Sika Sikadur-32 LP IN
A solvent-free, two-component epoxy structural bonding agent engineered with a long pot life for warm and high-temperature Indian conditions, joining fresh concrete to hardened concrete and a wide range of materials.
What is it?
A two-component, solvent-free epoxy structural bonding agent (resin plus hardener) formulated with an extended pot life so it stays workable on hot sites. It complies with ASTM C881-78 Type II, Grade 2, Class B+C.
Where is it used?
Repair and new-build works where fresh concrete, mortar, stone, steel, timber or fibreglass must be structurally bonded to prepared hardened concrete, especially in high-ambient-temperature regions across Delhi NCR and Pan-India.
Why use it?
It grips damp or dry substrates without a separate primer, holds workability beyond four hours at +30 degrees C, and develops high early and ultimate strength, so crews get a dependable structural bond even when temperatures climb.
How is it applied?
Mix Part A to Part B at 2:1 by weight for four minutes, then brush, roller, trowel or spray onto both prepared faces. Place fresh concrete while the film is still tacky, or bond the second element within the open time.
About Sika Sikadur-32 LP IN
Sikadur-32 LP IN belongs to Sika’s long-established Sikadur family of epoxy adhesives, and the “LP” tag is the important part of its name: it stands for long pot life. On an Indian site in May or June, a standard epoxy bonding coat can go off in the pail before a crew has finished spreading it, forcing repeated small batches and wasted material. This grade is reformulated so the mixed adhesive stays usable for more than four hours at +30 degrees C, with an open time beyond seven hours, which is exactly the headroom a contractor needs when working through the afternoon heat or across a large pour joint.
Beyond the working time, it is a genuine structural adhesive rather than a simple primer. It is solvent-free and moisture tolerant, so it bonds wet or dry materials onto damp or dry substrates and cures without shrinkage to a hard, impermeable film. The concrete-grey Part A and dark-grey Part B are deliberately different colours so the applicator can see at a glance when mixing is complete. Because the two coats it joins carry load, Sika restricts it to experienced professionals and expects the bond to be designed by a structural engineer, not treated as a general-purpose glue.
The technical insight
The chemistry that makes this grade “low pot life risk” in the heat is a hardener system chosen to slow the exotherm. Every epoxy cures through an exothermic reaction, and heat accelerates it, so on a hot day a fast epoxy heats itself and races to gel. Sikadur-32 LP IN uses a slower reaction profile that resists this runaway, which is why the pot life is quoted at more than four hours at +30 degrees C rather than the tens of minutes typical of a rapid epoxy. The bond itself works because the low-viscosity mixed resin wets out and penetrates the open, mechanically roughened surface pores of the substrate, then polymerises into a continuous rigid network keyed into both faces. That keying is why surface preparation matters so much: an abraded, dust-free, matt-damp-but-not-wet profile gives the resin somewhere to grip, and the tensile adhesion of at least 10 MPa after moist curing reflects a bond stronger than the parent concrete, so failure is pushed into the substrate rather than the glue line.
Where it is used
- Bonding freshly placed concrete to prepared hardened concrete at construction joints and stop-ends
- Priming and bonding coat between old concrete and repair mortars, toppings or overlays
- Structurally bonding steel plates, sections and inserts onto concrete
- Fixing hard natural stone, ceramics and fibre-cement to concrete substrates
- Adhering timber, polyester, fibreglass and cured epoxy elements to concrete
- Bonding brick, block, masonry and render in structural repair works
- Connecting industrial floor slabs and plinths in warm plant environments
- Structural joining tasks on hot summer sites where standard epoxies gel too fast
Key advantages
- Long pot life of over 4 hours at +30 degrees C keeps the mix workable through hot Indian afternoons
- Open time beyond 7 hours gives generous latitude to place the second element
- Moisture tolerant, so it bonds to damp or dry concrete without waiting for a bone-dry substrate
- No separate primer required, cutting one full step and one product from the sequence
- Solvent-free and low odour, suitable for enclosed and poorly ventilated areas
- High early and ultimate strength, with compressive strength of at least 55 MPa at 7 days
- Contrasting A and B colours give a clear visual check that mixing is complete
- Cures without shrinkage to an impermeable film, resisting liquid and water-vapour ingress
Limitations & considerations
- Maximum layer thickness is about 1 mm; it is a bonding coat, not a gap-filling mortar
- Bonds concrete only when the substrate is 3 to 6 weeks old, so very green concrete must wait
- Substrate must be matt damp with no standing water, ice or laitance, or adhesion drops
- Structural bonds must be designed by an engineer; sustained load should stay below 20 to 25 percent of failure load to allow for creep
- Restricted to experienced professionals and not a consumer or general-purpose adhesive
- Hardened residue can only be removed mechanically, so tools must be cleaned before cure with Sika Colma Cleaner
Selection & best practice
Prepare both faces mechanically, by blast cleaning, grinding, scabbling or wire brushing, to an open, sound, contaminant-free profile, then vacuum away all dust. Confirm the concrete is at least three to six weeks old and matt damp rather than wet. Mix full units only: stir Part A, add all of Part B at the 2:1 weight ratio and blend for about four minutes at low speed (max 300 rpm), avoiding over-mixing that whips in air. Apply to both surfaces by brush, roller, trowel or spray, working the product hard into any damp concrete. For fresh-to-hardened concrete, place the new concrete while the film is still tacky; if it turns glossy and loses tack, re-coat before pouring. Only mix what can be used within the pot life, and never open the next unit until the current one is spent. Keep ambient and substrate temperatures between +5 and +40 degrees C and watch the dew point on steel.
Specifications
| Product type | Solvent-free two-component epoxy structural bonding agent (long pot life) |
| Standard compliance | ASTM C881-78, Type II, Grade 2, Class B+C |
| Chemical base | Epoxy resin with selected fillers |
| Mixing ratio | Part A : Part B = 2 : 1 by weight |
| Pot life / open time | >4 hours / >7 hours at +30 degrees C |
| Consumption | Approx. 0.3-0.5 kg/m2 (theoretical, excludes wastage) |
| Max layer thickness | Up to 1 mm |
| Compressive strength | >=35 MPa at 3 days, >=55 MPa at 7 days (ASTM D695, +30 degrees C) |
| Tensile adhesion strength | >=10 MPa at 14 days, moist cure (ASTM C882) |
| Application temperature | Ambient and substrate +5 degrees C min / +40 degrees C max |
| Packaging | 30 kg pre-batched (20 kg A + 10 kg B) and 6 kg pre-batched (4 kg A + 2 kg B) |
Industry use cases
Concrete Repair & Rehabilitation
Acts as the structural bonding coat between old concrete and new repair mortar or overlay, keying the patch into the parent slab so the repair carries load as one section.
Infrastructure & Bridges
Bonds fresh concrete to hardened concrete at construction and segment joints, and fixes steel plates for strengthening, holding up through hot-weather casting programmes.
Industrial Plants & Warehouses
Connects new floor slabs, plinths and machine bases to existing concrete in warm plant interiors where fast epoxies would gel before the joint is closed.
Precast & Prefabrication Yards
Joins precast concrete units, stone and fibre-cement elements structurally, with a long open time that suits staged assembly and larger bonded areas.
Water-Retaining & Marine Structures
Its impermeable, shrinkage-free cured film suits bonding in tanks, channels and coastal works where the joint must resist water and vapour movement.
Frequently asked questions
What does the ‘LP’ in Sikadur-32 LP IN mean?
Can I bond fresh concrete to old concrete with it?
Does the substrate need to be completely dry?
Do I need a separate primer?
How much do I need per square metre?
What pack sizes does it come in, and how long does it keep?
How we position Sika Sikadur-32 LP IN
Sikadur-32 LP IN is the hot-weather grade within Sika’s Sikadur epoxy-bonding line: reach for it when the site is warm and a longer working window matters. Where standard ambient temperatures make pot life less critical, the wider Sikadur bonding-agent range and Sika’s SikaTop and Sika MonoTop repair-mortar systems make natural companions, since this product is the bonding coat those toppings sit on. For grouting steel bases or anchoring after bonding, pair it with Sika’s epoxy or cementitious grouts. Across our other brands, Fosroc’s Nitobond EP and Renderoc repair mortars, MC-Bauchemie and Dr. Fixit repair systems cover similar concrete-repair duties, and our team can match the right bonding agent and mortar to your ambient temperature, substrate condition and structural load.
Fosroc Nitobond EP — A specifier standardised on the Fosroc system, or working in normal ambient temperatures rather than peak summer heat, may prefer Nitobond EP as the equivalent two-component epoxy bonding agent for concrete repair and overlays.
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