Silicone sealant “Neutral”

Neutral silicone sealant by Lacrysil is a 100 % solvent-free silicone with a neutral (oxime) cure. Use it to seal joints in building structures, expansion joints, glazing units in window frames, and joints between glass, metal and stone panels, indoors and out. Available in white and clear.

Neutral, not acetic

Acetic silicones release acetic acid as they cure: they smell sharp and can attack metal. Neutral silicone cures from air moisture without acid, so it does not corrode metal parts, suits aluminium and galvanized profiles, and has only a faint smell during work.

Smooth surfaces without primer

The sealant has improved adhesion to non-porous surfaces such as glass, metal, ceramics and glazed tile: degrease them and no primer is needed. Porous substrates such as concrete, plaster or brick should first be treated with Lacrysil primer concentrate diluted 1:10.

A joint for outdoors and moisture

The cured bead is elastic, with movement capability of at least 20 %, so it absorbs thermal movement of structures. It works from -40 to +100 °C, does not break down under UV, is water- and vapour-tight, and withstands household cleaners. It does not support mould or fungus.

White or clear

The joint performs the same in both; only colour and pack size differ. Choose white for white window frames, sills, tile and white panels where the bead should match the surface. Choose clear for glass, glazing units, stone, marble and coloured surfaces where the bead should be nearly invisible.

Specifications

• Application temperature: +5…+40 °C

• Skin time: 15–25 minutes (at +23 °C, 50 % humidity)

• Full cure: 24–48 hours, depending on bead size and conditions

• Recommended joint width: up to 6 mm

• Coverage: at least 12 m of 6×6 mm bead per cartridge

• Density: white 1.4–1.45 g/cm³, clear 0.9–1.03 g/cm³

How to apply

1. Clean surfaces of dust, rust and old paint and degrease them: glass and metal with ethanol, plastic with detergent. Prime porous substrates.

2. Mask the joint edges with tape.

3. Cut the cartridge neck above the thread, screw on the nozzle cut at 45°, and load the cartridge into a gun.

4. Apply an even, continuous bead.

5. Tool the joint straight away with a spatula dipped in soapy water, then remove the tape.

If you pause, cap the nozzle at once. Remove fresh sealant with ethanol or acetone; cured sealant comes off mechanically only.

Limits

The sealant cannot be painted or tinted. Do not apply it to bitumen or resinous materials or to plastics that release plasticizers. Do not use it in aquariums or where it may contact food directly. Protect ferrous metal against corrosion before sealing. A small amount of methanol is released during curing, so ventilate indoor spaces. May cause an allergic skin reaction: wear gloves.

Packaging and storage

Threaded cartridge with nozzle and protective cap: white 400 g net, clear 280 g net. Store at +5…+35 °C, do not freeze. Shelf life 18 months.

FAQ

How is neutral silicone different from regular silicone? Regular (acetic) silicone releases acetic acid as it cures. Neutral silicone cures without acid, does not attack metal and has almost no smell.

How many cartridges do I need? One cartridge gives at least 12 m of 6×6 mm bead. A 1.3×1.4 m window perimeter (about 5.4 m) needs one cartridge with room to spare.

Can the joint be painted? No, silicone cannot be painted. If the joint must be painted, use an acrylic sealant.

When is the joint ready? It skins over in 15–25 minutes and fully cures in 24–48 hours.