Pattex SL212 General Purpose Silicone

This is the cartridge the trade here buys as “Pattex Smart”, and the pack settles what it actually is: Pattex SL212 — GENERAL PURPOSE — ACETIC SILICONE, 280 mL, “Quality for Professionals”, made in Türkiye and imported by Henkel Kenya. Acetic means acetoxy cure — it is the fast-curing, hard-working general-purpose silicone, not a neutral-cure one, and that is the single fact that decides whether it suits your job.

Henkel publishes it for sealing joints in sanitary and construction work, on tiles, ceramics, glass, brick, lacquered and anodised aluminium, painted metals and wood. Glazing, window and door perimeters, kitchen and bathroom joints, and general non-porous joint sealing. It is mildew resistant and waterproof, and Henkel rates it from −30 °C to +120 °C. The pack's own icons read multimaterials, water resistant and UV resistant. Skin forms in about 15 minutes, so tool the bead promptly.

Sold by the carton of 24 in three colours. Before you order, two limits that matter: an acetoxy silicone releases acetic acid as it cures, so Henkel says do not use it against lead, copper, zinc or iron, and not on mirrors or aquaria — use a neutral-cure sealant for those. It is also not paintable and not for permanent water immersion or drinking-water contact. The pack tells you to use it only outdoors or in a well-ventilated area, and to keep it off eyes, skin and clothing. The cartridge photographs are Henkel's own front-of-pack shots, one for each colour, and the last picture is the back of a cartridge so you can read the instructions and the warning before you buy.

Specifications

Henkel, Pattex SL212 General Purpose technical data sheet, and the pack.

• Article numbers (IDH): white 2637448 · transparent 2637449 · black 2500095
• Chemistry: acetoxy silicone, acetic-acid-releasing cure. Not a neutral cure
• Pack: 280 ml cartridge
• Skin formation: 15 minutes at 23 °C, 50% relative humidity
• Cure rate: 2 mm per 24 hours (23 °C, 50% r.h., 20 × 10 mm bead)
• Elongation at break: 110%
• Modulus at 100% elongation: 0.35 N/mm²
• Hardness: Shore A 20
• Service temperature: −30 °C to +120 °C
• Water resistance: waterproof; resistant to water, ozone and ultraviolet radiation. Not for permanent immersion and not for drinking-water contact
• Mould: mildew resistant
• Over-paintable: no
• Storage: the pack says keep dry between +5 °C and +25 °C; shelf life 18 months from manufacture
• Movement accommodation, coverage: not published by Henkel

Where not to use it

• Against corrosive metal surfaces — lead, copper, zinc, iron — because the cure releases acetic acid.
• Mirrors and aquaria.
• Joints under permanent water immersion, and anything in contact with drinking water.
• Bituminous substrates, natural rubber, chloroprene and EPDM.
• The pack's own list begins “not suitable for PE, PP, PTFE, PMMA…” and continues around the cartridge, so read it on the pack before you commit. PMMA is acrylic, which rules out acrylic glazing and most shower screens.

The pack carries a warning that it contains an isothiazolinone biocide, which may produce an allergic reaction, and instructs you to use it only outdoors or in a well-ventilated area and to keep it off eyes, skin and clothing. Ask us for the safety data sheet before first use on site.