Sikaflex®-403 Tank & Silo

• Assessment of the joint sealant DIN EN 14188-2:2005-03, Sikaflex-403 Tank & Silo, SKZ, No. 224872/22.

• Foodstuff and migration behaviour EN 1186, EN 13130, CEN/TS 14234, ISEGA, No. 62008 U 24.

• General building regulations, DIBt, No. Z-74.62-212.

• UKCA and CE marking and declaration of performance based on EN 15651-4:2012 Sealants for non-structural use in joints in buildings and pedestrian walkways — Part 4: Sealants for pedestrian walkways.

Polyurethane

15 months from date of production

The Product must be stored in original, unopened and undamaged sealed packaging in dry conditions at temperatures between +5 °C and +25 °C. Always refer to the packaging.

Refer to the current Safety Data Sheet for information on safe handling and storage.

IMPORTANT

Depolymerisation due to chemical attack

The Product is not fully chemically resistant until the Product has fully cured. Moreover, chemical resistance depends on the chemicals, their concentration and their temperature. Exceeding the stated performance limits could cause depolymerisation of the sealant.

1. Analyze the content, exposure time and temperature of the chemicals.
2. Design the joints for the intended and foreseeable conditions.

Sikaflex®-403 Tank & Silo is resistant to:

• Water

• Sea water

• Liquid manure

• Silage liquid

• Dilute alkali

• Neutral water-based dispersed detergents or cleaners

• Domestic and municipal sewage

Sikaflex®-403 Tank & Silo is not resistant to:

• Concentrated organic and inorganic acids

• Organic solvents

• Chlorinated or aromatic hydrocarbons

IMPORTANT

Depolymerisation due to exceeded service temperature

In any process system, service temperatures affect the aggressiveness of the chemical mixture. Exceeding the stated performance limits could cause depolymerisation of the sealant.

1. During specification, analyze the content of the chemicals to establish their behavior at temperature, and to define the continuous maximum service temperature.

Service temperature range in a dry condition.

Maximum service temperature in a wet condition.

Refer to all relevant local construction guidelines and regulations. The sealant must be specified and included in the design of the containment system.

Reference must be made to the following document: Design guideline: Dimensioning of construction joints.

Use closed cell, polyethylene foam backing rod.

Poor adhesion due to inadequate surface preparation

Note: Primers are adhesion promoters. Primers cannot replace proper surface preparation and surface cleaning.

1. Do not use primers for improving poorly prepared or poorly cleaned joint surfaces.

The substrate must be sound, clean, dry and free of all contaminants such as dirt, oil, grease, cement laitance, old sealants and poorly bonded coatings which could affect adhesion of the sealant.

The substrate must be of sufficient strength to cope with the stresses induced by the sealant during movement.

1. Use techniques such as wire brushing, grinding, grit blasting or other suitable mechanical tools to remove all weak substrate material.
2. Repair all damaged joint edges with suitable Sika® repair products.
3. Completely remove all dust, loose and friable material from all surfaces before application of any activators, primers or sealant.
4. Where joints in the substrate are saw-cut, flush away all slurry material and allow joint surfaces to dry.

The following priming and pretreatment procedures must be followed to ensure optimum adhesion and joint durability for critical, high-performance applications such as joints with chemical load and permanent immersion. Consult the tank manufacturer for information on preparation and priming.

NON-POROUS SUBSTRATES

Enamelled steel

1. Pretreat the surface with Sika® Aktivator-205 applied with a clean cloth.

Aluminum, anodised aluminum, stainless steel, galvanised steel, epoxy and fusion-bonded epoxy, powder-coated metals, or glazed tiles.

1. Pretreat the surface with Sika® Aktivator-205 applied with a clean cloth.
2. Alternatively, prime the surface with Sika® Primer-3 N applied with a brush.

Other metals, such as copper, brass and titanium zinc.

1. Pretreat the surface with Sika® Aktivator-205 applied with a clean cloth.
2. Wait until the flash-off time is over.
3. Prime the surface with Sika® Primer-3 N or Sika® Primer-115 applied with a brush.

PVC substrates

1. Prime the surface with Sika® Primer-215 applied with a brush.

POROUS SUBSTRATES

Concrete, aerated concrete and cement-based renders, mortars and bricks

1. Prime the surface with Sika® Primer-3 N or Sika® Primer-115 applied with a brush.

For more details of the primer or pretreatment products, refer to the corresponding Product Data Sheet. Contact Sika® Technical Services for additional information.

IMPORTANT

Strictly follow installation procedures

Strictly follow installation procedures as defined in Method Statements, application manuals and working instructions which must always be adjusted to the actual site conditions.

IMPORTANT

Application by trained personnel

The application of this Product must only be carried out by an applicator that is trained or approved by Sika®. The applicator must also be experienced in this type of application.

IMPORTANT

Allowing insufficient curing time

Putting the Product into service too early can result in a reduction of the long-term stability of sealed sections.

1. Allow the Product to fully cure before it is exposed to mechanical or chemical stress.

IMPORTANT

Damage due to corrosion

Corrosion protection is dependent on the thickness of the sealant layer. For butt or lap joints the Product provides effective protection at an application thickness of ≥ 8 mm.

IMPORTANT

Resistance to chlorine

The Product is resistant to chlorine for tank disinfection and dosing purposes only.

1. Contact the tank supplier for guidelines and detailed conditions on dosing and disinfection.

IMPORTANT

Degradation of sealant due to substrates leaching oil, plasticisers, or solvents

Bitumen, natural rubber or EPDM rubber can leach oils, plasticisers, or solvents that can degrade the sealant and cause the Product to become tacky.

1. Do not use the Product on building materials which leach oils, plasticisers, or solvents.

IMPORTANT

Staining on natural stone substrates due to plasticiser migration

Staining from plasticiser migration may occur when used on cast, reconstituted or natural stone such as granite, marble or limestone substrates.

1. Do not use on natural stone substrates

IMPORTANT

Degradation of sealant due to chemical attack

1. Do not use the Product to seal joints in and around swimming pools containing water treatment agents such as chlorine.

IMPORTANT

Insufficient curing due to exposure to alcohol

Exposure to alcohol during curing may interfere with the curing reaction and cause the Product to remain soft or become tacky.

1. Do not expose the Product to alcohol-containing products during the curing period.

1. Apply masking tape where neat or exact joint lines are required.
2. After the required substrate preparation, insert a backing rod to the required depth.
3. Prime the joint surfaces as recommended in substrate preparation. Note Avoid excessive application of the primer.
4. Open the seal on the top of the cartridge or open the end of the foil pack.
5. Fit the nozzle and cut it to the desired bead size.
6. Insert the Product into the application gun.
7. Apply the Product into the joint. Note Avoid air entrapment. Make sure that the Product comes into full contact with the adhesion area of the joint.
8. IMPORTANT Do not use tooling products containing solvents. As soon as possible after application, tool the Product firmly against the joint sides to ensure adequate adhesion and a smooth finish. Use a compatible tooling agent such as Sika® Tooling Agent N to smooth the joint surface.
9. Remove the masking tape within the skin formation time of the Product.

For lap joints such as in enameled steel containers consult the tank manufacturer for specific application advice.

OVERPAINTING THE SEALANT

IMPORTANT

Tacky paint due to plasticiser migration

Paints and sealants or adhesives may contain plasticizers and other substances that migrate and can cause the painted surface to become tacky.

IMPORTANT

Cracking paint due to joint movement

Rigid paint applied on top of a sealant or flexible adhesive may crack when used on joints subject to movement.

The Product can be overpainted with most conventional paint coating systems.

1. Allow the Product to fully cure before overpainting.
2. Before overpainting, carry out preliminary trials to test compatibility of the paint or coating system with the Product in accordance with ISO/TR 20436:2017 – Buildings and civil engineering works — Sealants — Paintability and paint compatibility of sealants.

Colour variation

Note: Colour variation may occur especially with white or other light colour shades. This effect is purely aesthetic and does not adversely influence the technical performance or durability of the Product.

Clean all tools and application equipment immediately after use with Sika® Thinner C. Sika® Wonder Wipes are specially formulated to clean wet and semi-cured sealant from hands, tools and surfaces. Once cured, hardened material can only be removed mechanically.