|
| Chemical Family | One-component moisture-curing polyurethane prepolymer. |
| Viscosity | Thixotropic paste, typically 200,000–400,000 cP at 25°C (Brookfield). |
| Density | 1.10–1.25 g/cm³ (9.2–10.4 lb/gal). |
| Solids Content | 100% (solvent-free, zero VOC). |
| Open Time | 10–20 minutes at 23°C/50% RH; extends to 30+ minutes at lower temperatures. |
| Fixture Time | 30–60 minutes at 23°C/50% RH (light clamping recommended). |
| Full Cure Time | 24–48 hours at 23°C/50% RH (thicker beads may require 72 hours). |
| Service Temperature Range | -40°C to +90°C (-40°F to +194°F). |
| Tensile Strength (ASTM D638) | 3.5–5.0 MPa (500–725 psi). |
| Shear Strength (ASTM D1002 on aluminum) | 2.0–3.5 MPa (290–510 psi). |
| Peel Strength (ASTM D903 on wood) | 3.0–5.0 N/mm (17–28 pli). |
| Elongation at Break | 200–400%. |
| Hardness (Shore A) | 50–70. |
| Thermal Conductivity | 0.15–0.25 W/m·K. |
| Electrical Insulation | Dielectric strength > 10 kV/mm. |
| Standard Packaging | 310 mL cartridges (standard caulk tube), 600 mL sausage packs, 20 L pails, 200 L drums. |
| Cartridge Dimensions (310 mL) | 51 mm diameter × 215 mm length (nominal). |
| Sausage Pack Dimensions (600 mL) | 48 mm diameter × 300 mm length (nominal). |
| Shelf Life | 12 months from date of manufacture when stored unopened at 15–25°C (59–77°F). |
| Storage Temperature Range | 5–30°C (41–86°F); do not freeze. |
| Canadian Stock Sizes | 310 mL cartridges (24 per case), 600 mL sausages (12 per case), 20 L pails (1 per case). |
Machinability, Tooling & Feeds
Polyurethane construction adhesive is not machined in the traditional sense, but its application and removal require specific tooling and techniques.
| Parameter / Aspect | Recommendation / Guideline |
|---|---|
| Application (Cartridges) | Standard caulking gun (manual or pneumatic) with a 1/8" to 1/4" bead tip. |
| Application (Sausage Packs) | Sausage gun with a plunger. |
| Application (Pails) | Notched trowel (1/8" to 1/4" V-notch) for spread applications. |
| Cleanup (Uncured) | Acetone, xylene, or a commercial polyurethane adhesive remover. Do not use water as it accelerates curing. |
| Removal (Cured) | Mechanical removal via sanding (80–120 grit), grinding, or cutting with a sharp utility knife or oscillating multi-tool. |
| Sanding Specifications | Use open-coat aluminum oxide or zirconia alumina belts (80–120 grit) at 1500–2000 SFPM. |
| Machining Bonded Assemblies | Standard woodworking and metalworking feeds/speeds apply. Adhesive layer may cause rapid dulling of carbide tooling (reduce feed by 10–15% and increase tool change frequency). |
| Thermal Limit | Avoid overheating the adhesive (above 150°C) as it may degrade and produce isocyanate fumes. |
Common Defects & Quality Control
| Defect / Condition | Cause / Description | Corrective Action / QC Check |
|---|---|---|
| Skin formation | Moisture ingress in cartridge nozzle or on surface of pails. | Discard the first 1–2 cm of bead or skim the top layer. |
| Stringing / cobwebbing | Adhesive is too cold (below 10°C). | Warm cartridges to 20–25°C before use. |
| Poor adhesion | Contaminated or damp substrates (oil, dust, frost). | Ensure surfaces are clean, dry, and free of contaminants. |
| Foaming / bubbling | Excessive moisture or high humidity during cure. | Control ambient RH below 70%; avoid application on wet surfaces. |
| Incomplete cure | Thick beads (over 6 mm). | Limit bead thickness to 6 mm or use multiple passes. |
| Cracking / embrittlement | Extreme cold or UV exposure. | Use a UV-resistant grade for exterior applications. |
| QC Check (Viscosity) | Verify thixotropic paste consistency. | Ensure within spec range. |
| QC Check (Open Time) | 10–20 minutes at 23°C/50% RH. | Verify per lot upon receipt. |
| QC Check (Shear Strength) | Minimum 2.0 MPa on aluminum. | Perform ASTM D1002 test. |
| QC Check (Peel Test) | 90° peel on wood-to-wood bond. | Target > 3.0 N/mm (ASTM D903). |
| Incoming Inspection | Check cartridge integrity (no dents, leaks, swollen ends), lot number, and manufacture date. | Reject any material beyond 12 months from manufacture date or showing signs of separation/skinning. |
Storage, Handling & Racking Guidelines
| Parameter | Guideline |
|---|---|
| Storage Temperature | Cool, dry, well-ventilated area at 15–25°C (59–77°F). |
| Temperature Limits | Do not store above 30°C (86°F) or below 5°C (41°F). |
| Environmental Control | Avoid direct sunlight and UV exposure. Keep containers tightly sealed. |
| Orientation (Cartridges/Sausages) | Store horizontally in a rack to prevent nozzle clogging and skin formation. |
| Orientation (Pails) | Store upright with lids fully seated. |
| Stacking Limit | Do not stack pails more than two high. |
| Inventory Rotation | Use first-in-first-out (FIFO). Label each container with receipt date and expected expiry. |
| Shelf Life | 12 months from manufacture date when stored properly. |
| Winter Thawing Procedure | Allow frozen adhesive to thaw at 20–25°C for 24 hours before use. Do not use heat guns or microwaves. |
| Disposal (Uncured) | Hazardous waste (contains isocyanates). |
| Disposal (Cured) | Non-hazardous; can be disposed of in regular waste. |
| PPE Requirements | Always wear nitrile gloves and safety glasses. Ensure local exhaust ventilation in confined spaces. |
| Bulk Storage | Consider climate-controlled rooms with temperature monitoring for large-volume users. |