Aquarium silicone sealant suitable for fish tanks and heavy duty marine work as it contains NO fungicides.




Features & benefits

Bostik Marine is a clear, one part acetoxy curing high quality silicone sealant that provides a permanent flexible, durable, watertight seal when building fish tanks and aquariums. Excellent for heavy duty marine work. Ideal for general purpose sealing, waterproofing and weatherproofing requirements in and around the house when doing DIY projects. The sealant is extremely resistant to UV, weathering, ageing and water, and offers excellent chemical resistance and is unaffected by alcohols, diluted acids and alkalis, soap and household detergents. The sealant remains flexible over a wide range of temperatures from -40°C to 100°C. It also performs as an excellent adhesive on non-porous surfaces where an elastic gap-filling bond is required.

Not suitable for alkaline surfaces such as concrete, fibrous cement, asbestos, plaster and marble. Not suitable for some metals i.e. mild steel, lead, copper, tin, galvanized iron, brass or zinc as it may cause corrosion. May become discoloured in contact with some organic elastomers, which tend to bleed oil or solvents into the silicone, e.g. EPDM, APTK, Neoprene and Bituminous surfaces. It should not be used on the back of mirrors, as it will de-silver the mirror backing, affecting the front appearance of the mirror. Not suitable for contact with natural stone i.e. marble, granite, quartzite as it may discolour the surfaces. Will not adhere to some plastics such as polyethylene, polypropylene and Teflon. Do not apply sealant when relative humidity is below 10% - cure rate will be affected.

Not suitable where mould-resistance is required e.g. sealing of showers, basins and baths.

Does not contain a fungicide which may be harmful to aquarium fish.

Not paintable.

Downloads & resources

Bostik DIY South Africa Seal - Marine Silicone Sealant Technical Data Sheet (300.07 KB)

Bostik DIY South Africa Seal - Marine Silicone Sealant Safety Data Sheet (141.07 KB)

How to use

Ensure surfaces are clean, dry and free of loose materials, dust, grease, rust and other contaminants. Use masking tape to get a clean, even sealant line and to eliminate cleaning difficulties on porous surfaces. Remove tape before sealant skins.

90ml Tube 

  • Remove the cap and pierce seal with reverse side of cap.
  • Cut the nozzle to desired bead size and screw onto tube.
  • Apply silicone at a slight angle in a continuous bead to the prepared joint.
  • After use, remove the nozzle, wipe clear and replace the cap firmly.

280ml Cartridge 

  • Cut the tip off the cartridge and screw on the nozzle.
  • Cut the tip of the nozzle at an angle to achieve the desired bead size.
  • Apply with a caulking gun in a continuous bead to the prepared joint.
  • Remove unwanted silicone immediately.
  • Smooth down after application within 3-5 min before skin formation occurs, by using a flat or rounded tool. Sealant dries to touch in approximately 45 minutes and reaches full cure after approximately 24 hours.


How do I store my silicone?

To maximize the shelf life of an opened silicone cartridge, we recommend that the nozzle be removed and a piece of plastic placed over the cartridge tip after which the nozzle must be screwed back on. A large screw inserted into the nozzle tip also helps to extend the life. Store in a cool environment.

How do I remove cured silicone?

Cured sealant must be removed mechanically with a sharp knife or chemically with Bostik Silicone Stripper. Always test on a small surface first.

Which sealant is the right one for my application?

Stuck in a rut and not sure which sealant is suitable for your application? Call our Sticky Questions Helpline during office hours on 0800 222 400 for technical support.

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