11
Buy in Bulk and Save!
Price Per Unit: $6.40
Price Per Box: $5.76
N-40: A Technical Overview
Born from decades of on-site experience, Adheseal N-40 is the ultimate general-purpose silicone sealant, formulated to be the most versatile and reliable tube in any toolbox. Since 1989, it has been the trusted choice for Australian trades who need one product to do it all. Its neutral cure (oxime) chemistry ensures it won't corrode sensitive metals like Zincalume® or galvanised steel, while its built-in anti-fungal properties make it ideal for sanitary applications. N-40 delivers a high-strength, permanently flexible, and UV-stable bond to an unparalleled range of substrates, making it the definitive solution for countless applications.
±25%
Joint Movement Capability. N-40 accommodates significant structural movement, thermal expansion, and vibration without cracking or losing adhesion, ensuring a durable, long-lasting seal in dynamic building joints.
Core Features & Specifications
- Universal Adhesion: Bonds tenaciously to Zincalume®, Colorbond®, galvanised steel, glass, aluminium, PVC, timber, tiles, and most common construction materials.
- Neutral Cure System: Non-corrosive chemistry is safe for metals and concrete, preventing rust and surface damage common with cheaper acetoxy silicones.
- Extreme Temperature Resistance: Maintains permanent flexibility and performance in service temperatures from a frigid -50°C up to +150°C.
- Anti-Fungal & Sanitary: Contains a powerful fungicide to inhibit the growth of mould and mildew, making it ideal for bathrooms, kitchens, and laundries. Also certified safe for food preparation areas.
- Low VOC Compliance: With a VOC content of just 43g/L, N-40 meets Green Star environmental criteria, making it suitable for modern, sustainable building projects.
- Durable & UV Stable: Designed to withstand permanent UV exposure without cracking, yellowing, or breaking down, ensuring a long-lasting external seal.
The N-40 Advantage
- Simplify Your Inventory: Carry one tube that does the job of many. N-40's versatility means less searching for the right product and more time getting the job done.
- Work with Confidence: A proven performer for over 30 years, N-40 delivers a reliable seal you can trust, reducing the risk of costly and reputation-damaging call-backs.
- Protect Your Work: The non-corrosive formula protects your client's assets, from metal roofs to concrete panels, ensuring the sealant doesn't become the source of a future problem.
- Seal Any Environment: From hot, humid bathrooms to freezer rooms and sun-beaten roofs, N-40's robust formulation handles it all with ease.
- Achieve a Cleaner Finish: Low odour and easy tooling allow for a professional result every time, whether you're a plumber, builder, or shopfitter.
Best Practices: Do's & Don'ts
Do
- Ensure all surfaces are structurally sound, completely dry, and clean of all dust, oil, and loose material.
- Use the two-wipe process with a clean solvent like White Spirits for preparing non-porous surfaces.
- Design joints with a 2:1 width-to-depth ratio where possible for optimal flexibility and performance.
- Use a backing rod for any joint deeper than 10mm to control sealant depth and ensure a two-sided bond.
- Tool off the sealant within 5-10 minutes of application using a moistened spatula for a smooth, professional finish.
Don't
- Do not apply in totally confined spaces; the sealant requires atmospheric moisture to cure properly.
- Do not use on natural stone like marble or granite without performing a preliminary stain test.
- Do not use for continuous underwater applications such as swimming pools or in aquariums.
- Do not attempt to paint over the sealant, as paint will not adhere to the cured silicone surface.
- Avoid using on polycarbonate sheeting or for structural glazing applications, which require specialised products.
Applications in Practice: Trade Scenarios
For Plumbers & Roofers: Weatherproof Sealing
The On-Site Challenge
You need to seal roof flashings, gutters, and penetrations on a Colorbond® roof. The sealant must be UV stable, waterproof, flexible enough to handle thermal expansion, and critically, must not cause corrosion on the metal sheeting.
The System-Based Solution with N-40
N-40's neutral cure chemistry is non-corrosive, making it the perfect choice for Zincalume®, galvanised steel, and Colorbond®. Its ±25% joint movement capability handles the expansion and contraction of metal roofing sheets, while its excellent UV resistance prevents it from breaking down under the harsh Australian sun.
Best Practice Note
Ensure the metal surface is oil-free and dry. For a clean finish on visible flashings, mask both sides of the joint before applying the sealant and remove the tape immediately after tooling.
For Builders & Carpenters: General Construction Sealing
The On-Site Challenge
A typical day involves sealing around window frames, skirting boards, and expansion joints across multiple materials like aluminium, PVC, and treated timber. You need one reliable sealant that adheres to everything without needing multiple products.
The System-Based Solution with N-40
N-40 is the ultimate multi-tool. Its formulation provides excellent, unprimed adhesion to the vast majority of building materials. This versatility means you can confidently move from sealing an aluminium window to a PVC pipe penetration, and then to a timber expansion joint, all with the same tube.
Best Practice Note
For deep joints (over 10mm), insert a closed-cell backing rod to the correct depth. This not only saves sealant but ensures the joint has the ideal 2:1 width-to-depth ratio for maximum movement capability.
Performance Benchmark: N-40 vs. Standard Acetoxy Silicone
| Metric | N-40 (Neutral Cure) | Standard Acetoxy Cure | Advantage |
|---|---|---|---|
| Metal Corrosion | Non-corrosive Excellent | Corrosive to some metals | Safe to use on Zincalume®, Colorbond®, and galvanised steel without risk of causing rust. |
| Adhesion Range | Excellent on most surfaces Versatile | Limited, poor on concrete/metals | Provides reliable adhesion to a much broader range of building materials, including plastics and masonry. |
| Odour During Cure | Low Odour Good | Strong vinegar smell | More pleasant to work with, especially in enclosed or poorly ventilated interior spaces. |
| Joint Movement | ±25% High Flexibility | Typically ±20% or less | Superior flexibility accommodates more building movement, leading to a more durable, crack-free seal. |
Frequently Asked Questions
Can N40 GP Silicone be used in bathrooms and wet areas?
N40 GP Silicone Sealant – Standard Colours is formulated with anti-fungal agents, making it highly suitable for bathrooms, showers, laundries, and kitchens. It maintains a waterproof seal even in high-humidity environments and is compliant with sanitary sealing requirements.
Is this silicone safe for use on metals like zincalume or galvanised steel?
Yes, N40 is neutral curing and does not corrode sensitive metals. It is compatible with galvanised, zincalume, aluminium, and stainless steel, making it ideal for both roofing and flashing applications.
What is the skin time and curing rate of N40 GP Silicone?
N40 has a skin time of approximately 10 minutes, and it cures at a rate of ~2mm per 24 hours at 25°C and 50% RH. Actual cure times may vary based on humidity, temperature, and substrate porosity.
Can I paint over N40 GP Silicone Sealant?
No. N40 is not a paintable silicone. For applications where a paintable finish is required, consider using an acrylic sealant or a product specifically designed to be overcoated.
What substrates require priming before using N40?
Most surfaces do not require priming, but for critical or porous substrates, use Adheseal Primer 50A (non-porous) or Primer 2001 (porous). Always perform an adhesion test before large-scale application.
Applications & Benefits
| Application / Use Case | Key Benefit | Primary Trades |
|---|---|---|
| Bathroom & Kitchen Sealing | Anti-fungal, mould-resistant and flexible in wet areas | Plumbers, Builders, Tilers |
| Window & Glazing Seals | UV stable with no corrosion on metal frames | Glaziers, Builders |
| Commercial Joinery / Shopfitting | Adheres to laminated surfaces, PVC, and timber | Joiners, Fitout Contractors |
| Aircon, Electrical & Roofing Penetrations | Permanently flexible for vibration-prone installations | HVAC, Electricians, Roofers |
| Marine or Vehicle Bodywork | Weatherproof and vibration-resistant for moving assemblies | Auto Fabricators, Marine Installers |
Applying N40 GP Silicone Sealant: Enhanced Protocols & Best Practices
-
1. Surface Preparation
Ensure surfaces are structurally sound, dry, and free of oils, dust, or contaminants. Use a two-cloth wipe method with white spirit on impervious materials. For rough surfaces, remove loose material and clean thoroughly.
Tiling / Sanitary
Wipe with white spirit, dry, and mask adjacent tiles to avoid smears.
Metal or Cladding
Degrease aluminium and coated steel with solvent wipes. Do not sand powder-coated surfaces.
Timing: Clean immediately prior to sealing to reduce dust recontamination.Pro Tip: Change cloths frequently and use fresh solvent to avoid spreading grime. -
2. Joint Design & Backing
Design joints with a 2:1 width-to-depth ratio where possible. Use backing rod to limit depth and avoid three-point adhesion. Joints wider than 10mm must use backing rod or bond breaker tape.
Interior Seals
Minimum joint: 5mm x 5mm. Foam rod used where depth exceeds 6mm.
Expansion / External
Use closed-cell rod 25% larger than joint width. Prevents excessive sealant consumption and ensures optimal joint movement.
Timing: Install rod before sealant to control bond geometry.Pro Tip: Ensure sealant adheres to only two sides — never all three — to prevent premature failure. -
3. Sealant Application
Cut nozzle at 45° to match joint width. Insert cartridge into caulking gun and apply with steady pressure, pushing the bead ahead of the nozzle to achieve full contact with both sides of the joint.
Manual Application
Use even pressure on trigger. Apply a continuous bead with no gaps. Avoid pulling the gun, which may create air pockets.
Compressed Air Gun
Set to 2–3 bar for controlled dispensing. Suitable for long runs or professional joinery use.
Timing: Tool off within 5 minutes. Skin time is ~10 minutes at 25°C, 50% RH.Pro Tip: Use a wet spatula for tooling. Remove masking tape before skin forms to achieve clean edges. -
4. Curing & Cleanup
Let silicone cure undisturbed for 24–48 hours depending on joint depth. Clean uncured material with white spirit. Do not expose to moisture during initial curing phase.
Uncured Silicone
Wipe immediately with lint-free cloth dampened with solvent. Tooling residue can be cleaned with white spirit.
Cured Silicone
Remove mechanically using a scraper or silicone removal tool. Avoid harsh abrasives.
Timing: Allow 24 hours per 2mm depth of sealant for full cure at 25°C and 50% RH.Pro Tip: Avoid washing or painting over joints during cure. Protect from foot traffic or weather until full set.
Limitations & Safety
Product Limitations
Not suitable for structural glazing – use N-80 or N-60 instead.
Do not use in aquariums or submerged applications. Not rated for underwater adhesion.
Unsuitable for use on natural stone surfaces – may cause staining. Perform stain testing or use specialist stone silicone.
Not recommended for horizontal trafficable joints (e.g., walkways or tiled floors).
Avoid using on polycarbonate sheets. Compatibility issues may lead to discoloration or failure.
Not paintable – use paintable acrylic sealant if surface coating is required.
Safety & Handling Requirements
Personal Protective Equipment
Wear nitrile gloves and safety glasses when applying. Avoid prolonged skin contact. Suitable protective clothing should be worn if working in overhead applications.
Ventilation Requirements
Use in a well-ventilated area. Avoid inhaling vapours during application and cure. Mechanical ventilation may be required in enclosed spaces.
Fire & Handling Precautions
Keep away from open flame or ignition sources during application. Store in cool, dry conditions away from oxidising agents.
Emergency First Aid
Eyes:
Flush with lukewarm, gentle flowing water for at least 5 minutes. Seek medical attention if irritation persists.
Skin:
Wipe off excess, wash skin with soap and water. If irritation develops, consult a doctor.
Inhaled:
Move to fresh air. Seek medical attention if symptoms such as dizziness or headache persist.
Swallowed:
Do not induce vomiting. Rinse mouth and drink water. Contact Poisons Information Centre or doctor immediately.
Seek medical attention immediately in all cases of serious exposure.
N40 GP Silicone Sealant Application Guide
Glass & Ceramic Tiles
Surface Preparation
Clean using a two-cloth method and white spirit. Remove soap residue, oil, and dust. Dry completely before sealing.
No primer typically required
Ensure surface is sound, dry and free from film or treatment residues.
Aluminium, Zincalume & Colorbond®
Surface Preparation
Degrease with clean solvent cloths. Avoid abrading coated or anodised surfaces. Do not apply to oxidised or flaking finishes.
Primer recommended for optimal adhesion
Use Primer 50A in critical joints or where long-term water exposure is expected.
Primer 50ATimber, Plywood & Laminated Surfaces
Surface Preparation
Ensure substrate is dry, stable, and free from dust or treatment residues. Lightly sand glossy finishes and wipe down.
Primer required for porous substrates
Use Primer 2001 for raw or absorbent timber substrates.
Primer 2001PVC & Plastics
Surface Preparation
Clean gently using white spirit. Avoid aggressive solvents or abrasives. Dry fully before applying sealant.
Primer recommended for optimal adhesion
Use Primer 50A for high-movement joints or vertical surfaces.
Primer 50AConcrete, Masonry & Cement Sheeting
Surface Preparation
Allow full cure (28 days for concrete). Remove laitance and debris. Surface must be dry and free from curing compounds.
Primer required for porous substrates
Apply Primer 2001 and allow to flash off before sealing.
Primer 2001
- Choosing a selection results in a full page refresh.