{"product_id":"bostik-seal-n-flex-one-p390-polyurethane-sealant-300ml","title":"Bostik Seal 'N' Flex One P390 Polyurethane Sealant 300ml","description":"\u003cdiv role=\"main\" data-content-type=\"product\" aria-label=\"Product Description for Bostik Seal 'N' Flex One P390\"\u003e\n\n  \u003csection class=\"product-content-section\" aria-labelledby=\"opening-heading\"\u003e\n    \u003cp class=\"opening-narrative\"\u003e\n      When an expansion joint must move with the building, perform in challenging conditions, and meet strict certifications, the right sealant is non-negotiable. Bostik Seal 'N' Flex One P390 provides this assurance. It is engineered for high-movement applications in concrete, masonry, and precast panels, ensuring seals remain intact where flexibility and compliance are paramount.\n    \u003c\/p\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"product-content-section\" aria-labelledby=\"positioning-heading\"\u003e\n    \u003ch3 id=\"positioning-heading\"\u003eWhy this product exists\u003c\/h3\u003e\n    \u003cp\u003eBostik Seal 'N' Flex One P390 is a low modulus, one-component polyurethane sealant formulated for the demands of Australian construction. It maintains a durable, flexible seal across an impressive ±50% joint movement. This capability prevents common joint failures, especially in dynamic structures like tilt-up panels or concrete slabs. With over 900% elongation at break, it provides a substantial safety margin, absorbing thermal shock and minor settlement that could compromise lesser sealants. This product was developed to deliver reliable performance where AS4020 potable water approval or acoustic rating is required for expansion and construction joints.\u003c\/p\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"product-content-section\" aria-labelledby=\"specs-heading\"\u003e\n    \u003ch3 id=\"specs-heading\"\u003eThe numbers that matter\u003c\/h3\u003e\n    \u003cul\u003e\n      \u003cli\u003e\n\u003cstrong\u003eTotal Joint Movement: ±50%\u003c\/strong\u003e. This Class-A movement rating means a 20mm joint can expand and contract by 10mm without bond failure, making it suitable for significant structural movement.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eElongation at Break: \u0026gt;900%\u003c\/strong\u003e. While rated for ±50% movement, its extreme elongation capacity provides exceptional resilience against unexpected stresses, minor substrate shifts, or temperature extremes, significantly reducing the risk of premature failure.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eShore A Hardness: 30\u003c\/strong\u003e. This low modulus value indicates a soft, flexible sealant that readily accommodates joint movement, transferring minimal stress to bond lines and ensuring long-term adhesion.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eCure Rate: 2mm per 24 hours\u003c\/strong\u003e. This allows for sufficient tooling time (6-12 hours tack-free) while ensuring a steady, predictable cure to full strength over 7 days (or 14 days for joints exceeding 20mm width). This controlled cure minimises the risk of cracking in the sealant film during early movement cycles.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"product-content-section\" aria-labelledby=\"experience-heading\"\u003e\n    \u003ch3 id=\"experience-heading\"\u003eWhat it's like to use\u003c\/h3\u003e\n    \u003cp\u003eBostik Seal 'N' Flex One P390 is supplied as a one-component system, requiring no mixing, simplifying on-site application. It can be applied in temperatures ranging from 5°C to 35°C using a standard caulking gun. For optimal performance, ensure all surfaces are clean and dry, free from contaminants. While the sealant offers good adhesion to many substrates without a primer, critical or high-performance applications, especially on porous surfaces or those subject to periodic immersion, benefit from Bostik N49 Primer. For non-porous plastics and metals, Bostik N40 Primer is recommended using a two-cloth method. Tooling should occur within the tack-free time to achieve a smooth, concave finish. Once cured (minimum 7 days), the sealant can be painted, though a field test for compatibility with solvent-based coatings is always recommended. Always use a compatible backer rod to control sealant depth and prevent three-sided adhesion.\u003c\/p\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"product-content-section\" aria-labelledby=\"applications-heading\"\u003e\n    \u003ch3 id=\"applications-heading\"\u003eWhere this product excels\u003c\/h3\u003e\n    \u003cul\u003e\n      \u003cli\u003e\n\u003cstrong\u003eConcrete and Masonry Expansion Joints:\u003c\/strong\u003e For sealing expansion joints in in-situ concrete, precast, tilt-up panels, brickwork, and blockwork, it handles significant cyclic movement (±50%) without cracking or bond failure.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003ePotable Water Infrastructure:\u003c\/strong\u003e Certified to AS4020 for contact with drinking water, it is ideal for sealing joints in water storage tanks, reservoirs, and piping systems where water quality is critical.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eAcoustic Sealing:\u003c\/strong\u003e Acoustic rated to AS 2253 \/ 1276, it effectively reduces sound transmission through joints in plasterboard and fibre cement sheets, crucial for quiet commercial or residential spaces.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eSpecialty Panel Systems:\u003c\/strong\u003e Its low modulus and high elongation make it well-suited for sealing joints in GRC, fibreglass, and other specialty panel systems, accommodating their dynamic movement.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"value-proof-banner\" aria-label=\"Compliance\"\u003e\n    \u003cp\u003e\n      \u003cstrong\u003eAS4020 Potable Water Approval:\u003c\/strong\u003e This certification confirms suitability for contact with drinking water, essential for compliant water infrastructure projects. \u003cstrong\u003eAS 2253 \/ 1276 Acoustic Rating:\u003c\/strong\u003e Provides verified performance in reducing sound transmission, supporting acoustic design requirements in commercial and residential builds. \u003cstrong\u003eASTM C.920-87 \u0026amp; 98 Class 50:\u003c\/strong\u003e Independently verified for Type S, Grade NS, Class 50 performance, ensuring the specified movement capability and durability under a range of conditions.\n    \u003c\/p\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"product-content-section\" aria-labelledby=\"decision-heading\"\u003e\n    \u003ch3 id=\"decision-heading\"\u003eChoose this when\u003c\/h3\u003e\n    \u003cul\u003e\n      \u003cli\u003e\n\u003cstrong\u003eWhen you need ±50% movement capacity:\u003c\/strong\u003e Specify for expansion and construction joints in concrete, precast, or masonry where significant, ongoing movement is expected.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eWhen potable water contact is required:\u003c\/strong\u003e Use in applications where the sealant will be in contact with drinking water, such as water tanks or reservoirs, ensuring AS4020 compliance.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eWhen acoustic performance matters:\u003c\/strong\u003e Select for sealing plasterboard or fibre cement joints where sound transmission needs to be minimised and a certified acoustic rating is beneficial.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eWhen durability and flexibility are critical:\u003c\/strong\u003e Opt for this sealant in environments with temperature fluctuations or structural settling, leveraging its high elongation at break to maintain integrity.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"product-content-section\" aria-labelledby=\"limitations-heading\"\u003e\n    \u003ch3 id=\"limitations-heading\"\u003eDon't use this when\u003c\/h3\u003e\n    \u003cul\u003e\n      \u003cli\u003e\n\u003cstrong\u003eNot for:\u003c\/strong\u003e Chlorinated water immersion, such as swimming pools or spas, as it is not formulated for these chemical environments.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eNot for:\u003c\/strong\u003e Glazing applications or on any material containing bitumen, which can lead to compatibility issues or staining.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eNot for:\u003c\/strong\u003e Applying to cement-based substrates within 28 days of initial pour or set, as uncured concrete can affect adhesion and cure.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eNot for:\u003c\/strong\u003e Trafficable joints, as its low Shore A hardness and modulus are not designed to withstand pedestrian or vehicular traffic.\u003c\/li\u003e\n      \u003cli\u003e\n\u003cstrong\u003eNot for:\u003c\/strong\u003e Extreme movement joints exceeding ±50%, as a dedicated high-movement sealant like Seal 'N' Flex One Plus P590 would be a more suitable choice.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"product-content-section\" aria-labelledby=\"sibling-heading\"\u003e\n    \u003ch3 id=\"sibling-heading\"\u003eBostik Seal 'N' Flex One P390 vs. Seal 'N' Flex One Plus P590\u003c\/h3\u003e\n    \u003cp\u003eBostik Seal 'N' Flex One P390 is the go-to for expansion and construction joints requiring robust ±50% movement and specific certifications like AS4020 potable water approval and acoustic rating. It is a proven performer for standard high-movement applications on dry substrates. In contrast, for joints demanding extreme movement capacity, exceeding ±50% (up to +100%\/-50%), or where application on damp or even wet concrete substrates is necessary, Seal 'N' Flex One Plus P590 offers a more advanced solution. The choice between them hinges on the precise movement profile and substrate conditions of the project.\u003c\/p\u003e\n  \u003c\/section\u003e\n\n\n\u003csection class=\"product-content-section\" aria-labelledby=\"related-products-heading\" id=\"related-products-links\"\u003e\n  \u003ch3 id=\"related-products-heading\"\u003eRelated products\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/bostik-seal-n-flex-one-plus-p590\"\u003eBostik Seal ‘N’ Flex One Plus P590\u003c\/a\u003e\u003c\/li\u003e\n    \u003cli\u003e\u003ca href=\"\/products\/fireban-one\"\u003eBostik Fireban One\u003c\/a\u003e\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\u003c\/div\u003e","brand":"Bostik","offers":[{"title":"Box Buy (20) \/ Grey","offer_id":48530760040640,"sku":"SNFFCGR\/CTG\/BOX","price":355.8,"currency_code":"AUD","in_stock":true},{"title":"Box Buy (20) \/ White","offer_id":48530760073408,"sku":"SNFFCWH\/CTG\/BOX","price":355.8,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0507\/3630\/0224\/files\/sealnflex1.png?v=1782886428","url":"https:\/\/adheseal.com.au\/products\/bostik-seal-n-flex-one-p390-polyurethane-sealant-300ml","provider":"Adheseal","version":"1.0","type":"link"}