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Mountain Grout Ultra is a moderate-viscosity hydrophobic polyurethane formulation for sealing leaking cracks and joints where some movement is possible. When injected into wet cracks, it reacts with water to produce a closed-cell foam.
What it does
Ultra is used in water-related structures to form an inert, non-toxic permanent seal. Its cured elongation of 300% suits leaking cracks or joints where movement may occur, while the hydrophobic foam maintains its physical form through wet and dry cycles.
The system consists of Ultra base resin and MG Accelerator “B”. The accelerator allows an experienced installer to adjust the reaction profile according to job-site temperature and the amount of moisture encountered.
Numbers that matter
- 650 cps viscosity: Moderate-viscosity base resin that pumps as a single component after the accelerator has been added.
- 300% elongation: Supports use in leaking cracks and joints where some movement is possible.
- Expands up to 25 times: The reacting polyurethane foam can expand up to 25 times its initial volume.
- 224 kg/m³ cured density: Measured in accordance with ASTM D-1622.
- 300 psi tensile strength: Measured in accordance with ASTM D-638.
Adjusting the reaction time
At 25°C, adding MG Accelerator “B” at 1.25%—equivalent to 1/2 pint per five gallons—produces an expansion start time of about 50 seconds and completion in about five minutes after contact with water.
At 25°C, adding MG Accelerator “B” at 2.5%—equivalent to one pint per five gallons—produces an expansion start time of about 30 seconds and completion in about three minutes after contact with water.
Job-site conditions
- The reaction profile is affected by temperature and the amount of moisture encountered.
- MG Accelerator “B” is intended to be used by an experienced installer to adjust the reaction profile before pumping.
- The stated reaction times were determined at 25°C.
Frequently asked questions
What is Mountain Grout Ultra used for?
It is used to seal leaking cracks or joints where some movement is possible, including applications in water-related facilities, tunnels, dams, manholes, elevator pits and parking garages.
What happens when Ultra contacts water?
When injected into wet cracks, Ultra reacts with water and produces a closed-cell foam that can expand up to 25 times its initial volume.
Does the cured foam shrink during wet and dry cycles?
The hydrophobic foam maintains its physical form and is not subject to shrinkage caused by wet and dry cycles.
How is the reaction time controlled?
The reaction profile is adjusted before pumping by adding MG Accelerator “B” to the base resin. The result is affected by temperature and the amount of moisture encountered.
What is the cured elongation?
The cured material has 300% elongation when tested in accordance with ASTM D-638.
Uses and benefits
| Application | Why it fits |
|---|---|
| Water-related facilities and stormwater systems | Reacts with water to form a closed-cell hydrophobic polyurethane foam. |
| Waste treatment plants and manhole facilities | Cures to an inert, non-toxic permanent seal and is listed as having excellent resistance and durability. |
| Concrete dams, earthen dams and tunnels | Expands up to 25 times its initial volume and has 300% cured elongation. |
| Underground vaults and elevator pits | Designed for sealing leaking cracks or joints where some movement is possible. |
| Parking garages | Provides a hydrophobic foam that maintains its physical form through wet and dry cycles. |
How to adjust the reaction profile
- Select the accelerator level: Add MG Accelerator “B” to the Ultra base resin before pumping.
- For a slower reaction at 25°C: Use 1.25% accelerator, equivalent to 1/2 pint per five gallons. Expansion starts in about 50 seconds and is complete in about five minutes after contact with water.
- For a faster reaction at 25°C: Use 2.5% accelerator, equivalent to one pint per five gallons. Expansion starts in about 30 seconds and is complete in about three minutes after contact with water.
- Allow for site conditions: Temperature and the amount of moisture encountered affect the reaction profile.
Limitations and job-site conditions
- Reaction conditions: Reaction times vary with temperature and the amount of moisture encountered.
- Published timing: The stated start and completion times were determined at 25°C.
- Accelerator adjustment: MG Accelerator “B” is used by an experienced installer to manipulate the reaction profile according to job-site conditions.
Mountain Grout Ultra Physical Properties
| Property | Value |
|---|---|
| Product Type | Hydrophobic polyurethane formulation |
| Available Sizes | 4 kg, 20 kg |
| System Components | Ultra base resin with MG Accelerator "B" |
| Base Resin Viscosity | 650 cps |
| Accelerator Viscosity | 25 cps |
| Base Resin Specific Gravity | 1.07 |
| Accelerator Specific Gravity | 0.95 |
| Base Resin Colour | Pale yellow |
| Accelerator Colour | Clear |
| Base Resin Flash Point | >121°C |
| Accelerator Flash Point | 107°C |
| Cured Density | 224 kg/m³ |
| Cured Elongation | 300% |
| Cured Tensile Strength | 300 psi |
| Cured Toxicity | Non-toxic |
| Solids Content | 100% |
| VOC Content | No VOCs |
| Expansion | Up to 25 times initial volume |
| Foam Structure | Closed-cell foam when injected into wet cracks |
| ASTM D-1638 | Viscosity |
| ASTM D-1475 | Specific gravity |
| ASTM D-92 | Flash point |
| ASTM D-1622 | Cured density |
| ASTM D-638 | Elongation and tensile strength |
| Accelerator Ratio 1 | 1.25% (1/2 pint per five gallons) |
| Reaction Time At 1.25% | Expansion starts in about 50 seconds and is complete in about 5 minutes after encountering water at 25°C |
| Accelerator Ratio 2 | 2.5% (1 pint per five gallons) |
| Reaction Time At 2.5% | Expansion starts at 30 seconds and is complete at about 3 minutes after encountering water at 25°C |