DOWSIL 790
Harmonization Code : 2901.10.00.00 | Acyclic hydrocarbons; Saturated
Main features
- +100/-50% Joint Movement
- Ultra-Low-Modulus Cured Seal
- Non-Sag 10-20-Minute Tooling
Product Description
DOWSIL 790 Silicone Building Sealant provides one-part, neutral-cure, ultra-low-modulus sealing for new and remedial construction joints. Its non-sag formulation provides a 10-20 minute working time and a one-hour tack-free time at 50% relative humidity, supporting vertical and overhead joint installation. After seven days at 25 deg C and 50% relative humidity, the sealant has Shore A 15 hardness and ASTM C719 +100/-50% extension/compression capability for high-movement joints. Applications include expansion and control joints, precast concrete panel joints, EIFS joints, curtain-wall and mullion joints, and stone-paver joints. The product is not intended for structural applications.
Key features
- Ultra-low-modulus cure: Shore A 15 hardness supports high-movement construction joints.
- Class 100/50 movement: ASTM C719 extension/compression capability is +100/-50%.
- Non-sag application: A 10-20 minute working time supports tooling before cure.
Applications
Expansion, control, precast-panel, EIFS, curtain-wall, mullion and stone-paver movement joints.
Technical Specifications
Physical Properties
Mechanical Properties
Additional Information
As-supplied / before-processing properties
Typical application and cure-development properties. Values are not specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Tack-free time | 1 | hr | ASTM C679; 50% relative humidity |
| Curing time | 7-14 | days | At 25 deg C and 50% RH; 3/8 in depth |
| Full adhesion | 14-21 | days | Cured joint |
| Flow, sag or slump | None | ASTM D2202 | |
| Working time | 10-20 | min | CTM 98 |
| VOC content, maximum | 23 | g/L | EPA Method 24 |
After-processing / final-state properties
Typical properties after seven days at 25 deg C and 50% relative humidity.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Durometer hardness | 15 | Shore A | ASTM C661 |
| Tensile strength, maximum | 100 | psi | ASTM D412 |
| Peel strength | 25 | lb/in | ASTM C794 |
| Tensile at 25% extension | 15 | psi | ASTM C1135 |
| Tensile at 50% extension | 20 | psi | ASTM C1135 |
| Joint movement capability | +100/-50 | % | ASTM C719; extension/compression |
| Staining | None | ASTM C1248; various substrates |
