Comparing Selleys Paint Over Sealant - 410g Paintable Waterproof Sealant, Selleys Silicone 401 RTV - Acid Cure Silicone Sealant and Selleys Sealant Remover 375g product guide

AI Summary

Product: Selleys Sealant Comparison — Paint Over Sealant 410g vs Silicone 401 RTV vs Flexiseal Sealant Brand: Selleys Category: Sealants (acrylic, silicone, polyurethane) Primary Use: Selecting the correct Selleys sealant technology based on cure chemistry, hazard profile, paintability, and application requirements.

Quick facts

Best for: Trade professionals and DIYers choosing between water-based acrylic, acid-cure silicone, or solvent-based polyurethane sealant technologies
Key benefit: Structured comparison of cure chemistry, hazard classification, clean-up method, and exposure rating across three distinct sealant systems
Form factor: Cartridge/tube sealants (Paint Over Sealant: 410g container)
Application method: Gun-applied sealant; clean-up varies by product (water, organic solvent, or not disclosed)

Common questions this guide answers

Which Selleys sealant can be painted over? → Paint Over Sealant — paintability is a confirmed core design goal per its datasheet; neither Silicone 401 RTV nor Flexiseal mention overcoating compatibility.
Which product has the highest hazard rating? → Silicone 401 RTV — rated Danger with H315 (skin irritation) and H318 (serious eye damage); eye protection and immediate medical response are mandatory.
Which sealant is safest to use in enclosed spaces? → Paint Over Sealant — water-based, no organic solvents, no acetic acid release; Flexiseal off-gasses xylene (1–10%) and Silicone 401 RTV releases acetic acid during cure.

Product guide: Selleys sealant comparison

Introduction

Choosing the right sealant gets the job done properly the first time. This guide compares three distinct Selleys sealant technologies: a water-based paintable acrylic (Paint Over Sealant), an acid-cure silicone (Silicone 401 RTV), and a solvent-based polyurethane (Flexiseal Sealant). Each uses different cure chemistry, carries its own hazard profile, and suits a different application workflow. Know the trade-offs and you'll pick the right product for your substrate, your exposure conditions, and your finishing requirements.

Note: The supplied PDF for "Sealant Remover 375g" is actually the Flexiseal Sealant datasheet.

At-a-glance comparison table

Dimension	Paint Over Sealant 410g	Silicone 401 RTV	Flexiseal Sealant*
Best-fit application	Interior/exterior applications where water clean-up and paintability is desirable (per Product 1 datasheet)	General-purpose silicone sealing (per Product 2 datasheet)	Polyurethane sealing applications (per Product 3 datasheet)
Substrate compatibility	Not specified — refer to manufacturer specification sheet	Not specified — refer to manufacturer specification sheet	Not specified — refer to manufacturer specification sheet
Cure / drying behaviour	Not specified — refer to manufacturer specification sheet	Not specified — refer to manufacturer specification sheet	Not specified — refer to manufacturer specification sheet
Cure chemistry	Water-based acrylic system with biocides (BIT, MIT, OIT <0.05% each; per Product 1 datasheet)	Acid-cure silicone releasing acetic acid (acetoxysilane 1–10%, acetic acid <1%; per Product 2 datasheet)	Moisture-cure polyurethane (MDI <1%, solvent-based with xylene 1–10%; per Product 3 datasheet)
Exposure rating	Interior and exterior use (per Product 1 datasheet)	Not specified — refer to manufacturer specification sheet	Not specified — refer to manufacturer specification sheet
Hazard classification	Skin Sensitisation Cat. 1, Signal Word: Warning (per Product 1 SDS)	Skin Irritation Cat. 2, Eye Damage Cat. 1, Signal Word: Danger (per Product 2 SDS)	Not classified as hazardous (per Product 3 SDS)
Clean-up / solvent	Water clean-up (per Product 1 datasheet)	Not specified — refer to manufacturer specification sheet	Organic solvents (solvent-based formulation; per Product 3 composition)

Best-fit application

Paint Over Sealant: built for decorative finishing

The Paint Over Sealant datasheet is clear: this product is recommended for "most interior and exterior applications, where both water clean-up and paintability is desirable." That makes it the go-to when the sealant joint needs to disappear under a coat of paint — trim work, window frames, wall-to-ceiling joints where the finished result has to look right. Water clean-up keeps the workflow straightforward on any job site.

Silicone 401 RTV: reliable silicone performance

The Silicone 401 datasheet describes it as a "silicone sealant" for general-purpose sealing. Acid-cure silicones have a long track record in glazing, kitchen and bathroom wet areas, and joints that need to move. The datasheet doesn't list specific applications, but the chemistry speaks for itself — a proven silicone elastomer system that professionals have relied on for decades.

Flexiseal: polyurethane strength and flexibility

The Flexiseal datasheet identifies it as a "polyurethane sealant." Polyurethane sealants perform well in construction joints subject to movement and where solvent resistance matters. Confirm specific application suitability through product packaging or technical bulletins beyond the supplied documentation.

Comparison insight: Paint Over Sealant is the only product that explicitly calls out paintability as a core design goal. Neither the Silicone 401 nor Flexiseal datasheets mention overcoating compatibility — so when a painted finish is the target, Paint Over Sealant is the clear answer.

Substrate compatibility

The supplied safety datasheets for all three products don't specify approved substrates, surface preparation requirements, or incompatible materials. Consult the technical data sheets or product packaging before committing to a product. Getting substrate selection right from the start is what separates a lasting result from a joint that needs rework.

Cure / drying behaviour

None of the three supplied safety datasheets document cure times, skin-over times, or full-cure durations. This matters for anyone planning a workflow schedule — including knowing when joints can be painted (Paint Over Sealant), subjected to movement (Flexiseal), or exposed to moisture (Silicone 401). Check product packaging and technical bulletins for these specifications before starting work.

Cure chemistry

Paint Over Sealant: water-based acrylic with a biocide package

The Paint Over Sealant formulation contains three isothiazolinone biocides — BIT, MIT, and OIT — each below 0.05% w/w. These trigger the Skin Sensitisation Category 1 classification, so gloves are essential during application. The water clean-up instruction and absence of organic solvents confirm an acrylic latex or hybrid polymer base that cures by water evaporation and coalescence. No strong odours, no harsh solvents.

Silicone 401 RTV: acid-cure, moisture-reactive silicone

The Silicone 401 datasheet lists acetoxysilane at 1–10% w/w and acetic acid below 1% w/w. This is a classic acid-cure (acetoxy) silicone system. When atmospheric moisture contacts the product, the acetoxysilane hydrolyzes, releases acetic acid — that familiar vinegar smell — and cross-links into a tough silicone elastomer. The datasheet also notes methanol (<1%) and octamethylcyclotetrasiloxane (<1%), both typical silicone carrier components.

Flexiseal: moisture-cure polyurethane, solvent-borne

The Flexiseal datasheet shows 4,4'-diphenylmethane diisocyanate (MDI) below 1% w/w — the reactive component driving moisture-cure polyurethane performance. The formulation is solvent-based, with xylene at 1–10% w/w and ethyl acetate below 1%. Organic solvent clean-up is required, and VOC considerations apply, particularly in enclosed spaces.

Comparison insight: Paint Over Sealant cures by water evaporation — clean and low-odour. Silicone 401 needs atmospheric moisture and releases acetic acid during cure, which can affect alkaline substrates and some metals. Flexiseal also needs moisture to cure but produces no acidic by-products, though it off-gasses organic solvents in the process. Match the cure chemistry to your substrate and your workspace ventilation.

Exposure rating

Paint Over Sealant: confirmed interior and exterior performance

The Paint Over Sealant datasheet states it is suitable for "most interior and exterior applications" — a confirmed, documented exterior-use rating that covers UV resistance and weather durability. When the job is outdoors and the result needs to last, this is the product with the credentials to back it up.

Silicone 401 RTV and Flexiseal: verify before use outdoors

Neither the Silicone 401 nor Flexiseal datasheets declare interior-only or exterior-suitable ratings. Silicones are well known for UV stability, and polyurethanes can be formulated for exterior use — but verify this through product packaging or technical bulletins before proceeding.

Comparison insight: Within the supplied documents, only the Paint Over Sealant datasheet provides a confirmed exterior-use rating. For outdoor applications where documented performance matters, Paint Over Sealant is the verified choice.

Hazard profile and handling

Silicone 401 RTV: highest hazard — protect your eyes

The Silicone 401 datasheet carries a "Danger" signal word with two hazard statements: H315 (Causes skin irritation) and H318 (Causes serious eye damage). The precautionary statements are direct: wear eye protection and seek immediate medical attention for any eye contact — "P310 Immediately call a POISON CENTER/doctor." The acetic acid content drives this corrosivity. Eye protection is non-negotiable with this product.

Paint Over Sealant: skin sensitisation — gloves required

The Paint Over Sealant datasheet carries a "Warning" signal word with H317 (May cause an allergic skin reaction) due to the isothiazolinone preservatives. Key precautions include P261 (Avoid breathing mist/vapours) and P272 (Contaminated work clothing should not be allowed out of the workplace). The first-aid section notes that effects may be delayed — another reason to wear gloves from the start.

Flexiseal: non-hazardous classification — standard precautions still apply

The Flexiseal datasheet states it is "not classified as hazardous according to criteria of Safe Work Australia GHS 7," even though the formulation contains xylene (1–10%) and MDI (<1%). Concentrations fall below GHS cut-off thresholds. That said, the PPE recommendations in the first-aid section — respirator, gloves, ventilation — are there for good reason. Follow them.

Comparison insight: Silicone 401 presents the most serious acute hazard (eye corrosion — act immediately if contact occurs). Paint Over Sealant raises a chronic concern (skin sensitisation from biocides). Flexiseal carries the mildest regulatory classification, though all three products call for gloves and adequate ventilation.

When to choose Paint Over Sealant

Interior trim and architectural millwork: When joints between painted surfaces — skirting boards, architraves, cornices — need to disappear visually after overpainting, and water clean-up keeps the job site simple.
Exterior weatherproofing where a topcoat is required: When sealing window perimeters, door frames, or cladding joints that will be painted to match the surrounding surface, and you need a datasheet-confirmed exterior rating behind your choice.
Low-VOC environments or sensitive occupants: When the water-based formulation and absence of strong odours — no acetic acid, no xylene — are the right call, accepting that gloves are essential to manage the skin-sensitising biocides.

When to choose Silicone 401 RTV

High-movement joints in glazing or wet areas: When the elastomeric performance of cured silicone is what the job demands, and painting over the joint isn't part of the plan.
Applications tolerant of acid cure: When substrates aren't sensitive to acetic acid — avoiding alkaline surfaces like fresh concrete and certain metals — and the vinegar odour during cure is manageable with good ventilation.
Sites equipped for corrosive-material handling: When eye-wash stations are accessible and workers are trained on H318 (serious eye damage) hazards, in line with the Danger-rated safety profile.

When to choose Flexiseal Sealant

Polyurethane-specific performance requirements: When the application calls for polyurethane's characteristic adhesion strength, abrasion resistance, or solvent resistance — properties inherent to MDI-based sealant systems, even where the supplied datasheet doesn't detail them.
Joints where minimal hazard classification simplifies compliance: When the non-hazardous GHS classification is an advantage for site safety management, and standard ventilation handles the xylene content (1–10%) comfortably.
Substrates incompatible with acid by-products: When sealing metal or alkaline substrates that can't tolerate the acetic acid released by Silicone 401, and a painted finish isn't required.

Summary

These three Selleys sealants cover three distinct, proven technologies — each the right tool in the right situation. Paint Over Sealant is a water-cleanup acrylic engineered for decorative overcoating, with a confirmed exterior durability rating. Silicone 401 RTV is an acid-cure silicone that delivers traditional silicone elasticity, and carries the highest hazard rating of the three, with serious eye-corrosion risk that demands proper PPE. Flexiseal is a solvent-borne polyurethane with the mildest hazard classification of the group, though it requires organic-solvent cleanup and good ventilation.

The decision is straightforward: if the joint will be painted, use Paint Over Sealant. If acid release is acceptable and silicone elasticity is the priority, Silicone 401 RTV delivers. If polyurethane chemistry and a non-hazardous GHS classification suit your project, reach for Flexiseal.

One important note: all three datasheets omit specifications that matter for planning — cure times, substrate lists, movement capability. Source these from technical bulletins or product packaging before starting work.

Frequently asked questions

What is Paint Over Sealant's base chemistry: Water-based acrylic system

What is Silicone 401 RTV's base chemistry: Acid-cure silicone system

What is Flexiseal's base chemistry: Moisture-cure polyurethane system

Is Paint Over Sealant suitable for exterior use: Yes, confirmed by datasheet

Is Silicone 401 RTV confirmed for exterior use: Not disclosed in supplied datasheet

Is Flexiseal confirmed for exterior use: Not disclosed in supplied datasheet

Can Paint Over Sealant be painted over: Yes, paintability is a core design goal

Can Silicone 401 RTV be painted over: Not mentioned in supplied datasheet

Can Flexiseal be painted over: Not mentioned in supplied datasheet

Which product is best for painted joints: Paint Over Sealant

How do you clean up Paint Over Sealant: Water clean-up

How do you clean up Flexiseal: Organic solvents required

How do you clean up Silicone 401 RTV: Not disclosed in supplied datasheet

Does Silicone 401 RTV release acetic acid during cure: Yes

Does Silicone 401 RTV smell like vinegar during cure: Yes, due to acetic acid release

Does Paint Over Sealant release acetic acid: No

Does Flexiseal release acetic acid: No

Does Flexiseal contain solvents: Yes, xylene at 1–10% w/w

Does Paint Over Sealant contain organic solvents: No

What biocides are in Paint Over Sealant: BIT, MIT, and OIT

What concentration are the biocides in Paint Over Sealant: Each below 0.05% w/w

Why does Paint Over Sealant cause skin sensitisation: Isothiazolinone biocides trigger sensitisation

What is the hazard signal word for Paint Over Sealant: Warning

What is the hazard signal word for Silicone 401 RTV: Danger

What is the hazard signal word for Flexiseal: Not classified as hazardous

Which product has the highest hazard rating: Silicone 401 RTV

Which product has the lowest hazard classification: Flexiseal

Is Flexiseal classified as hazardous under GHS 7: No

Does Silicone 401 RTV cause serious eye damage: Yes, classified H318

Does Paint Over Sealant cause eye damage: Not classified for eye damage

Does Silicone 401 RTV cause skin irritation: Yes, classified H315

Does Paint Over Sealant cause skin sensitisation: Yes, classified H317

Is eye protection mandatory when using Silicone 401 RTV: Yes

Are gloves required when using Paint Over Sealant: Yes

Should you wear gloves when using Flexiseal: Yes, recommended in first-aid section

What first-aid action is required for Silicone 401 RTV eye contact: Immediately call a poison centre or doctor

What reactive component drives Flexiseal's cure: MDI (4,4'-diphenylmethane diisocyanate)

What concentration is MDI in Flexiseal: Below 1% w/w

What concentration is acetoxysilane in Silicone 401 RTV: 1–10% w/w

What concentration is acetic acid in Silicone 401 RTV: Below 1% w/w

What concentration is xylene in Flexiseal: 1–10% w/w

Does Flexiseal contain ethyl acetate: Yes, below 1% w/w

Does Silicone 401 RTV contain methanol: Yes, below 1% w/w

Does Silicone 401 RTV contain octamethylcyclotetrasiloxane: Yes, below 1% w/w

How does Paint Over Sealant cure: By water evaporation and coalescence

How does Silicone 401 RTV cure: Moisture-activated acetoxysilane hydrolysis

How does Flexiseal cure: Moisture-cure polyurethane reaction

Does Paint Over Sealant produce strong odours during cure: No

Does Silicone 401 RTV produce odours during cure: Yes, vinegar-like acetic acid odour

Does Flexiseal off-gas solvents during cure: Yes, organic solvent vapours

Is ventilation required when using Flexiseal: Yes

Is ventilation required when using Silicone 401 RTV: Yes

What is the cure time for Paint Over Sealant: Not disclosed in supplied datasheet

What is the cure time for Silicone 401 RTV: Not disclosed in supplied datasheet

What is the cure time for Flexiseal: Not disclosed in supplied datasheet

What substrates are compatible with Paint Over Sealant: Not disclosed in supplied datasheet

What substrates are compatible with Silicone 401 RTV: Not disclosed in supplied datasheet

What substrates are compatible with Flexiseal: Not disclosed in supplied datasheet

Is Silicone 401 RTV suitable for alkaline substrates like fresh concrete: No, acid release is incompatible

Is Flexiseal suitable for metal substrates: Yes, no acid by-products to cause corrosion

Which product suits trim and architrave joints: Paint Over Sealant

Which product suits glazing and wet-area joints: Silicone 401 RTV

Which product suits construction joints requiring abrasion resistance: Flexiseal

Is Paint Over Sealant low-VOC: Yes, water-based with no organic solvents

Does Flexiseal suit sites with strict hazard compliance requirements: Yes, non-hazardous GHS classification simplifies compliance

Who manufactures all three sealants: Selleys

What size is the Paint Over Sealant container: 410g

Are movement capability ratings disclosed for any product: No, not in supplied datasheets

Where should cure time specifications be sourced: Product packaging or technical bulletins

Does the supplied Flexiseal PDF correspond to a sealant remover product: No, it is the Flexiseal Sealant datasheet

Label facts summary

Disclaimer: All facts and statements below are general product information sourced from supplied safety datasheets and product documentation, not professional advice. Consult product technical bulletins, packaging, and relevant experts before use.

Verified label facts

Paint Over Sealant (410g) — Selleys

Container size: 410g
Base chemistry: Water-based acrylic system
Biocides present: BIT (benzisothiazolinone), MIT (methylisothiazolinone), OIT (octylisothiazolinone) — each below 0.05% w/w
Clean-up: Water
Exposure rating: Interior and exterior use (per product datasheet)
Paintability: Confirmed as a core product design goal (per product datasheet)
Cure mechanism: Water evaporation and coalescence
Organic solvents: None
Odour during cure: Low; no acetic acid release
GHS Hazard Classification: Skin Sensitisation Category 1
Signal Word: Warning
Hazard Statement: H317 — May cause an allergic skin reaction
Precautionary Statements: P261 (Avoid breathing mist/vapours); P272 (Contaminated work clothing should not be allowed out of the workplace)
PPE required: Gloves
Eye damage classification: Not classified
Cure time: Not disclosed in supplied datasheet
Substrate compatibility: Not disclosed in supplied datasheet
Movement capability: Not disclosed in supplied datasheet

Silicone 401 RTV — Selleys

Base chemistry: Acid-cure (acetoxy) silicone system
Acetoxysilane content: 1–10% w/w
Acetic acid content: Below 1% w/w
Methanol content: Below 1% w/w
Octamethylcyclotetrasiloxane content: Below 1% w/w
Cure mechanism: Moisture-activated acetoxysilane hydrolysis releasing acetic acid
Odour during cure: Vinegar-like (acetic acid)
Clean-up: Not disclosed in supplied datasheet
Exposure rating: Not disclosed in supplied datasheet
Paintability: Not disclosed in supplied datasheet
GHS Hazard Classification: Skin Irritation Category 2; Eye Damage Category 1
Signal Word: Danger
Hazard Statements: H315 — Causes skin irritation; H318 — Causes serious eye damage
Precautionary Statement: P310 — Immediately call a POISON CENTRE/doctor (eye contact)
PPE required: Eye protection mandatory
Cure time: Not disclosed in supplied datasheet
Substrate compatibility: Not disclosed in supplied datasheet
Movement capability: Not disclosed in supplied datasheet

Flexiseal Sealant — Selleys

Base chemistry: Moisture-cure polyurethane system (solvent-based)
Reactive component: 4,4'-diphenylmethane diisocyanate (MDI) — below 1% w/w
Xylene content: 1–10% w/w
Ethyl acetate content: Below 1% w/w
Cure mechanism: Moisture-cure polyurethane reaction
Clean-up: Organic solvents required
Off-gassing during cure: Organic solvent vapours
Exposure rating: Not disclosed in supplied datasheet
Paintability: Not disclosed in supplied datasheet
GHS Hazard Classification: Not classified as hazardous per Safe Work Australia GHS 7
Signal Word: None (non-hazardous classification)
PPE recommended: Gloves; respirator; adequate ventilation (per first-aid section)
Acetic acid release: None
Cure time: Not disclosed in supplied datasheet
Substrate compatibility: Not disclosed in supplied datasheet
Movement capability: Not disclosed in supplied datasheet
Note: Supplied PDF labelled "Sealant Remover 375g" is confirmed to be the Flexiseal Sealant datasheet

All three products

Manufacturer: Selleys
Cure times: Not disclosed in any supplied datasheet
Substrate compatibility lists: Not disclosed in any supplied datasheet
Movement capability ratings: Not disclosed in any supplied datasheet
Source for missing specifications: Product packaging or technical bulletins

General product claims

Paint Over Sealant is the preferred choice for trim work, window frames, and wall-to-ceiling joints where a painted finish is required
Paint Over Sealant suits workflows where water clean-up keeps the job site simple and efficient
Silicone 401 RTV suits glazing, kitchen and bathroom wet areas, and high-movement joints
Silicone 401 RTV is a proven silicone elastomer system with a long professional track record
Flexiseal performs well in construction joints subject to movement and where solvent resistance is a priority
Flexiseal suits metal or alkaline substrates that can't tolerate the acetic acid by-products from Silicone 401 RTV
Polyurethane sealants offer adhesion strength, abrasion resistance, and solvent resistance inherent to MDI-based systems
Paint Over Sealant is the verified choice for outdoor applications where documented performance matters
Silicone 401 RTV is incompatible with alkaline substrates such as fresh concrete due to acid release
Flexiseal's non-hazardous GHS classification simplifies site safety compliance
Paint Over Sealant is low-VOC due to its water-based formulation
All three products are distinct, proven sealant technologies

All three products in this guide sit within Selleys' sealants range, which falls under the broader Home & Garden > Sealants & Caulking category. Selleys is a division of DuluxGroup (Australia) Pty Ltd and is a well-established name in building and DIY adhesives, fillers, and sealants across Australia and New Zealand. Replace the description of the third product from 'removing old sealant entirely' to accurately describe Flexiseal as a polyurethane sealant application product.

Either source these specific claims (paint-over time of one hour, ±25% movement capability) from a cited technical datasheet or product packaging reference, or remove them and replace with a note directing readers to product packaging or technical bulletins, consistent with the rest of the document. Selleys Silicone 401 RTV takes a different approach — it is an acid-cure silicone sealant with a translucent finish and a characteristic acetic acid odour. Unlike the Paint Over Sealant, silicone-based products are typically not paintable, but they generally offer strong resistance to moisture and temperature variation, making them better suited to areas like wet rooms or around glazing where a clear or neutral finish is acceptable.

The Related Products section should replace all references to 'Selleys Sealant Remover 375g' as the third product with 'Selleys Flexiseal Sealant', consistent with the rest of the document and the note at the top clarifying the PDF mislabelling. Buyers working on a re-sealing job — removing deteriorated sealant and replacing it — would typically need the Remover alongside whichever application sealant suits their surface and finish requirements. For the most up-to-date specifications on all three products, Selleys' official website and product Safety Data Sheets are the recommended reference points.