HCT Finishing Rinse — Hydroxylating Conversion Treatment for Carbonate Stone Protection
PROSOCO Conservare HCT Finishing Rinse is a two-component, waterborne finishing treatment designed to complete the chemical reaction initiated by Conservare HCT on deteriorating carbonate building stones. It forms a well-adhered, hydroxylated conversion layer on carbonate mineral grains, protecting and strengthening marble, limestone, dolomite, and travertine against the effects of acid rain, air pollution, and normal weathering. This product is intended for professional use and is applied as the second step following Conservare HCT for best performance results.
Unlike film-forming sealers, HCT Finishing Rinse does not create a surface coating — it reacts chemically with carbonate minerals to produce a microscopic crystalline layer that preserves natural water vapor permeability and resists bio-deterioration and acid dissolution. The low-viscosity, waterborne formulation contains no organic solvents or polymers, making it odorless and safe for job site use without special handling precautions.
Technical Specifications
| Specification | Details |
|---|---|
| Application Type | Hydroxylating conversion treatment for marbles & limestones |
| Form | Clear, colorless liquid; some clouding is normal |
| Components | Two-component, waterborne treatment (Step 2 — follows Conservare HCT) |
| pH | 12.4 |
| Specific Gravity | 1.001 |
| Weight per Gallon | 8.35 lbs |
| Freeze Point | Non-applicable (per page); 32°F / 0°C (per PDS) |
| Shelf Life | 1 year in tightly sealed, unopened container |
| VOC Content | Non-applicable; compliant with all national, state, and district VOC regulations |
| Flash Point | Non-applicable |
| Total Solids | Non-applicable |
| Coverage Rate | 50–80 sq ft/gal (see Product Data Sheet for substrate-specific variations) |
| Available Sizes | 5-gal |
| Suitable Substrates | Marble, limestone, dolomite, travertine |
| Film Formation | Does not form a film |
| Water Vapor Permeability | Treated surfaces retain natural water vapor permeability |
| Penetration | Low viscosity, deep penetration |
| Acid Rain Resistance | Dramatically reduces dissolution of carbonate stones in acid rain |
| Product Code | 42042 |
Key Features & Benefits
Dramatically Reduces Acid Rain Dissolution
The hydroxylated conversion layer formed by HCT Finishing Rinse is resistant to dissolution in acid rain, dramatically reducing the vulnerability of treated carbonate stones to acid attack. For contractors working on building exteriors exposed to urban pollution or acid precipitation, this provides a meaningful extension of stone service life.
Microscopic Crystalline Strengthening Layer
HCT Finishing Rinse completes a chemical reaction that produces a microscopic crystalline layer within the stone matrix, strengthening sugaring marble and deteriorating limestone without altering surface appearance. This is particularly valuable for restoration work on historically significant or high-value stone facades where structural integrity has been compromised.
Low Viscosity for Deep Penetration
The low-viscosity, waterborne formula penetrates deeply into the stone rather than concentrating at the surface, reducing the potential for delamination or flaking at the treated zone. Deep penetration ensures the conversion layer forms throughout the deteriorated material rather than just at the outer skin.
No Film Formation — Preserves Breathability
HCT Finishing Rinse does not form a surface film, so treated stones retain their natural water vapor permeability. Contractors can apply this treatment without trapping moisture behind a coating layer, which is critical for the long-term health of historic masonry and exterior stone assemblies.
Resistant to Bio-Deterioration
The conversion layer is resistant to bio-deterioration and reduces recurrence of biological soiling on carbonate surfaces. This translates to reduced maintenance frequency for building owners and longer intervals between cleaning cycles.
No Gloss, No Yellowing — UV Stable
HCT Finishing Rinse produces no gloss and does not yellow over time, remaining UV stable after treatment. Contractors can apply it to visible architectural stone without altering the aesthetic appearance expected by the client.
No Organic Solvents or Polymers
The odorless, waterborne formulation requires no special precautions for handling or clean-up and is compliant with all national, state, and district VOC regulations. This simplifies job site logistics and reduces regulatory burden for contractors operating across multiple jurisdictions.
Compatible with Conservare Consolidation Treatments
HCT Finishing Rinse is compatible with PROSOCO's Conservare OH100 and H100 Consolidation Treatments, allowing it to be incorporated into a broader stone preservation and consolidation protocol without compatibility concerns.
Common Applications
Acid Rain Protection on Exterior Stone Facades
Apply HCT Finishing Rinse as the second step of the two-step HCT system on exterior marble and limestone facades exposed to acid rain and air pollution to dramatically reduce surface dissolution and weathering.
Strengthening Sugaring or Deteriorating Marble
Use on marble surfaces exhibiting sugaring or granular disintegration to produce a microscopic crystalline layer that stabilizes and strengthens the deteriorated stone matrix.
Limestone and Travertine Preservation
Apply to deteriorating limestone and travertine building elements to reduce vulnerability to acid attack and extend the service life of the stone.
Historic and Architectural Stone Restoration
Incorporate into restoration projects involving carbonate stone — including dolomite, marble, limestone, and travertine — where preserving original material and appearance is required. Treatment should proceed after removal of deteriorated mortar joints and before installation of replacement mortars.
Biological Soiling Reduction on Carbonate Surfaces
The conversion layer reduces recurrence of biological soiling, making HCT Finishing Rinse suitable for stone surfaces in humid or shaded environments prone to algae, moss, or biological growth.
Compatible Materials
- Marble
- Limestone
- Dolomite
- Travertine
- Aged concrete or concrete with a predominance of carbonate aggregate (always test first)
Product Documents
Application Instructions
Surface Preparation
- Whenever possible, apply before installing new window glazing, paint finishes, or surface fixtures.
- Protect non-masonry and non-carbonate surfaces from contact with the product to minimize staining or discoloration.
- Avoid wind drift; protect and/or divert pedestrian and auto traffic.
- Remove all loose surface debris, crusts, paint coatings, bird droppings, or other contaminants from the dry stone.
- If additional surface cleaning is necessary, contact PROSOCO for cleaning recommendations. Previous treatments may adversely affect HCT treatment.
- Remove deteriorated mortar joints before treatment; install replacement mortars after HCT treatment is complete.
- Surface must be clean, dry, and absorbent to ensure deep penetration and reaction.
Temperature and Weather Conditions
- Best results are achieved when air and surface temperatures are between 50–90°F (10–32°C).
- Do not apply to wet surfaces, during rain, or when there is a chance of rain.
Equipment
- Preferred application method is low-pressure spray using corrosion-resistant sprayers to avoid discoloration.
- Do not atomize or vaporize the material.
- Adjust spray pattern to produce a saturating, low-pressure, wet spray.
Dilution and Use
- Use as packaged. Do not dilute or alter. Do not mix with other chemicals.
- Always test before full application for suitability and desired results. Let test area dry thoroughly before inspection.
- Apply HCT Finishing Rinse following Conservare HCT application as the second step of the two-step system.
Storage and Handling
- Keep from freezing. Store in a cool, dry place at 45–100°F (7–38°C).
- Always seal container tightly after dispensing.
- Do not double-stack pallets.
- Dispose of unused product and container in accordance with local, state, and federal regulations.
- Published shelf life assumes upright storage of factory-sealed containers in a dry place.
Safety Data Summary
Hazard Information
- Not a dangerous substance or mixture according to the Globally Harmonized System (GHS)
- May cause eye irritation
- Inhalation is not an expected route of exposure
- Contains water (60–100%) and calcium magnesium hydroxide (0.1–1%)
- Incompatible with strong acids
- Prevent product from entering drains
Personal Protective Equipment
- Safety glasses with side shields (or goggles)
- Protective nitrile rubber gloves
- NIOSH/MSHA approved respiratory protection if exposure limits are exceeded or irritation is experienced
Safe Handling
- Avoid contact with skin, eyes, or clothing
- Keep containers tightly closed in a dry, cool, and well-ventilated place
- Keep out of reach of children
- For eye contact: rinse immediately with plenty of water, including under the eyelids, for at least 15 minutes; seek medical attention if symptoms persist
- For skin contact: wash off immediately with plenty of water; seek medical attention if symptoms persist
- For ingestion: rinse mouth, drink plenty of water; seek medical attention if symptoms persist
- 24-hour emergency information: INFOTRAC at 800-535-5053
- Business hours contact: 785-865-4200 (8:00 AM–5:00 PM CST, Monday–Friday)
Frequently Asked Questions
Q: Is HCT Finishing Rinse a standalone product?
A: No. HCT Finishing Rinse is the second step in the two-step Conservare HCT system. It should be applied following Conservare HCT to complete the chemical reaction that forms the hydroxylated conversion layer.
Q: Will HCT Finishing Rinse change the appearance or gloss of the stone?
A: No. The product does not form a film and produces no gloss or yellowing. It is UV stable and does not alter the natural appearance of treated carbonate stone surfaces.
Q: Can HCT Finishing Rinse be used on polished marble or travertine?
A: No. The product is not suitable for use on polished marble, travertine, or limestone. It is also not suitable for fired clay, granite, sandstone, or slate substrates.
Q: Can HCT Finishing Rinse be used on concrete?
A: It may facilitate treatment of aged concrete or concrete with a predominance of carbonate aggregate, but testing is always required before application to confirm suitability.
Q: Is HCT Finishing Rinse VOC compliant?
A: Yes. HCT Finishing Rinse is compliant with all national, state, and district VOC regulations.
Q: What is the coverage rate for HCT Finishing Rinse?
A: Coverage is 50–80 sq ft per gallon. Refer to the Product Data Sheet for specific variations by substrate.