Westcoat WP-53 Hybrid Sealant
About
A Deck Flashing Sealant You Can Coat Over in About an Hour
On a waterproof walking deck, the metal flashing at the wall and the deck edge goes in as overlapping lengths, and every overlap is a place where water can work its way behind the system. Sealing those seams before the deck coating goes on is what keeps the flashing performing as one continuous, watertight edge.
WP-53 is a silyl-modified polymer (SMP), or modified hybrid silicone, sealant with high bond strength on bonderized sheet metal and plywood. It's tack free in about an hour at 72°F, and Westcoat cements, SC-10 Acrylic Topcoat, and WP-95 Waterproofing Membrane can be applied once it reaches that point. It's also formulated for use with asphaltic materials, it stays elastomeric after it cures, and it can be painted.
It's the flashing sealant in Westcoat's ALX, ALX Pro, and MACoat deck waterproofing systems, which are used on balconies, roof decks, and walkways for homes, hotels, condominiums, and apartment buildings.
Specs
Why Choose WP-53 Hybrid Sealant?
- Seals bonderized flashing seams and overlaps
- Tack free in about an hour
- Compatible with asphaltic materials
- Zero sag, easy-to-gun consistency
- Paintable and non-staining
- 49 g/L VOC
Westcoat Systems Using WP-53 Hybrid Sealant
WP-53 is the flashing sealant in Westcoat's ALX, ALX Pro, and MACoat waterproof deck systems. It's run between overlapped lengths of bonderized wall and drip edge flashing and along the seams, sealing the deck's perimeter before the waterproofing and texture coats are applied.
Waterproofing Systems
- ALX Standard Finish, ALX Custom Finish, ALX Pro Standard Finish, and ALX Pro Custom Finish | Two beads seal every flashing seam, with flashing ends overlapped at least 4"
- ALX and ALX Pro Waterproofing Underlayment | Two beads seal every flashing seam before the perimeter is wrapped in WP-95 Waterproofing Membrane and WP-45 Flashing Fabric
- MACoat Standard Finish | Caulks between overlapped flashing and along the seams
- MACoat Custom Finish | Caulks between overlapped flashing and along the seams, with WP-51 Polyurethane Sealant as the other specified option
Product Specifications for WP-53 Hybrid Sealant
SPECIFICATION DETAILS Product Type One-Component Hybrid Silicone (SMP) Sealant Color Gray Packaging 10 oz Cartridge or 20 oz Sausage (24 Units per Case) Coverage ~23 Linear Feet @ ¼" x ¼" Bead* Substrates Plywood, Bonderized Sheet Metal, and Other Common Construction Substrates Application Professional Caulking Gun Tack-Free Time ~60–65 Min @ 72°F and 48% RH** Full Cure ~24 Hours** Curing Rate Min. 3.5 mm/Day @ 73.4°F and 50% RH Application Temperature 50°F–90°F VOC Content 49 g/L Sag 0 mm Hardness Shore A 38 (28 Days) Tensile Strength 2.2 MPa Paintable Yes (Test Paint Compatibility First) Shelf Life Cartridge: 1 Year; Sausage: 18 Months (Unopened)
*Coverage is approximate and varies with bead size, joint dimensions, substrate, and application method. Refer to the current Technical Data Sheet for complete application and coverage information.
**Dry times are based on 72°F and 48% relative humidity. Lower temperatures and lower relative humidity will increase dry times.
How-To
Application Instruction Overview for WP-53 Hybrid Sealant
IMPORTANT! Before You Begin: Review the complete WP-53 Hybrid Sealant Technical Data Sheet (TDS) and Safety Data Sheet (SDS), linked above, along with the System Specification for the system you're installing. The information below is a brief overview and does not replace the manufacturer's complete application instructions.
Tools and Supplies
- Professional caulking gun
- Putty knife or joint tool
- Wire brush, sander, or grinder for surface preparation
Step 1 – Inspect and Prepare the Surface
- Surface must be structurally sound, dry, and free of laitance, oil, grease, curing agents, dirt, dust, or other foreign material that may prevent proper adhesion
- Clean the surface by wire brushing, sanding, or grinding
- Grind any coatings back to the concrete or plywood substrate
- Follow the System Specification for the system you're installing for complete preparation requirements
- Test the sealant's adhesion on the substrate
Step 2 – Apply WP-53
- WP-53 comes ready to use
- Cut the tip to the desired bead thickness and puncture the seal
- Apply with a professional caulking gun, and smooth with a putty knife or joint tool as needed
- Avoid entrapping air and overlapping material
- Use any opened cartridge the same day it's opened
Step 3 – Allow to Dry Before Coating
- Tack free in ~60–65 minutes at 72°F and 48% RH, with a total cure time of ~24 hours
- Lower temperatures and lower relative humidity will increase dry times
- Westcoat cements, SC-10 Acrylic Topcoat, and WP-95 Waterproofing Membrane may be applied once WP-53 is tack free
- Do not coat over WP-53 if it isn't dry
- Verify adhesion before applying any coating over WP-53
- Test all paints for compatibility before painting
Step 4 – Clean Up
- Clean uncured material with an environmentally safe solvent
- Remove cured material mechanically or with an environmentally safe solvent
Installation Limitations
- Do not apply to wet surfaces
- Not recommended for continuous water immersion applications
- Do not apply when ambient or substrate temperatures are below 50°F or above 90°F
- Hot or cold weather will affect dry times
- Store in cool, dry conditions
- Do not allow any Westcoat products to freeze
Full instructions
See More
FAQ
Frequently Asked Questions About WP-53 Hybrid Sealant
What is a hybrid sealant?
WP-53 is a silyl-modified polymer (SMP) sealant, also called a modified hybrid silicone. It's one-component, cures fast with high bond strength, stays elastomeric, and can be painted.
Can WP-53 be used with asphalt-based materials?
Yes. WP-53 is formulated for use with asphaltic materials, and it's compatible with WP-40 Sheet Membrane and WP-95 Waterproofing Membrane.
How soon can I coat over WP-53?
Once it's tack free, which takes about 60 to 65 minutes at 72°F and 48% relative humidity, you can apply Westcoat cements, SC-10 Acrylic Topcoat, or WP-95 Waterproofing Membrane. Cooler or drier conditions slow that down, so check that it's dry and verify adhesion before coating.
Can WP-53 be painted?
Yes, it's paintable. Test any paint for compatibility before applying it over the sealant.
Can WP-53 be used in areas that stay underwater?
No. WP-53 isn't recommended for continuous water immersion applications.
How long does WP-53 keep?
Unopened cartridges keep for one year and sausages for 18 months. Store them somewhere cool and dry, don't let them freeze, and use any opened cartridge the same day.
About
A Deck Flashing Sealant You Can Coat Over in About an Hour
On a waterproof walking deck, the metal flashing at the wall and the deck edge goes in as overlapping lengths, and every overlap is a place where water can work its way behind the system. Sealing those seams before the deck coating goes on is what keeps the flashing performing as one continuous, watertight edge.
WP-53 is a silyl-modified polymer (SMP), or modified hybrid silicone, sealant with high bond strength on bonderized sheet metal and plywood. It's tack free in about an hour at 72°F, and Westcoat cements, SC-10 Acrylic Topcoat, and WP-95 Waterproofing Membrane can be applied once it reaches that point. It's also formulated for use with asphaltic materials, it stays elastomeric after it cures, and it can be painted.
It's the flashing sealant in Westcoat's ALX, ALX Pro, and MACoat deck waterproofing systems, which are used on balconies, roof decks, and walkways for homes, hotels, condominiums, and apartment buildings.
Specs
Why Choose WP-53 Hybrid Sealant?
- Seals bonderized flashing seams and overlaps
- Tack free in about an hour
- Compatible with asphaltic materials
- Zero sag, easy-to-gun consistency
- Paintable and non-staining
- 49 g/L VOC
Westcoat Systems Using WP-53 Hybrid Sealant
WP-53 is the flashing sealant in Westcoat's ALX, ALX Pro, and MACoat waterproof deck systems. It's run between overlapped lengths of bonderized wall and drip edge flashing and along the seams, sealing the deck's perimeter before the waterproofing and texture coats are applied.
Waterproofing Systems
- ALX Standard Finish, ALX Custom Finish, ALX Pro Standard Finish, and ALX Pro Custom Finish | Two beads seal every flashing seam, with flashing ends overlapped at least 4"
- ALX and ALX Pro Waterproofing Underlayment | Two beads seal every flashing seam before the perimeter is wrapped in WP-95 Waterproofing Membrane and WP-45 Flashing Fabric
- MACoat Standard Finish | Caulks between overlapped flashing and along the seams
- MACoat Custom Finish | Caulks between overlapped flashing and along the seams, with WP-51 Polyurethane Sealant as the other specified option
Product Specifications for WP-53 Hybrid Sealant
| SPECIFICATION | DETAILS |
|---|---|
| Product Type | One-Component Hybrid Silicone (SMP) Sealant |
| Color | Gray |
| Packaging | 10 oz Cartridge or 20 oz Sausage (24 Units per Case) |
| Coverage | ~23 Linear Feet @ ¼" x ¼" Bead* |
| Substrates | Plywood, Bonderized Sheet Metal, and Other Common Construction Substrates |
| Application | Professional Caulking Gun |
| Tack-Free Time | ~60–65 Min @ 72°F and 48% RH** |
| Full Cure | ~24 Hours** |
| Curing Rate | Min. 3.5 mm/Day @ 73.4°F and 50% RH |
| Application Temperature | 50°F–90°F |
| VOC Content | 49 g/L |
| Sag | 0 mm |
| Hardness | Shore A 38 (28 Days) |
| Tensile Strength | 2.2 MPa |
| Paintable | Yes (Test Paint Compatibility First) |
| Shelf Life | Cartridge: 1 Year; Sausage: 18 Months (Unopened) |
*Coverage is approximate and varies with bead size, joint dimensions, substrate, and application method. Refer to the current Technical Data Sheet for complete application and coverage information.
**Dry times are based on 72°F and 48% relative humidity. Lower temperatures and lower relative humidity will increase dry times.
How-To
Application Instruction Overview for WP-53 Hybrid Sealant
IMPORTANT! Before You Begin: Review the complete WP-53 Hybrid Sealant Technical Data Sheet (TDS) and Safety Data Sheet (SDS), linked above, along with the System Specification for the system you're installing. The information below is a brief overview and does not replace the manufacturer's complete application instructions.
Tools and Supplies
- Professional caulking gun
- Putty knife or joint tool
- Wire brush, sander, or grinder for surface preparation
Step 1 – Inspect and Prepare the Surface
- Surface must be structurally sound, dry, and free of laitance, oil, grease, curing agents, dirt, dust, or other foreign material that may prevent proper adhesion
- Clean the surface by wire brushing, sanding, or grinding
- Grind any coatings back to the concrete or plywood substrate
- Follow the System Specification for the system you're installing for complete preparation requirements
- Test the sealant's adhesion on the substrate
Step 2 – Apply WP-53
- WP-53 comes ready to use
- Cut the tip to the desired bead thickness and puncture the seal
- Apply with a professional caulking gun, and smooth with a putty knife or joint tool as needed
- Avoid entrapping air and overlapping material
- Use any opened cartridge the same day it's opened
Step 3 – Allow to Dry Before Coating
- Tack free in ~60–65 minutes at 72°F and 48% RH, with a total cure time of ~24 hours
- Lower temperatures and lower relative humidity will increase dry times
- Westcoat cements, SC-10 Acrylic Topcoat, and WP-95 Waterproofing Membrane may be applied once WP-53 is tack free
- Do not coat over WP-53 if it isn't dry
- Verify adhesion before applying any coating over WP-53
- Test all paints for compatibility before painting
Step 4 – Clean Up
- Clean uncured material with an environmentally safe solvent
- Remove cured material mechanically or with an environmentally safe solvent
Installation Limitations
- Do not apply to wet surfaces
- Not recommended for continuous water immersion applications
- Do not apply when ambient or substrate temperatures are below 50°F or above 90°F
- Hot or cold weather will affect dry times
- Store in cool, dry conditions
- Do not allow any Westcoat products to freeze
FAQ
Frequently Asked Questions About WP-53 Hybrid Sealant
What is a hybrid sealant?
WP-53 is a silyl-modified polymer (SMP) sealant, also called a modified hybrid silicone. It's one-component, cures fast with high bond strength, stays elastomeric, and can be painted.
Can WP-53 be used with asphalt-based materials?
Yes. WP-53 is formulated for use with asphaltic materials, and it's compatible with WP-40 Sheet Membrane and WP-95 Waterproofing Membrane.
How soon can I coat over WP-53?
Once it's tack free, which takes about 60 to 65 minutes at 72°F and 48% relative humidity, you can apply Westcoat cements, SC-10 Acrylic Topcoat, or WP-95 Waterproofing Membrane. Cooler or drier conditions slow that down, so check that it's dry and verify adhesion before coating.
Can WP-53 be painted?
Yes, it's paintable. Test any paint for compatibility before applying it over the sealant.
Can WP-53 be used in areas that stay underwater?
No. WP-53 isn't recommended for continuous water immersion applications.
How long does WP-53 keep?
Unopened cartridges keep for one year and sausages for 18 months. Store them somewhere cool and dry, don't let them freeze, and use any opened cartridge the same day.
