Dr. Fixit Crack-X Paste (201)
Single-pack, fibre-reinforced acrylic putty for plaster cracks up to 5 mm — presses in with a putty knife, stays flexible, and takes paint in about six hours.
What is it?
A ready-to-use, fibre-reinforced flexible crack-filling putty based on weather-durable acrylic emulsion polymer with graded fillers. Single pack, no mixing, meets ASTM C 834-91.
Where is it used?
Internal and external cracks up to 5 mm wide in plastered brick masonry walls — shrinkage cracks, hairline cracks widened into a groove, and crack treatment during repaint cycles.
Why use it?
Elastic polymer plus micro-fibres keeps the fill from re-cracking under minor movement, bonds strongly to cementitious plaster, and is overcoatable with polymer paints after about 6 hours.
How is it applied?
Widen the crack to a 3-5 mm V-groove, clean and moisten, prime with a 1:1 paste-and-water coat, then press the paste in with a putty knife while the primer is still tacky and finish flush.
About Dr. Fixit Crack-X Paste (201)
Dr. Fixit Crack-X Paste (201) is Pidilite’s answer to the most common defect a painting contractor meets on site: plaster cracks that reappear through fresh emulsion within a season. It is a single-pack putty made from weather-durable acrylic emulsion polymer, carefully graded fillers, light-fast pigments and micro-fibres. Straight from the container it presses into a prepared groove, grips cementitious plaster without a separate bonding agent, and dries to a white, paintable fill that flexes instead of fracturing. Compliance with ASTM C 834-91 puts it in the recognised class of latex-based fillers rather than ad-hoc site mixes.
Space Arc Engineering stocks genuine Pidilite material in all four pack sizes — 300 g, 500 g, 1 kg and 5 kg — for supply across Delhi NCR and pan-India dispatch. The small packs suit one-flat touch-ups and snag lists; the 5 kg pack serves society repaint contracts where crews treat crack networks floor by floor. Our team can help you separate cosmetic plaster cracks, which this product handles, from structural or moving cracks, which it deliberately does not.
The technical insight
The paste works on two mechanisms. First, as the water phase evaporates, the acrylic emulsion coalesces into a continuous elastic film that binds the graded fillers — the cured fill shows 60-70% elongation at a Shore A hardness of 70-75, so the small thermal and moisture movements that snap a rigid cement or POP fill are simply absorbed. Second, the dispersed micro-fibres act as distributed reinforcement across the crack plane, spreading strain instead of letting it concentrate at one point — this is why the TDS can claim permanent rather than seasonal crack sealing. The trade-off is inherent to water-based chemistry: at 78-82% solids, drying drives 18-20% shrinkage, which is why the method calls for firm compaction into the groove and why deep fills benefit from a second pass. The 12 MPa tensile strength is ample for a non-structural surface repair; it is not, and never claims to be, a structural re-bonding system.
Where it is used
- Shrinkage and hairline cracks in internal wall plaster, widened to a 3-5 mm V-groove before repainting
- External rendered and plastered brick masonry facades, using the weather-durable acrylic base
- Crack treatment during redecoration cycles in housing societies and commercial premises ahead of fresh emulsion
- Non-structural surface cracks in plastered parapets, boundary walls, staircases and lobby walls
- Pre-handover snag-list crack repairs in residential and commercial projects
- Primer duty over prepared cracks — the same paste diluted 1:1 with water before filling
- Crack filling in occupied buildings where a non-toxic, low-hazard, water-clean-up material is required
Key advantages
- Single-pack and ready to use — no mixing station, no wastage from part-used two-component kits
- Micro-fibre reinforcement gives a crack-bridging fill instead of a brittle plug that pops out
- 60-70% elongation accommodates the minor movement that reopens rigid cement-putty repairs
- Overcoatable with any polymer-based paint after about 6 hours, keeping repaint schedules tight
- Excellent adhesion to cementitious plaster with simple moistening — no separate bonding agent
- Non-toxic and non-hazardous; tools and hands clean up with soap and warm water
- Predictable estimating at 25-30 running metres per kg for a 5 mm x 5 mm groove
- Pack sizes from 300 g to 5 kg suit single-flat touch-ups and full repaint contracts alike
Limitations & considerations
- Restricted to cracks up to 5 mm wide — anything wider needs a mortar-based repair, not more paste
- Not for cracks in structural members, expansion joints or separation gaps; these need engineered assessment or a movement-grade sealant
- Will not hold on POP or painter’s putty — cut back to sound plaster before filling
- Water-resistant but not waterproofing — it does not replace a membrane on leaking terraces or damp facades
- 18-20% shrinkage on drying, so deep grooves need firm compaction and often a second application
- Drying is delayed below 10 degrees C, and the fill needs about 8 hours before POP or paint goes over it
Selection & best practice
Preparation decides the result. Rake out every crack wider than 0.5 mm into a 3-5 mm V-groove with a scraper or cutter — a hairline crack filled without widening leaves the paste sitting on the surface with nothing to grip. Clean out dust, oil and loose particles, then moisten the groove. On internal walls, remove POP or painter’s putty until bare plaster is exposed. Brush on a primer coat of the paste diluted 1:1 with water, and fill while that coat is still tacky, not fully dried. Press the paste home with a spatula or putty knife, working it in to avoid cavities and air bubbles, and strike it flush. Allow 4-6 hours to dry, protect from rain in the meantime, and hold off POP or painting for about 8 hours. Wash tools with soap and warm water immediately, and close the container tightly — the balance keeps for the full 12-month shelf life.
Specifications
| Composition and appearance | Acrylic emulsion polymer with graded fillers and micro-fibres; white paste with fibre |
| Density at 30 degrees C | 1.38-1.46 g/ml |
| Solid content at 30 degrees C | 78-82% |
| Tensile strength | 12 MPa |
| Elongation | 60-70% |
| Hardness | Shore A 70-75 |
| Tack-free time | 10-30 minutes |
| Coverage | 25-30 running metres per kg (5 mm deep x 5 mm wide groove) |
| Standard, packs and shelf life | Meets ASTM C 834-91; 300 g, 500 g, 1 kg and 5 kg packs; 12 months in unopened containers |
Industry use cases
Housing Societies and Redecoration
Painting contractors treat entire crack networks during society repaint cycles; the 6-hour paintability means crack filling and first coat can happen inside the same scaffold shift.
Commercial Fit-Outs and Offices
Snag repairs on plastered walls in occupied floors — low odour, water clean-up and fast recoat suit night work where the space must be presentable next morning.
Builders and Developers
Pre-handover snag lists across towers: small packs issued per flat, no mixing supervision needed, and the fill disappears cleanly under the final emulsion coat.
Institutional and Healthcare Buildings
The non-toxic, non-hazardous, water-based formulation lets maintenance teams repair cracks in schools, hospitals and hostels without solvent fumes or special handling.
Facility Management
Recurring facade and common-area crack maintenance; the 12-month shelf life and resealable packs let FM teams hold stock across a maintenance calendar.
Frequently asked questions
Can Crack-X Paste fill cracks wider than 5 mm?
Do I need a separate primer?
How soon can I paint over the repair?
Will it stop water leakage through the wall?
How much do I need for my site?
Can I use it on gaps at ceiling junctions, window frames or expansion joints?
How we position Dr. Fixit Crack-X Paste (201)
Crack-X Paste sits at the cosmetic end of crack repair, and it is honest about that. Within the Dr. Fixit family, pair it sensibly: movement gaps at frames and junctions call for a sealant such as Dr. Fixit MP Sealant, wet-area joints for Dr. Fixit Bathseal, and any actual leakage needs a Dr. Fixit waterproof coating system over the repaired crack, not the paste alone. When a crack runs into structural concrete — beams, columns, slabs — the correct escalation is epoxy injection, where we supply Fosroc Nitofill LV. Space Arc can inspect and tell you which side of that line your cracks fall on before you order.
Fosroc Nitofill LV — Specify Nitofill LV epoxy injection when the crack is in a structural concrete member and needs re-bonding of the section — Crack-X Paste is limited to cosmetic plaster cracks and is expressly excluded from structural use.
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