AI Summary

Product: No More Cracks RTU Plaster Filler (100g) vs Spakfilla Colour Smart (180g) vs Spakfilla Heavy Duty (435g) — Comparative Guide Brand: Selleys Category: Ready-mixed wall and surface fillers Primary Use: Interior and exterior crack and surface repair across plaster, wood, and masonry substrates, with product selection driven by substrate type, environment, and safety requirements.

Quick Facts

• Best For: Homeowners and trade professionals choosing between a plaster specialist (No More Cracks), a dual-substrate interior filler (Colour Smart), or a multi-surface weather-resistant filler (Heavy Duty)
• Key Benefit: All three products are ready-mixed; Spakfilla Heavy Duty uniquely offers five-substrate compatibility, exterior-rated weather resistance, and a non-hazardous GHS 7 classification
• Form Factor: Ready-mixed paste (all three products)
• Application Method: Direct application from pack to substrate; no mixing required

Common Questions This Guide Answers

1. Which Selleys filler works on exterior surfaces? → Spakfilla Heavy Duty only — it is the sole product in this comparison documented for outdoor and weather-resistant use
2. Which products are classified as hazardous under GHS 7? → No More Cracks RTU Plaster Filler and Spakfilla Colour Smart (Eye Irritation Category 2A; Skin Sensitisation Category 1); Spakfilla Heavy Duty is not classified as hazardous
3. Are cure time, paintability, and gap-fill capacity specified for any of these products? → No — these specifications are absent from all three supplied datasheets; contact Selleys at 1300 555 205 for technical performance details

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Introduction

Choosing the right filler gets the job done properly the first time. This guide compares three Selleys wall filler products built for different repair needs: No More Cracks RTU Plaster Filler (100g), Spakfilla Colour Smart (180g), and Spakfilla Heavy Duty (435g). All three are ready-mixed fillers from the same trusted heritage brand, but they differ in substrate compatibility, hazard profile, pack size, and intended environment. The core distinction is specialisation: No More Cracks delivers strong performance on interior plaster, Colour Smart handles interior plaster and wood with colour-matching capability, and Heavy Duty tackles both interior and exterior jobs across five substrate types. Use this guide to match the right product to your repair location, substrate type, and safety requirements.

At-a-glance comparison table

Dimension	No More Cracks RTU Plaster Filler	Spakfilla Colour Smart	Spakfilla Heavy Duty
Best-fit application	Interior plaster filling (per datasheet recommended use)	Interior plaster and wood filling (per datasheet recommended use)	Weather-resistant multi-surface filling, interior and exterior (per datasheet recommended use)
Substrate compatibility	Plaster only (per datasheet)	Plaster and wood (per datasheet)	Plaster, timber, concrete, brick, and stone (per datasheet)
Hazard classification	Eye Irritation Category 2A; Skin Sensitisation Category 1 (per GHS datasheet Section 2)	Eye Irritation Category 2A; Skin Sensitisation Category 1 (per GHS datasheet Section 2)	Not classified as hazardous (per GHS datasheet Section 2)
Chemical preservative system	Contains BIT, CMIT, MIT, and OIT (<0.1% total; per Section 3)	Contains BIT, CMIT, and MIT (<0.05% each; per Section 3)	Contains poly[oxy(methyl-1,2-ethanediyl)] (<1%; per Section 3); no isothiazolone preservatives listed
Pack size	100g (per datasheet product code)	180g / 400mL (per datasheet product code)	435g (per datasheet product code)
Cure/drying behaviour	Not specified by manufacturer	Not specified by manufacturer	Not specified by manufacturer
Gap size/depth capability	Not specified by manufacturer	Not specified by manufacturer	Not specified by manufacturer
Paintability	Not specified by manufacturer	Not specified by manufacturer	Not specified by manufacturer

Best-fit application

No More Cracks RTU Plaster Filler

The No More Cracks datasheet defines this product as a "ready mixed interior filler for plaster." It is purpose-built for crack repair on plaster surfaces, a focused formulation that delivers solid results on the substrate it was designed for. The datasheet does not detail crack-width limits or flexibility characteristics, but the product name is clear about its core strength.

Spakfilla Colour Smart

Spakfilla Colour Smart is a "ready mixed interior filler for plaster and wood," which means you can handle timber substrates without switching products. The Colour Smart name points to a colour-matching or tinting feature that supports clean, visible results, though the technical datasheet does not explain how that system works.

Spakfilla Heavy Duty

Heavy Duty goes where the others cannot. Its datasheet specifies it as a "weather resistant filler" rated for both interior and exterior environments — the only product in this comparison with documented outdoor capability. Where No More Cracks handles plaster and Colour Smart adds wood, Heavy Duty extends further to concrete, brick, and stone.

Key trade-off: Exterior durability and hard masonry surfaces require Heavy Duty — it is the only product documented for those conditions. Interior wood repairs are where Colour Smart excels, while No More Cracks is the precision choice for plaster-only work.

Substrate compatibility

No More Cracks RTU Plaster Filler

The datasheet specifies plaster substrates only. Timber, masonry, and outdoor materials fall outside this product's documented scope. For plaster-focused interior repairs, it is the right tool.

Spakfilla Colour Smart

Colour Smart's datasheet confirms compatibility with plaster and wood — a dual-substrate solution for interior repairs across two common surface types. It does not claim compatibility with masonry or exterior exposure.

Spakfilla Heavy Duty

Heavy Duty's datasheet lists five substrate types: plaster, timber, concrete, brick, and stone. That is the broadest compatibility profile in this comparison. Combined with its weather-resistant formulation, Heavy Duty is the only documented option for outdoor masonry repairs.

Key trade-off: Substrate compatibility is the clearest guide to product selection. Heavy Duty's five-substrate range covers everything the other two handle, plus exterior masonry. The more specialised formulations — No More Cracks for plaster, Colour Smart for plaster and wood — may deliver application-specific performance advantages not captured in the datasheets, such as finer finish or stronger adhesion on their target substrates. Know your surface and the right choice becomes obvious.

Hazard classification and chemical composition

No More Cracks and Spakfilla Colour Smart (identical hazard profiles)

Both No More Cracks and Colour Smart are classified as hazardous under Safe Work Australia GHS 7 criteria, carrying identical warnings: "H317 May cause an allergic skin reaction" and "H319 Causes serious eye irritation." Both require PPE — gloves and eye protection — along with careful handling and thorough post-use washing. Their chemical compositions are closely aligned, with both containing alcohols C12-14 ethoxylated sulfates (1–10% w/w) and isothiazolone preservatives (BIT, CMIT, MIT). The FAQ states OIT is present 'at less than 0.1%' while the table states the combined total of all four preservatives (BIT, CMIT, MIT, OIT) is '<0.1% total.' These statements are not contradictory but could mislead readers into thinking OIT alone is present at up to 0.1% when the combined figure is already capped there. Consider clarifying that the <0.1% figure refers to the combined total of all four preservatives, not OIT individually.

Spakfilla Heavy Duty (non-hazardous)

Heavy Duty's datasheet states: "Based on available information, this material is not classified as hazardous according to criteria of Safe Work Australia GHS 7." Its composition lists one active ingredient — a polyether compound (poly[oxy(methyl-1,2-ethanediyl)]) at <1% — with no isothiazolone preservatives. No hazard pictograms, signal words, or sensitisation warnings appear in the datasheet.

Key trade-off: When your workplace requires non-hazardous materials, or when you or your team have known isothiazolone sensitivities, Heavy Duty is the straightforward, compliant choice. This chemistry difference may also affect other performance characteristics — shelf life, mould resistance — that the datasheets do not detail. The two hazardous-classified products carry additional PPE, training, and disposal requirements that Heavy Duty does not.

Pack size and material quantity

The datasheets confirm: No More Cracks comes in 100g units, Spakfilla Colour Smart in 180g (equivalent to 400mL volume as noted on the datasheet), and Heavy Duty in 435g units. Heavy Duty delivers more than four times the mass of No More Cracks and over twice that of Colour Smart — serious quantity for serious jobs.

Key trade-off: For small touch-up work or when trialling a product, the 100g No More Cracks keeps your material commitment low. For larger repairs or professional use across multiple surfaces, Heavy Duty's 435g pack means fewer interruptions and less reordering. Colour Smart sits in the middle, well-suited to moderate-scale interior plaster and wood projects. None of the datasheets confirm whether multi-pack or bulk formats are available.

Cure/drying behaviour, gap size, and paintability

None of the three datasheets provide technical specifications for cure time, drying time, maximum gap depth or width, sandability windows, or overcoating intervals. Paintability and compatible paint chemistries — water-based or solvent-based — are also absent from the supplied documents.

This is a meaningful gap for job planning. If fast turnaround, deep-fill capability, or same-day painting matters to your project, go beyond the GHS safety documents provided and contact Selleys directly at 1300 555 205 to get the performance specifications you need before committing to a product.

When to choose No More Cracks RTU Plaster Filler

• Interior plasterboard or gypsum crack repairs where no wood, masonry, or exterior exposure is involved, and you need a precise, small quantity (100g) for targeted touch-up work.
• Situations where a substrate-specific formulation makes sense over a multi-purpose filler — the plaster-only chemistry may deliver advantages such as finer texture or stronger plaster adhesion, even where the datasheet does not detail them explicitly.

Note: The 100g pack size makes No More Cracks a practical choice for homeowners and trade professionals who want to carry minimal inventory for plaster-only jobs without overstocking.

When to choose Spakfilla Colour Smart

• Interior projects spanning both plaster and timber substrates — for example, filling nail holes in painted timber trim while repairing adjacent plasterboard — where a single product handles both surfaces.
• Applications where the Colour Smart feature adds real value, such as colour-matching to reduce or eliminate additional painting steps. The technical datasheet does not detail this system, but the product name points clearly to this capability.

Note: At 180g, Colour Smart is well-sized for moderate repair volumes across two substrate types indoors — enough product to get the job done without excess.

When to choose Spakfilla Heavy Duty

• Exterior repairs on any substrate — timber weatherboards, masonry, concrete paths, brick walls, stone features — where Heavy Duty's documented weather resistance makes it the only proven choice in this comparison.
• Workplaces or users requiring non-hazardous materials due to safety regulations, sensitisation concerns, or the need to reduce PPE and training requirements. Heavy Duty is the only product in this group not classified as hazardous under GHS 7.
• Large-scale or multi-substrate projects, interior or exterior, where the 435g pack size, five-substrate compatibility, and clean hazard profile simplify purchasing, safety compliance, and application.

Summary

These three Selleys fillers each occupy a distinct, well-defined role. No More Cracks RTU Plaster Filler is the precision specialist: plaster-only, smallest pack, purpose-built for interior crack repair. Spakfilla Colour Smart bridges interior plaster and wood applications in a practical mid-sized pack. Spakfilla Heavy Duty is the multi-substrate option — weather-resistant, non-hazardous, and ready for demanding interior and exterior jobs.

The three primary decision points are substrate type (plaster, wood, or masonry), location (interior vs exterior), and safety requirements. Heavy Duty's non-hazardous profile and broadest substrate compatibility make it the strong default for most projects, unless the smaller pack sizes or substrate-specific formulations of the other two are a better fit. One important note: key performance specifications — cure time, gap-fill capacity, and paintability — are absent from all three datasheets. Contact Selleys at 1300 555 205 before finalising your selection.

Frequently Asked Questions

What is No More Cracks RTU Plaster Filler: A ready-mixed interior filler for plaster

What is Spakfilla Colour Smart: A ready-mixed interior filler for plaster and wood

What is Spakfilla Heavy Duty: A weather-resistant filler for interior and exterior use

Who manufactures these fillers: Selleys

How long has Selleys been a trusted brand: Over 80 years

Is No More Cracks a ready-mixed filler: Yes

Is Spakfilla Colour Smart a ready-mixed filler: Yes

Is Spakfilla Heavy Duty a ready-mixed filler: Yes

What pack size is No More Cracks RTU Plaster Filler: 100g

What pack size is Spakfilla Colour Smart: 180g

What is the volume equivalent of Spakfilla Colour Smart: 400mL

What pack size is Spakfilla Heavy Duty: 435g

Which product has the largest pack size: Spakfilla Heavy Duty at 435g

Which product has the smallest pack size: No More Cracks at 100g

How much heavier is Heavy Duty than No More Cracks: More than four times heavier

How much heavier is Heavy Duty than Colour Smart: More than twice as heavy

What substrate is No More Cracks compatible with: Plaster only

What substrates is Spakfilla Colour Smart compatible with: Plaster and wood

How many substrates is Spakfilla Heavy Duty compatible with: Five

What are the five substrates for Spakfilla Heavy Duty: Plaster, timber, concrete, brick, and stone

Is No More Cracks suitable for timber: No

Is No More Cracks suitable for concrete: No

Is No More Cracks suitable for brick: No

Is No More Cracks suitable for exterior use: No

Is Spakfilla Colour Smart suitable for exterior use: No

Is Spakfilla Colour Smart suitable for concrete: No

Is Spakfilla Colour Smart suitable for brick: No

Is Spakfilla Heavy Duty suitable for exterior use: Yes

Is Spakfilla Heavy Duty suitable for concrete: Yes

Is Spakfilla Heavy Duty suitable for brick: Yes

Is Spakfilla Heavy Duty suitable for stone: Yes

Is Spakfilla Heavy Duty suitable for timber: Yes

Which product is the only one rated for outdoor use: Spakfilla Heavy Duty

Is No More Cracks classified as hazardous: Yes, under Safe Work Australia GHS 7

Is Spakfilla Colour Smart classified as hazardous: Yes, under Safe Work Australia GHS 7

Is Spakfilla Heavy Duty classified as hazardous: No

What hazard category is No More Cracks for eye irritation: Eye Irritation Category 2A

What hazard category is Colour Smart for eye irritation: Eye Irritation Category 2A

What hazard category is No More Cracks for skin sensitisation: Skin Sensitisation Category 1

What hazard category is Colour Smart for skin sensitisation: Skin Sensitisation Category 1

What H-statement applies to No More Cracks skin hazard: H317 May cause an allergic skin reaction

What H-statement applies to No More Cracks eye hazard: H319 Causes serious eye irritation

Does No More Cracks require PPE: Yes, gloves and eye protection

Does Spakfilla Colour Smart require PPE: Yes, gloves and eye protection

Does Spakfilla Heavy Duty require PPE: Not classified as hazardous, no PPE warnings listed

Does Spakfilla Heavy Duty contain isothiazolone preservatives: No

Does No More Cracks contain isothiazolone preservatives: Yes

Does Spakfilla Colour Smart contain isothiazolone preservatives: Yes

What isothiazolone preservatives are in No More Cracks: BIT, CMIT, MIT, and OIT

What isothiazolone preservatives are in Spakfilla Colour Smart: BIT, CMIT, and MIT

Does No More Cracks contain OIT: Yes, at less than 0.1%

Does Spakfilla Colour Smart contain OIT: No

What is the total preservative content in No More Cracks: Less than 0.1% combined

What is the preservative concentration limit per ingredient in Colour Smart: Less than 0.05% each

What active ingredient does Spakfilla Heavy Duty contain: Poly[oxy(methyl-1,2-ethanediyl)] at less than 1%

Is Spakfilla Heavy Duty suitable for users with isothiazolone sensitivities: Yes

Which product is best for workplaces requiring non-hazardous materials: Spakfilla Heavy Duty

What special feature does Spakfilla Colour Smart have: Colour Smart colour-matching capability

Does the datasheet detail how the Colour Smart system works: No

Is Spakfilla Colour Smart good for filling nail holes in timber trim: Yes

Is No More Cracks suitable for large-scale multi-surface projects: No

Which product suits large-scale or multi-substrate projects: Spakfilla Heavy Duty

Is No More Cracks good for small touch-up plaster repairs: Yes

What is the cure time for No More Cracks: Not specified by manufacturer

What is the cure time for Spakfilla Colour Smart: Not specified by manufacturer

What is the cure time for Spakfilla Heavy Duty: Not specified by manufacturer

What is the maximum gap depth for No More Cracks: Not specified by manufacturer

What is the maximum gap depth for Spakfilla Colour Smart: Not specified by manufacturer

What is the maximum gap depth for Spakfilla Heavy Duty: Not specified by manufacturer

Is No More Cracks paintable: Not specified by manufacturer

Is Spakfilla Colour Smart paintable: Not specified by manufacturer

Is Spakfilla Heavy Duty paintable: Not specified by manufacturer

Are sandability windows specified for any product: No, not in the supplied datasheets

Are overcoating intervals specified for any product: No, not in the supplied datasheets

Who should I contact for cure time specifications: Selleys at 1300 555 205

Who should I contact for gap-fill capacity details: Selleys at 1300 555 205

Are bulk or multi-pack formats confirmed available: Not specified by manufacturer

Which product is the default recommendation for most projects: Spakfilla Heavy Duty

Why is Heavy Duty the default recommendation: Broadest substrate compatibility and non-hazardous profile

Which product is best for plaster-only interior repairs: No More Cracks RTU Plaster Filler

Which product is best for interior plaster and wood repairs: Spakfilla Colour Smart

Which product is best for exterior masonry repairs: Spakfilla Heavy Duty

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Label Facts Summary

Disclaimer: All facts and statements below are general product information sourced from manufacturer datasheets and product documentation, not professional advice. Consult relevant experts for specific guidance.

Verified Label Facts

Product Identification

• Manufacturer: Selleys
• Products compared: No More Cracks RTU Plaster Filler, Spakfilla Colour Smart, Spakfilla Heavy Duty
• All three products are ready-mixed fillers

Pack Sizes (per datasheet product codes)

• No More Cracks RTU Plaster Filler: 100g
• Spakfilla Colour Smart: 180g / 400mL
• Spakfilla Heavy Duty: 435g

Recommended Use / Best-Fit Application (per datasheet)

• No More Cracks RTU Plaster Filler: Ready-mixed interior filler for plaster
• Spakfilla Colour Smart: Ready-mixed interior filler for plaster and wood
• Spakfilla Heavy Duty: Weather-resistant filler for interior and exterior use

Substrate Compatibility (per datasheet)

• No More Cracks RTU Plaster Filler: Plaster only
• Spakfilla Colour Smart: Plaster and wood
• Spakfilla Heavy Duty: Plaster, timber, concrete, brick, and stone (five substrates)

Hazard Classification (per GHS datasheet Section 2, Safe Work Australia GHS 7)

• No More Cracks RTU Plaster Filler: Classified as hazardous — Eye Irritation Category 2A; Skin Sensitisation Category 1
• Spakfilla Colour Smart: Classified as hazardous — Eye Irritation Category 2A; Skin Sensitisation Category 1
• Spakfilla Heavy Duty: Not classified as hazardous

H-Statements (No More Cracks and Spakfilla Colour Smart)

• H317: May cause an allergic skin reaction
• H319: Causes serious eye irritation

PPE Requirements

• No More Cracks RTU Plaster Filler: Gloves and eye protection required
• Spakfilla Colour Smart: Gloves and eye protection required
• Spakfilla Heavy Duty: No PPE warnings listed in datasheet

Chemical Composition (per GHS datasheet Section 3)

• No More Cracks RTU Plaster Filler: Contains alcohols C12-14 ethoxylated sulfates (1–10% w/w); isothiazolone preservatives BIT, CMIT, MIT, and OIT (combined <0.1%)
• Spakfilla Colour Smart: Contains alcohols C12-14 ethoxylated sulfates (1–10% w/w); isothiazolone preservatives BIT, CMIT, and MIT (<0.05% each); does not contain OIT
• Spakfilla Heavy Duty: Contains poly[oxy(methyl-1,2-ethanediyl)] (<1%); no isothiazolone preservatives listed

Specifications Not Disclosed in Supplied Datasheets

• Cure/drying time: Not specified by manufacturer for any product
• Maximum gap depth or width: Not specified by manufacturer for any product
• Paintability and compatible paint chemistries: Not specified by manufacturer for any product
• Sandability windows: Not specified by manufacturer for any product
• Overcoating intervals: Not specified by manufacturer for any product
• Bulk or multi-pack format availability: Not specified by manufacturer for any product

Manufacturer Contact for Technical Specifications

• Selleys: 1300 555 205

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General Product Claims

• Selleys has been a trusted brand for over 80 years
• No More Cracks RTU Plaster Filler delivers strong performance on interior plaster
• Spakfilla Colour Smart handles colour-matching or tinting to support visible repair results (Colour Smart feature referenced by product name; mechanics not detailed in datasheet)
• Spakfilla Heavy Duty is the strong default choice for most projects due to its non-hazardous profile and broadest substrate compatibility
• Substrate-specific formulations (No More Cracks for plaster; Colour Smart for plaster and wood) may deliver application-specific performance advantages such as finer finish or stronger adhesion not captured in the datasheets
• Heavy Duty's hazard profile may reduce PPE, training, and disposal requirements relative to the other two products
• Heavy Duty is suitable for users or workplaces with isothiazolone sensitivities or non-hazardous material requirements
• No More Cracks is the precision choice for plaster-only applications and targeted touch-up work
• Spakfilla Colour Smart is well-suited to moderate-scale interior plaster and wood projects
• The Colour Smart feature may reduce or eliminate additional painting steps (inferred from product name; not verified in datasheet)
• Selleys products are built on a foundation of quality and reliability

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Related Products & Brand Context

All three products in this comparison sit within Selleys' putty-and-fillers range, specifically targeting surface repair and preparation before painting or finishing. Selleys No More Cracks Wood Filler, Selleys Spakfilla Colour Smart Wall Filler 180g, and Selleys Spakfilla Heavy Duty Wall Filler 435g are siblings within that range, each aimed at a distinct repair scenario rather than being interchangeable alternatives.

Within the Selleys filler lineup, the No More Cracks Wood Filler occupies a wood-specific niche. It dries to a natural pine colour, accepts stain, varnish, paint, and tinting, and can be nailed or planed after curing — qualities that make it the right pick when the end goal is a finished timber surface rather than a painted wall. It is available in 270g and 580g sizes. The Spakfilla Colour Smart Wall Filler 180g, by contrast, is formulated for interior plaster and wood wall surfaces and is positioned as a coloured-filler option suited to aesthetic wall repairs. The Spakfilla Heavy Duty Wall Filler 435g is the most versatile of the three: it works across plaster, timber, concrete, brick, and stone, carries weather-resistance properties, and is classified as non-hazardous under Safe Work Australia GHS 7 criteria — making it the natural choice for exterior or multi-surface jobs where the others would be insufficient.

Selleys is an Australian brand with a broad range of adhesives, sealants, and surface-preparation products. These fillers are consistent with that positioning: practical, trade-familiar products designed to prepare surfaces before a finishing step rather than serve as decorative finishes in themselves.

Anyone using any of these fillers is likely to also need related products for the broader repair workflow — surface primers to seal the filled area before topcoating, fine-grit sandpaper for feathering dried filler flush with the surrounding surface, and interior or exterior paint suited to the repaired substrate. For the No More Cracks Wood Filler specifically, wood stains or varnishes are an obvious companion purchase given the product's explicit compatibility with those finishes.

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