--- title: Selleys 635 Multipurpose Elastic Joint Sealant - canonical_url: https://directory.selleys.com.au/sealants/multi-purpose/selleys-635-multipurpose-elastic-joint-sealant/ category: description: geography: city: state: country: metadata: phone: email: website: publishedAt: productInfo: stock: True productFeedItemId: b4473153-efd8-451e-a0d4-5ec21134df43 --- # Selleys 635 Multipurpose Elastic Joint Sealant - ## AI Summary **Product:** Selleys 635 Multipurpose Elastic Sealant Clear 290mL **Brand:** Selleys **Category:** Silicone Sealant **Primary Use:** Elastic, neutral-cure silicone sealing across residential, commercial, and light industrial building and construction applications involving mixed substrates and movement-prone joints. ### Quick Facts - **Best For:** Builders, tradespeople, and DIYers sealing wet areas, glazing, expansion joints, and mixed-material joints where aesthetics and substrate sensitivity matter - **Key Benefit:** Neutral cure chemistry releases no acetic acid, protecting mirrors, natural stone, copper, brass, and zinc-galvanised steel from corrosion or acid etching - **Form Factor:** Clear, paste-consistency silicone sealant in a 290mL cartridge (product code 103355, barcode 9300697132956) - **Application Method:** Load into standard caulking gun, cut nozzle at 45 degrees, apply continuous bead, tool immediately with soapy water ### Common Questions This Guide Answers 1. Is this sealant safe for mirrors and natural stone? → Yes; neutral cure releases alcohol or oxime compounds instead of acetic acid, preventing damage to silvered backings and stone surfaces 2. What hazards does this product carry? → Classified hazardous under Safe Work Australia GHS 7 for Skin Sensitisation Category 1 (H317) and Eye Damage/Irritation Category 2A (H319); not classified as Dangerous Goods for transport 3. What PPE is required when using this product? → Nitrile rubber gloves, safety glasses with side shields minimum, protective clothing, and safety shoes; contaminated clothing must not leave the workplace and must be washed before reuse --- ## Product overview Selleys 635 Multipurpose Elastic Sealant Clear delivers reliable, elastic sealing performance across a wide range of building and construction applications (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). Packaged in a 290mL cartridge with product code 103355 (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), this clear, neutral-cure silicone sealant gets the job done while staying visually unobtrusive in finished work. It's a genuinely multipurpose sealant, engineered to bond to multiple substrate types without needing specialised variants for every material. That versatility pays off on projects involving mixed materials, or wherever a single sealant needs to handle multiple sealing functions throughout a job. The cured sealant stretches and compresses with joint movement, holding firm against thermal expansion, structural settlement, and vibration without cracking or losing adhesion. The clear formulation stays transparent after curing, making it the right choice wherever the sealant bead needs to stay inconspicuous or where it spans varied substrate colours. Neutral cure chemistry means no acetic acid release during curing, so sensitive materials like mirrors, natural stone, and certain metals stay protected and undamaged. ## Chemistry & composition Selleys 635 is built on a silicone polymer matrix modified with reactive silane compounds that drive adhesion and cure. Three primary silane components work together, each playing a distinct role in the sealant's performance (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). 1-Propanamine, 3-(trimethoxysilyl)- makes up 1–10% by weight (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) and acts as an adhesion promoter. This amino-functional silane forms chemical bonds with substrate surfaces, particularly important for strong adhesion to glass, metals, and certain plastics. The trimethoxy groups react with moisture to form silanol groups that bond directly onto substrate surfaces. Silane, trimethoxy[3-(oxiranylmethoxy)propyl]-, also at 1–10% by weight (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), is an epoxy-functional silane that strengthens adhesion across a broader set of substrates and contributes to the moisture-cure mechanism. The epoxy group provides reactive sites for crosslinking and substrate bonding. Trimethoxyvinylsilane, again at 1–10% by weight (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), acts as a crosslinker that builds the three-dimensional polymer network during cure. The vinyl functionality drives the crosslinking reactions that transform the liquid sealant into a tough, elastic solid. UV stabilisers round out the formulation to guard against sunlight degradation. Bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and Methyl (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate are both present at less than 1% by weight (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). These hindered amine light stabilisers (HALS) neutralise free radicals before they can break down polymer chains, preventing the yellowing, embrittlement, and elasticity loss that UV exposure would otherwise cause over time. A Hydroxyphenylbenzotriazole derivative at less than 1% by weight (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) functions as a UV absorber, blocking UV radiation from penetrating into the sealant mass. This dual approach, absorption and stabilisation working together, is especially important in a clear sealant that cannot rely on pigments to shield against light. The balance of the formulation consists of ingredients determined to be non-hazardous or below reporting limits (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), which typically includes the silicone polymer base, fillers, plasticisers, and cure catalysts. ## Technical specifications **Product identification:** - Full product name: Selleys 635 Multipurpose Elastic Sealant Clear 290mL (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) - Product code: 103355 (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) - Barcode: 9300697132956 (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) - Package size: 290mL cartridge (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) **Regulatory classifications:** The product is classified as hazardous under Safe Work Australia GHS 7 criteria (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), specifically for skin sensitisation and eye irritation. It is not classified as Dangerous Goods under the Australian Code for the Transport of Dangerous Goods by Road & Rail or the New Zealand NZS5433 standard (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). That distinction matters practically: the product requires hazard labelling and careful handling, but not dangerous goods placarding, documentation, or special transport procedures, keeping logistics straightforward for professional and retail distribution. The absence of a Hazchem Code (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) confirms that emergency responders do not need specialised chemical response protocols for this product. There is no Poisons Schedule designation (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), meaning the product is not subject to scheduling restrictions under therapeutic goods or poisons regulations. **Fire characteristics:** Selleys 635 is classified as a combustible material (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). It will burn if involved in a fire but does not meet the criteria for flammable classification. In fire situations, the material may emit toxic fumes upon burning or decomposition (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), which is typical of organic polymers and silicone materials. Suitable extinguishing media include water fog, fine water spray, alcohol-resistant foam, standard foam, dry chemical powder, or carbon dioxide (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). The range of acceptable agents gives emergency responders flexibility based on available equipment and the nature of the surrounding fire. ## Key features & performance benefits **Multipurpose substrate compatibility:** Three different functional silanes create a broad adhesion spectrum across a wide range of materials. The amino-functional silane bonds strongly to inorganic surfaces like glass and metal. The epoxy-functional silane drives adhesion to plastics and porous materials. This multi-mechanism system lets a single product seal joints between dissimilar materials, glass to metal, PVC to timber, acrylic to ceramic, without primers in most applications. **Elastic movement accommodation:** The crosslinked silicone network formed during cure creates a permanently elastic seal that stretches and compresses repeatedly without tearing or debonding. That elasticity is essential for joints subject to thermal cycling, structural movement, or vibration. Rigid sealants crack under movement; Selleys 635 holds firm, maintaining a continuous, watertight seal throughout the joint's service life. **Neutral cure chemistry:** Neutral cure sets this product apart from acetic acid-curing silicones, the ones that smell like vinegar. Neutral cure formulations release alcohol or oxime compounds during cure rather than acetic acid, eliminating any risk of corrosion on sensitive metal substrates like copper, brass, or zinc-galvanised steel. That makes Selleys 635 the right call for sealing around mirrors (where acetic acid attacks the silvered backing), on natural stone or marble (where acid etches the surface), and in applications involving electronic components sensitive to corrosive vapours. **UV resistance:** The dual UV protection system combining HALS stabilisers and UV absorbers (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) holds up against the sunlight exposure that degrades lesser polymer sealants over time. HALS compounds neutralise free radicals formed when UV radiation interacts with polymer chains. The benzotriazole UV absorber stops radiation from penetrating the sealant mass. Together, they maintain the sealant's elasticity, adhesion, and clarity through years of outdoor exposure. **Clear appearance:** The transparent formulation stays visually unobtrusive after cure, a real advantage wherever aesthetics matter. On glass installations, the clear bead is virtually invisible. Over coloured or patterned tiles, it adapts visually to the background. In shower recesses or kitchen splashbacks where grout lines and surface patterns already create visual complexity, a clear sealant avoids introducing colour that clashes or demands careful matching. ## Applications & use cases Selleys 635 works across residential, commercial, and light industrial applications wherever a durable, elastic, moisture-resistant seal is required. **Sanitary and wet area sealing:** Selleys 635 handles constant water exposure reliably. It seals around bathtubs, shower bases, vanity tops, and kitchen sinks without compromise. The neutral cure chemistry protects chrome fixtures and brass fittings from corrosion, while the elastic properties accommodate differential movement between ceramic tiles and acrylic or fibreglass fixtures. Moisture resistance prevents water ingress that leads to substrate damage or mould growth behind sealed joints. **Glazing applications:** The clear formulation and glass-compatible adhesion chemistry make this sealant well suited for sealing around windows, glass panels, and glazed doors. It bonds to glass, aluminium frames, timber joinery, and PVC extrusions found throughout window systems. UV resistance ensures long-term performance on exterior glazing in direct sunlight. Neutral cure keeps aluminium frames protected and mirror backings intact. **General construction sealing:** Across broader construction work, Selleys 635 seals expansion joints, control joints, and perimeter joints wherever movement accommodation is required. It handles joints between different building materials, metal flashing to masonry, PVC cladding to timber framing, fibre cement sheeting to window frames. The multipurpose adhesion means less time managing multiple specialised sealants for different substrate combinations. **Appliance and fixture installation:** When installing appliances, light fixtures, or plumbing fixtures, Selleys 635 provides a reliable moisture barrier and accommodates the slight movement that occurs during use. Sealing around range hoods, exhaust fans, wet area light fixtures, and plumbing penetrations through walls or floors all benefit from the product's water resistance and elastic performance. ## Application guidelines **Surface preparation:** Good surface preparation is the foundation of a lasting bond. Every joint surface must be clean, dry, and free from anything that could interfere with adhesion. Remove dust, dirt, oil, grease, old sealant residues, release agents, and any loose or friable material from joint faces. For previously sealed joints, remove the old sealant completely; silicone does not bond reliably to aged silicone surfaces. Porous substrates like concrete, masonry, or unsealed timber must be dry before application. Trapped moisture under the sealant undermines both cure and adhesion. Non-porous surfaces like glass, glazed tile, or metal respond well to cleaning with an appropriate solvent, methylated spirits or isopropyl alcohol work well, to remove oils and residues. Let surfaces dry completely before applying sealant. **Joint design considerations:** Specific joint width and depth ratios are not provided in the available documentation. Generally, silicone sealants perform best when joint depth is approximately half the joint width, and when the sealant bonds only to the two opposing joint faces, not the base. Backer rod or bond breaker tape at the joint base prevents three-sided adhesion, which overstresses the sealant and leads to premature joint failure. **Application technique:** Load the 290mL cartridge into a standard caulking gun. Cut the nozzle at a 45-degree angle to the desired bead size, smaller for narrow joints, larger for wide ones. Apply the sealant in a continuous bead along the joint, maintaining steady trigger pressure to keep bead volume consistent with no gaps. Tool the bead immediately after application for a neat finish and strong substrate contact. Use a wet finger, wet spatula, or purpose-designed sealant finishing tool dipped in soapy water to smooth the bead and press it firmly into the joint. Tooling pushes sealant into surface irregularities, removes excess material, and creates a concave profile that sheds water effectively. The soapy water stops the sealant sticking to the tool and delivers a smooth, professional surface finish. **Cure conditions:** Selleys 635 cures through reaction with atmospheric humidity. Cure progresses from the exposed surface inward, with the rate depending on joint depth, temperature, and relative humidity. Higher humidity and moderate temperatures speed up cure. Low humidity, cold temperatures, or deep joint sections slow things down. Keep the sealant undisturbed during cure; no stress, water immersion, or cleaning chemical exposure. Silicone sealants typically develop enough surface cure to resist light contact within a few hours. Full cure through deep sections may take several days. ## Safety considerations & hazards **Hazard classification:** Selleys 635 is classified as hazardous with a "Warning" signal word (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) under two hazard categories: 1. **Skin Sensitisation – Category 1:** The product may cause an allergic skin reaction (H317) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). Repeated or prolonged skin contact can lead to sensitisation, where the immune system develops a reaction to one or more components. Once sensitised, even small amounts of exposure can trigger allergic dermatitis, redness, itching, swelling, and rash. 2. **Eye Damage/Irritation – Category 2A:** The product causes serious eye irritation (H319) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), producing immediate discomfort, redness, and potential temporary vision impairment on eye contact. **Personal protective equipment:** Protective gloves, protective clothing, and eye/face protection are mandatory (P280) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). In practice, that means: - **Gloves:** Nitrile rubber gloves are suitable for intermittent contact, though users should assess based on glove construction and actual conditions (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). For extended application work, keep gloves intact and replace them if damaged or contaminated. - **Eye protection:** Safety glasses with side shields provide minimum protection. For overhead work or where splashing is possible, chemical goggles or a face shield offer better coverage. - **Clothing:** Overalls or long sleeves protect skin from incidental contact. Contaminated clothing must not leave the workplace (P272) and must be removed and washed before reuse (P362+P364) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). - **Safety shoes:** Recommended for first aiders and applicators in construction environments (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). **Safe handling practices:** Avoid breathing any dust, fume, gas, mist, vapours, or spray generated during application (P261) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). While silicone sealants have low vapour pressure overall, cutting cartridge nozzles or applying in confined spaces can generate airborne particles or vapours. Wash hands, face, and all exposed skin thoroughly after handling (P264) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), especially before eating, drinking, smoking, or using the toilet, to prevent incidental ingestion or transfer to sensitive areas. Keep the product out of reach of children (P102) and ensure all users read and follow all instructions carefully (P103) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). **First aid procedures:** If poisoning occurs, contact a doctor or Poisons Information Centre immediately (Australia: 131 126, New Zealand: 0800 764 766) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). For skin contact where swelling, redness, blistering, or irritation occurs, remove contaminated clothing and flush skin and hair with running water, then seek medical assistance (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). If a skin rash develops, get medical advice (P333+P313) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). Note that effects may be delayed (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf), so monitor exposed skin for hours after contact. For eye contact, hold eyelids apart and flush eyes continuously with running water for at least 15 minutes, or until advised to stop by a Poisons Information Centre or doctor, then get to medical care (P305+P351+P338) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). Remove contact lenses if present and easy to do (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). If eye irritation persists after irrigation, seek medical advice (P337+P313) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). If swallowed, rinse mouth with water but do not induce vomiting (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). Give a glass of water to drink. Never give anything by mouth to an unconscious person. If vomiting occurs naturally, give further water and seek medical advice (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). For inhalation exposure, remove the person from the area without putting yourself at risk, remove contaminated clothing, loosen remaining clothing, allow the patient to assume the most comfortable position, keep warm and at rest until fully recovered, and seek medical advice if effects persist (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). ## Storage & handling **Storage requirements:** Store Selleys 635 in cool, dry conditions away from direct sunlight and heat sources. The UV stabilisers protect the cured product from sunlight but are not designed to protect uncured material inside transparent cartridges. Store cartridges upright to prevent filler settling and maintain consistent product performance. Keep caps and seals in place to stop moisture ingress; moisture contact starts the curing process inside the cartridge. Keep containers closed when not in use and store the product where children cannot access it (P102) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). **Disposal:** Dispose of contents and containers in accordance with local, regional, national, and international regulations (P501) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). For Australia and New Zealand, that means: - Fully dispensed empty cartridges with minimal residual can generally go to normal waste if local council regulations allow - Partially used cartridges must not go to household waste; contact local waste management authorities for hazardous household waste collection programmes - Commercial quantities require disposal through licensed waste contractors - Never pour uncured sealant down drains or into waterways **Spill management:** For small spills, wear protective equipment to prevent skin and eye contamination and avoid inhaling vapours or dust (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). Wipe up material with absorbent materials such as clean rags or paper towels, then collect and seal in properly labelled containers or drums (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). Uncured silicone lifts from skin with dry paper towels followed by soap and water. From hard surfaces, wipe up immediately before curing begins. Once partially cured, mechanical removal or solvent cleaners designed for silicone removal get the job done. ## Troubleshooting common issues **Poor adhesion or bond failure:** If the cured sealant pulls away from substrate surfaces, inadequate surface preparation is almost always the cause. Oil, moisture, dust, or old sealant residues block proper bonding. The fix: remove the failed sealant completely, clean substrates thoroughly with appropriate solvents, confirm surfaces are completely dry, and reapply. Three-sided adhesion also causes premature failure. When sealant bonds to the base of a deep joint as well as both sides, the stress on the sealant during joint movement increases substantially. Use backer rod or bond breaker tape at the joint base to prevent base adhesion and ensure the sealant works as designed. **Slow or incomplete cure:** If the sealant stays tacky or soft for an extended period, moisture availability is most likely the issue. Very dry climates, sealed joints with minimal exposed surface area, or cold temperatures can all slow cure significantly. Ensure adequate ventilation to supply atmospheric moisture, avoid application in very cold conditions, and allow extra cure time for deep or narrow joints. Chemical contamination or oil residues on surfaces can also inhibit cure. Clean surfaces thoroughly before application and keep incompatible materials away from the joint during cure. **Discolouration or yellowing:** Clear silicone sealants can yellow over time if UV protection is overwhelmed by intense, prolonged UV exposure, or if the sealant contacts certain chemicals or exhaust gases. The UV stabilisers in Selleys 635 (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf) provide strong protection against normal outdoor exposure, but extreme conditions may cause gradual colour change. This is typically cosmetic and does not indicate any loss of sealing performance. **Skin irritation or allergic reaction:** If skin irritation, rash, or allergic symptoms develop during or after use, this signals sensitivity to one or more components (H317) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). Wash affected skin with plenty of water and soap (P302+P352) and get medical advice (P333+P313) (SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf). For future applications, use proper protective gloves and consider barrier creams on exposed skin. Anyone who develops sensitisation should avoid further contact with the product. **Sealant tears or splits:** If the cured sealant develops tears or splits, joint movement has exceeded the sealant's elongation capacity, or the joint was not designed for the expected movement range. Ensure joint width matches the expected movement. For high-movement applications, assess whether a product with higher movement capability is the right tool for the job. ## Expert application tips **Achieving professional-looking beads:** Consistent bead size and immediate tooling are what separate a professional finish from an amateur one. Cut the nozzle to match the joint width; the bead should slightly overfill the joint before tooling. Maintain steady, even trigger pressure while moving along the joint at a consistent speed. Hesitation creates bulges; rushing creates gaps. Tool the bead immediately after application while the sealant is still wet and workable. Dip your tooling implement, finger, spatula, or shaping tool, in soapy water before each stroke. Draw the tool along the joint in one smooth, continuous motion rather than short strokes, which leave ridges and irregularities. The soapy water lubricates the tool, stops sealant sticking, and leaves a smooth, slightly concave surface profile that sheds water effectively. **Masking for clean edges:** For the cleanest possible joints on high-visibility installations, apply painter's masking tape to both sides of the joint before sealant application. Position the tape edges to define the exact finished bead width. Apply and tool the sealant, then remove the tape immediately while the sealant is still wet. Waiting until the sealant skins over makes tape removal a struggle and risks pulling sealant away from the joint. The result is geometrically precise edges with no cleanup required. **Managing multiple substrate types:** When sealing joints between different materials, glass to tile, metal to timber, test adhesion on a small, inconspicuous area first. The multipurpose formulation bonds to most common building materials, but unusual substrates, coatings, or finishes may call for primers or alternative sealants. A test application also confirms that the neutral cure chemistry produces no unexpected reactions with specific substrate compositions. **Optimising cure in challenging conditions:** In very dry climates or during winter when indoor humidity drops, cure rates slow down. A light mist of water from a spray bottle over the tooled bead, without saturating it, provides additional moisture for the cure reaction. In cold conditions, store cartridges at room temperature before use to keep the sealant workable and improve flow. Avoid application when substrate temperatures drop below 5°C, as cure rate becomes impractically slow and adhesion can be compromised. **Extending cartridge life after opening:** Once the nozzle is cut and the seal is broken, atmospheric moisture starts curing sealant in the nozzle. For cartridges used over days or weeks, seal the nozzle by inserting a long screw or nail into the opening, or wrapping the nozzle tip tightly with plastic wrap secured with tape or a rubber band. This blocks air circulation and significantly extends storage life. Even well-sealed partial cartridges will eventually cure in the nozzle; expect to cut off and discard the cured section before each subsequent use. ## References - Source PDF: SELLEYS_635_MULTIPURPOSE_ELASTIC_SEALANT_CLEAR-AUS_GHS.pdf (canonical) --- ## Frequently Asked Questions What is the product name: Selleys 635 Multipurpose Elastic Sealant Clear What is the product code: 103355 What is the barcode: 9300697132956 What is the package size: 290mL cartridge What colour is the sealant after curing: Clear and transparent What type of chemistry does this sealant use: Neutral cure silicone Does this sealant release acetic acid during curing: No What does neutral cure release instead of acetic acid: Alcohol or oxime compounds Is this sealant suitable for use on mirrors: Yes Why is it safe for mirrors: Neutral cure prevents attack on silvered backing Is this sealant safe for natural stone: Yes Why is it safe for natural stone: No acetic acid released to etch the surface Is this sealant safe for copper fittings: Yes Is this sealant safe for brass fittings: Yes Is this sealant safe for zinc-galvanised steel: Yes Does the clear formulation stay transparent after curing: Yes Is this sealant elastic after curing: Yes Can the cured sealant accommodate joint movement: Yes Does the cured sealant crack under thermal expansion: No Is this product classified as hazardous: Yes, under Safe Work Australia GHS 7 What is the signal word on the hazard label: Warning What skin hazard classification applies: Skin Sensitisation Category 1 What eye hazard classification applies: Eye Damage/Irritation Category 2A What hazard code applies to skin sensitisation: H317 What hazard code applies to eye irritation: H319 Is this product classified as Dangerous Goods for transport: No Does this product require dangerous goods placarding for transport: No Does this product have a Hazchem Code: No Does this product have a Poisons Schedule designation: No Is this product combustible: Yes Is this product flammable: No, combustible but not flammable Can this product emit toxic fumes in a fire: Yes What extinguishing media is suitable for this product: Water fog, foam, dry chemical, or CO2 What gloves are recommended for use: Nitrile rubber gloves Is eye protection required when using this product: Yes What minimum eye protection is required: Safety glasses with side shields Is protective clothing required when handling this product: Yes Should contaminated clothing be removed before leaving the workplace: Yes Are safety shoes recommended for applicators: Yes What is the Australian Poisons Information Centre number: 131 126 What is the New Zealand Poisons Information Centre number: 0800 764 766 How long should eyes be flushed after contact: At least 15 minutes Should vomiting be induced if the product is swallowed: No What should be given if the product is swallowed: A glass of water to drink Can skin sensitisation effects be delayed: Yes What should be done if a skin rash develops: Seek medical advice What adhesion promoter is present in the formulation: 1-Propanamine, 3-(trimethoxysilyl)- What percentage is the amino-functional silane: 1–10% by weight What epoxy-functional silane is in the formulation: Silane, trimethoxy[3-(oxiranylmethoxy)propyl]- What percentage is the epoxy-functional silane: 1–10% by weight What crosslinker is used in the formulation: Trimethoxyvinylsilane What percentage is the crosslinker: 1–10% by weight Are UV stabilisers included in the formulation: Yes What type of UV stabilisers are used: Hindered amine light stabilisers (HALS) What UV absorber type is used: Hydroxyphenylbenzotriazole derivative What percentage are the HALS stabilisers present at: Less than 1% by weight What percentage is the UV absorber present at: Less than 1% by weight Does this sealant resist UV degradation: Yes Can this sealant yellow over time in extreme UV conditions: Yes, but typically cosmetic only Does yellowing indicate loss of sealing performance: No Is this sealant suitable for wet area applications: Yes Is this sealant suitable for sealing around bathtubs: Yes Is this sealant suitable for shower bases: Yes Is this sealant suitable for kitchen sinks: Yes Is this sealant suitable for glazing applications: Yes Does this sealant bond to glass: Yes Does this sealant bond to aluminium frames: Yes Does this sealant bond to PVC: Yes Does this sealant bond to timber: Yes Does this sealant bond to ceramic tiles: Yes Is a primer required for most applications: No Does this sealant work on joints between dissimilar materials: Yes Is this sealant suitable for expansion joints: Yes Is this sealant suitable for construction perimeter joints: Yes How does this sealant cure: By reaction with atmospheric humidity Does temperature affect cure rate: Yes Does humidity affect cure rate: Yes Does low humidity slow cure: Yes Does cold temperature slow cure: Yes What is the minimum recommended substrate temperature for application: 5°C How should surfaces be prepared before application: Clean, dry, and free from contaminants Should old silicone be removed before reapplication: Yes Does silicone bond reliably to aged silicone: No What solvents are suitable for cleaning non-porous surfaces: Methylated spirits or isopropyl alcohol What angle should the nozzle be cut at: 45 degrees What tool is used to apply the cartridge: Standard caulking gun Should the bead be tooled after application: Yes What lubricant is used when tooling the bead: Soapy water Does soapy water prevent sealant sticking to the tool: Yes What causes premature joint failure in deep joints: Three-sided adhesion How is three-sided adhesion prevented: Use backer rod or bond breaker tape at joint base What is the most common cause of poor adhesion: Inadequate surface preparation What causes slow or incomplete cure: Insufficient atmospheric moisture Can a light water mist help cure in dry conditions: Yes How should partial cartridges be stored after opening: Seal nozzle to block air circulation How should cartridges be stored: Upright in cool, dry conditions away from sunlight Should cartridge caps be kept in place during storage: Yes Why must uncured sealant be kept from moisture during storage: Moisture triggers curing inside the cartridge Can partially used cartridges go to household waste: No Where should partially used cartridges be disposed of: Via local hazardous household waste programmes Should uncured sealant be poured down drains: No How are small spills cleaned up: Wipe with absorbent materials like clean rags Can uncured silicone be removed from skin with soap and water: Yes What is the ideal joint depth relative to joint width: Approximately half the joint width --- --- ## Label facts summary > **Disclaimer:** All facts and statements below are general product information, not professional advice. Consult relevant experts for specific guidance. ### Verified label facts **Product identification** - Full product name: Selleys 635 Multipurpose Elastic Sealant Clear 290mL - Product code: 103355 - Barcode (GTIN): 9300697132956 - Package size: 290mL cartridge - Sealant type: Neutral cure silicone - Appearance after cure: Clear and transparent **Composition & ingredients** - 1-Propanamine, 3-(trimethoxysilyl)- (amino-functional silane / adhesion promoter): 1–10% by weight - Silane, trimethoxy[3-(oxiranylmethoxy)propyl]- (epoxy-functional silane): 1–10% by weight - Trimethoxyvinylsilane (crosslinker): 1–10% by weight - Bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (HALS UV stabiliser): <1% by weight - Methyl (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (HALS UV stabiliser): <1% by weight - Hydroxyphenylbenzotriazole derivative (UV absorber): <1% by weight - Remaining ingredients: Non-hazardous or below reporting limits **Regulatory & hazard classification** - Classified as hazardous under Safe Work Australia GHS 7 - Signal word: Warning - Skin Sensitisation — Category 1 (H317): May cause an allergic skin reaction - Eye Damage/Irritation — Category 2A (H319): Causes serious eye irritation - Not classified as Dangerous Goods (Australian Code for Transport of Dangerous Goods by Road & Rail) - Not classified as Dangerous Goods under New Zealand NZS5433 - No Hazchem Code assigned - No Poisons Schedule designation **Fire characteristics** - Classified as combustible; does not meet flammable classification criteria - May emit toxic fumes upon burning or decomposition - Suitable extinguishing media: Water fog, fine water spray, alcohol-resistant foam, standard foam, dry chemical powder, carbon dioxide **Required safety precautions (label mandated)** - Wear protective gloves, protective clothing, and eye/face protection (P280) - Recommended gloves: Nitrile rubber - Minimum eye protection: Safety glasses with side shields - Safety shoes recommended for applicators and first aiders - Contaminated clothing must not leave the workplace (P272); remove and wash before reuse (P362+P364) - Avoid breathing dust, fume, gas, mist, vapours, or spray (P261) - Wash hands and exposed skin thoroughly after handling (P264) - Keep out of reach of children (P102) - Read all instructions before use (P103) - Dispose of contents and container in accordance with local, regional, national, and international regulations (P501) **First aid (label mandated)** - Poisoning emergencies — Australia: 131 126 | New Zealand: 0800 764 766 - Skin contact with irritation/reaction: Remove contaminated clothing, flush with running water, seek medical advice (P302+P352, P333+P313); effects may be delayed - Eye contact: Flush continuously with running water for at least 15 minutes; remove contact lenses if present and easy to do; seek medical attention (P305+P351+P338, P337+P313) - Swallowed: Do not induce vomiting; rinse mouth with water; give a glass of water to drink; seek medical advice - Inhalation: Remove from area, loosen clothing, allow to rest; seek medical advice if effects persist **Cure mechanism** - Cures by reaction with atmospheric humidity - Cure rate is affected by temperature and relative humidity - Low humidity and cold temperatures slow cure - Minimum recommended substrate temperature for application: 5°C - Neutral cure: releases alcohol or oxime compounds (not acetic acid) during cure **Storage** - Store in cool, dry conditions away from direct sunlight and heat sources - Store cartridges upright - Keep caps and seals in place to prevent moisture ingress - Keep out of reach of children (P102) **Disposal** - Partially used cartridges: Do not dispose of in household waste; use local hazardous household waste collection programmes - Commercial quantities: Dispose via licensed waste contractors - Do not pour uncured sealant down drains or into waterways --- ### General product claims - Delivers reliable, elastic sealing performance across a wide range of building and construction applications - Engineered to bond to multiple substrate types without needing specialised variants for every material - Cured sealant stretches and compresses with joint movement, holding firm against thermal expansion, structural settlement, and vibration without cracking or losing adhesion - Clear formulation stays visually unobtrusive after curing; suitable where aesthetics matter - Neutral cure protects mirrors, natural stone, marble, copper, brass, zinc-galvanised steel, and electronic components from corrosion or acid etching - Multi-mechanism adhesion system allows sealing between dissimilar materials (e.g., glass to metal, PVC to timber) without primers in most applications - Dual UV protection system (HALS + benzotriazole absorber) maintains elasticity, adhesion, and clarity through extended outdoor exposure - Yellowing under extreme UV conditions is typically cosmetic and does not indicate loss of sealing performance - Suitable for sanitary and wet area sealing, glazing, general construction joints, and appliance/fixture installation - Moisture resistance prevents water ingress leading to substrate damage or mould growth behind sealed joints - Soapy water used during tooling prevents sealant from sticking to the tool and delivers a smooth, professional surface finish - Masking tape technique produces geometrically precise bead edges with no cleanup required - Light water mist over tooled bead can assist cure in very dry conditions - Sealing the nozzle after use significantly extends partial cartridge storage life ## Related Products & Brand Context The Selleys 635 Multipurpose Elastic Joint Sealant sits within the **Selleys** brand range, a well-established Australian adhesives and sealants manufacturer. Selleys is broadly known for construction and home-improvement bonding products, and the 635 fits squarely into their sealants line — specifically the multi-purpose sealant segment under the **Home & Garden > Adhesives & Sealants** category. The product's official listing on the Selleys website categorises it alongside other multi-purpose sealants, suggesting buyers looking at one product in that grouping are likely to encounter others with overlapping but distinct performance profiles. What sets the 635 apart within its category is its combination of low modulus formulation and advanced hybrid technology. Low modulus means the cured sealant remains highly flexible and can absorb joint movement without cracking — a characteristic that distinguishes it from standard, rigid construction adhesives or high-modulus sealants better suited to static joints. Its compliance with **Australian Standard AS 2329-1999** for construction adhesives and sealants further positions it as a product intended for verified, standards-backed performance in professional and trade contexts, not just casual DIY use. From a use-case adjacency perspective, someone reaching for the Selleys 635 is typically mid-project on a sealing or bonding task involving timber, concrete, or metal substrates. That workflow commonly calls for complementary products: surface preparation items such as primers or cleaners to ensure proper adhesion to non-porous surfaces, and application tools like a standard 290ml cartridge gun to dispense the paste-form sealant accurately. Once the sealant is fully cured, the product's paintable finish means it also sits upstream of any decorative top-coat products a buyer might need to complete the job. The 290ml cartridge format is a standard trade size, making the 635 compatible with most conventional caulking guns readily available through hardware and building-supply retailers. Buyers comparing it to other Selleys sealant options should note that its hybrid chemistry and UV, weather, and moisture resistance make it particularly suited to external or exposed joints where silicone-only or acrylic-only products may fall short.