Sika Sikagard®-694 F(I)
The epoxy putty that keeps working when the substrate is wet, damp, or fully underwater.
What is it?
A solvent-free, two-component epoxy resin putty (Part A + Part B, 1:1 by weight) engineered to be moisture-insensitive, meaning it cures and bonds reliably even on damp concrete or fully submerged surfaces where ordinary epoxies fail.
Where is it used?
Underwater and below-waterline repairs on dams, jetties, breakwaters, water tanks, STP/ETP structures, swimming pools, wave pools and water-slide flumes; also general crack sealing on concrete, metal and wooden surfaces above water.
Why use it?
Most site cracks, joints and penetrations are damp or actively seeping by the time a repair crew reaches them, and conventional epoxy putties either refuse to bond or lose strength on wet substrate. Sikagard-694 F(I) is formulated specifically to bond on damp, dry and underwater surfaces alike, stop water ingress immediately, and resist chloride/saline attack — useful anywhere corrosion of embedded steel is a concern.
How is it applied?
Hand-mixed 1:1 by weight using a slow-speed drill and spindle for at least 3-4 minutes until uniform grey, then applied within the ~50-minute pot life using gloved hands, a spatula or a trowel, working it firmly into the prepared crack, joint, penetration or packer location; the surface can be smoothened with wet gloves before it sets.
About Sika Sikagard®-694 F(I)
Sikagard-694 F(I) sits in a fairly narrow but genuinely useful niche: it is one of the few epoxy putties Sika India sells that is explicitly rated for underwater and damp-substrate application rather than just tolerant of a slightly moist surface. Most two-part epoxy repair putties in the market are dry-substrate products — moisture at the bond line interferes with the epoxy-amine cure and adhesion drops sharply, which is exactly the situation site engineers run into on dam galleries, sewage treatment tanks, water-retaining structures and swimming pool shells that can rarely be taken fully dry before a repair. Sikagard-694 F(I) is built around a solvent-free epoxy resin base specifically to displace surface moisture and cure properly on wet or submerged concrete, metal and timber, which is why Sika positions it for jobs like sealing cracks below the waterline on dams and jetties, plugging leaks around drainage outlets and pipe penetrations, and fixing the injection packers and PVC/metal nozzles used in crack-injection grouting work.
On Indian sites we most often see it specified for exactly those packer-fixing and pre-injection sealing jobs — it holds packers firmly against hydrostatic pressure while low-viscosity injection resin is pumped into the crack behind it — as well as for patching leak points in overhead and underground water tanks, STP/ETP chambers, basement retaining walls with active seepage, and the occasional waterpark slide or wave-pool repair where the structure cannot be drained for the repair window available. It is not a structural repair mortar for large-volume patching or a substitute for a proper waterproofing membrane; treat it as a precision sealing and fixing putty for cracks, joints and penetrations where the substrate is wet, and pair it with Sika’s crack-injection resins or a membrane system for the larger waterproofing scope.
The technical insight
The property that actually matters on a damp or submerged jobsite is tensile adhesion strength under wet conditions, not the dry-lab number most epoxy putty datasheets lead with. Sikagard-694 F(I) is rated at ≥10 N/mm² tensile adhesion strength to ASTM C 882 — a standard specifically written to test epoxy bonding to concrete — which is the datasheet’s way of confirming the moisture-insensitive claim rather than just asserting it. The 1:1 mix ratio by weight (rather than the more finicky volume ratios common on some epoxy systems) and the roughly 50-minute pot life at 30°C give site crews a workable window to mix, carry to a submerged or hard-to-reach crack, and tool it in before it starts to kick off — important because unlike a coating, this putty is worked in by hand and needs to stay pliable long enough to be pressed fully into an irregular crack or around a packer.
Where it is used
- Sealing cracks below the waterline on dams, jetties, breakwaters and other marine/hydraulic structures
- Plugging leaks around drainage outlets, pipe penetrations and sleeve openings as part of a waterproofing scope
- Fixing metal or PVC injection packers and nozzles ahead of crack-injection grouting works
- Sealing cracks in concrete, metal and wooden surfaces in both wet and dry conditions
- Repair of swimming pools, wave pools and waterpark slide flumes without full structure drain-down
- Patching leak points in overhead/underground water tanks, STP and ETP chambers
- Sealing basement retaining walls and lift pits with active seepage
- Bedding and fixing hardware or fittings on damp substrates where a dry-cure epoxy would fail to bond
Key advantages
- Bonds and cures reliably on damp, wet and fully submerged substrates, not just “moisture-tolerant” dry concrete
- Stops active water ingress at the point of application rather than needing the leak stopped first
- Excellent resistance to saline/marine environments, useful on coastal and hydraulic structures
- Helps eliminate corrosion of embedded steel by sealing the crack path chlorides would otherwise travel through
- Simple 1:1 by-weight mix ratio reduces batching errors on site compared to volume-ratio epoxies
- Hand-applicable with basic tools (spatula, trowel, gloved hand) — no specialised injection equipment needed for the sealing step itself
- Solvent-free formulation is safer to apply in confined, poorly ventilated spaces like tanks and pits
- Good impact and mechanical strength once cured, holding up to hydrostatic pressure behind packers
Limitations & considerations
- Not a structural repair mortar — not intended for large-volume patching, spalled concrete restoration or load-bearing repair
- Application temperature is limited to +10°C to +40°C per the datasheet’s stated limitation, despite the wider +5°C to +45°C ambient/substrate range also quoted, so peak Indian summer surface temperatures need shading or early-morning application
- Pot life of roughly 50 minutes at 30°C shortens further in peak summer, so batch sizes must be kept small on hot sites
- Colour is limited to grey once mixed (white Part A, black Part B) — not intended as an exposed cosmetic finish
- Hand/trowel application only — not pumpable or sprayable, so unsuitable for sealing long crack runs quickly
- Needs a reasonably sound, cleaned substrate free of laitance, oil, grease and marine growth; it does not fix an unstable or actively spalling substrate on its own
Selection & best practice
Prepare the crack or penetration mechanically (wire brush, grinding, or scraping) to remove laitance, oil, grease and marine growth even if the surface is wet or submerged — the epoxy needs mechanical key, not just chemical bond. Mix only what will be used within the pot life (roughly 50 minutes at 30°C, less in peak summer), using a slow-speed drill (max. 600 rpm) for at least 3-4 minutes until the colour is a uniform grey with no streaking, then transfer to a clean container and mix for a further minute to minimise trapped air. Press the putty firmly into the crack or around the packer with gloved hands or a spatula, working from one end to avoid trapping voids, and smoothen the surface with wet gloves before it sets. Clean tools immediately with Sika Colma Cleaner or an equivalent solvent, since cured material can only be removed mechanically. For long crack runs or where structural gap-filling is also needed, pair Sikagard-694 F(I) as the packer-fixing and edge-sealing putty with a proper Sika crack-injection resin system rather than relying on it as the sole repair.
Specifications
| Chemical base | Epoxy resin (solvent-free) |
| Mixing ratio | 1 : 1 by weight (Part A : Part B) |
| Density (mixed) | ~1.55 (±0.05) kg/litre at +30°C |
| Tensile adhesion strength | ≥10 N/mm² (per ASTM C 882) |
| Pot life | ~50 minutes for a 100 g mass at +30°C |
| Application temperature | +10°C to +40°C (limitation); ambient/substrate range quoted +5°C to +45°C |
| Shelf life | 12 months from date of production, stored +5°C to +30°C |
| Standard conformance | ASTM C 882 |
| Packaging | Part A 4 kg + Part B 4 kg pre-batched (8 kg set); colours white / black, mixed grey |
Industry use cases
Dams, jetties & marine structures
Sealing cracks below the waterline and fixing injection packers on hydraulic structures exposed to continuous submersion and saline attack.
Water & wastewater infrastructure
Plugging active leaks and penetrations in overhead/underground water tanks, STP and ETP chambers without draining the structure.
Basements & below-grade structures
Sealing seeping cracks and construction joints in basement retaining walls and lift pits where the surface cannot be dried before repair.
Waterparks & swimming pools
Patching cracks and leaks in pool shells, wave pools and slide flumes during short shutdown windows.
Crack-injection grouting works
Fixing metal or PVC packers and surface-sealing the crack line ahead of low-viscosity resin injection.
Frequently asked questions
Can Sikagard-694 F(I) really be applied underwater, or does the surface just need to be damp?
How is it different from a normal crack-injection epoxy resin?
What is the pack size and how is it mixed?
Does it need the leak to be stopped before application?
Can it be used for large spalled or structurally damaged concrete areas?
Does Space Arc supply this ready-to-use in Delhi NCR and pan-India?
How we position Sika Sikagard®-694 F(I)
Within Sika’s own range, Sikagard-694 F(I) works alongside Sika’s crack-injection resins (pumped into the crack once it is sealed and packered) and the Sikadur family of structural epoxy adhesives (for bonding and structural repair) — it fills the specific gap of a hand-applied, moisture-insensitive putty for sealing and packer-fixing where the substrate is wet or submerged, rather than competing with either. It should not be confused with Sika’s broader volumetric repair mortar range (Sika MonoTop, Sikacrete), which targets dry or lightly damp substrates rather than underwater work. We could not confirm a Fosroc product genuinely built and rated for this same underwater/moisture-insensitive niche in current distribution, so specifiers comparing brands for below-waterline crack sealing and packer fixing are best served staying within the Sika range rather than substituting a general-purpose epoxy putty that isn’t rated for submerged use.
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