What is Selleys Paint Over Sealant, and where should you use it?

Selleys Paint Over Sealant is a water-based acrylic polymer sealant made to be painted. Its point of difference is the wait time: it is paintable in one hour, which is what turns a gap-filling job and a painting job into the same afternoon rather than two separate visits.

It suits the joints that end up under a paint finish — gaps around windows and doors, and cracks in walls and ceilings — on glass, aluminium, fibre cement, masonry, metals, plastics, timber and plasterboard. It is water and UV resistant and is suitable for damp and humid areas.

What "paintable in 1 hour" actually means for your job

Selleys marks the one-hour claim with an asterisk, and the accompanying instruction is straightforward: you must allow one hour before painting. Treat it as a minimum, not a target. The sealant is designed to accept gloss, semi gloss and low sheen paints, and it takes both water-based and oil-based paints — which is a wider range than most sealants accommodate, and the reason it works as a general-purpose pre-paint filler rather than only under a flat wall finish.

Being a water-based acrylic is what makes that possible. It also sets the rest of the working method: excess wipes off with a damp cloth rather than a solvent, and the finish depends entirely on tooling before the surface skins.

Work in sections — the finish depends on it

The single piece of technique advice Selleys attaches to this product is worth reading twice: work in sections that can be completed before the sealant skins. Tooling off and tape removal must both be finished before skinning occurs, or a rough surface may result.

In practice that means resisting the urge to run the bead down a whole wall and come back to tool it. Do a length you can confidently finish — bead, tool, pull the tape — then move on. A rough, skinned bead cannot be smoothed back; the only remedy is to cut it out and start again, and on a surface about to be painted a poor tool-off shows through the finish coat.

Where to use it

Paint Over Sealant is suitable for use on:

• Glass
• Aluminium
• Fibre cement
• Masonry
• Metals
• Plastics
• Timber
• Plasterboard

It is suitable for damp and humid areas, and it is water and UV resistant, so it is not restricted to dry interior work. The typical applications are filling gaps around windows and doors and sealing cracks in walls and ceilings before painting.

How to apply it

1. Make sure the surface is clean and dry.
2. Cut the cartridge and apply the sealant with a caulking gun.
3. Tool the bead with a spatula, working in sections short enough to finish before the sealant skins.
4. Wipe away excess with a damp cloth while the product is still workable.
5. Remove any masking tape before skinning occurs — tape pulled after the surface has skinned drags the edge of the bead.
6. Allow one hour before painting.

Limitations to observe

• You must allow one hour before painting. Painting sooner is working against the product's stated requirement.
• Tooling and tape removal must be completed before the sealant skins, or the finished surface will be rough.

Beyond those, Selleys does not publish a technical data sheet for Paint Over Sealant, so there are no published figures here for cure rate, joint movement capability, service temperature, hardness or elongation. If your job depends on a specific movement capability or temperature rating — an external expansion joint, for example, or a joint next to a heat source — choose a product whose data sheet states the number rather than assuming this one will cover it.

Clean up

Wipe excess product away with a damp cloth. As a water-based acrylic, it does not need a solvent for clean-up while it is still wet, which is one of the practical advantages over a silicone in a room you are about to paint.

Hazard classification

Classified as hazardous under Safe Work Australia GHS 7, with the signal word Warning.

• Skin sensitisation — Category 1. H317: may cause an allergic skin reaction.

It is not classified as Dangerous Goods for road, rail, sea or air transport — not under the Australian Code for the Transport of Dangerous Goods by Road & Rail or New Zealand NZS5433, and not under the IMDG Code or the IATA Dangerous Goods Regulations.

What is in it

Chemical entity	CAS number	Proportion (w/w)
1,2-Benzisothiazol-3(2H)-one (BIT)	2634-33-5	<0.05%
2-Methyl-2H-isothiazol-3-one (MIT)	2682-20-4	<0.05%
2-Octyl-2H-isothiazol-3-one (OIT)	26530-20-1	<0.05%
Ingredients determined to be non-hazardous or below reporting limits	—	Balance

Three declared components, each under half of one tenth of one per cent, and a single hazard class between them. All three are isothiazolinones — the preservative class routinely used to stop water-based products spoiling in the tin, and the class most often behind an H317 on a water-borne formulation. Read alongside the fact that the sealant is a water-based acrylic, that is a coherent picture: the polymer is not what carries the classification, the preservative system is. Treat the causal link as inference from the chemistry rather than something the data sheet states.

Sensitisation is not irritation, and the difference is the reason this section is here. An irritant burns or reddens while it is in contact and settles once it is washed off. A sensitiser teaches the immune system to react to it. Once that has happened it is generally permanent, it is set off thereafter by exposures far smaller than the one that caused it, and each subsequent contact tends to be worse rather than milder. It is also not a one-off-accident hazard: sensitisation develops from repeated, unremarkable contact. The data sheet's own phrasing for skin contact is that effects may be delayed — a rash that appears the following morning rather than at the moment of contact is the classic signature.

Now read that against how this product is actually used. The method on the page above is to work in short sections, tool each bead before it skins, pull the tape, and move on — then repeat down the whole wall. Being water-based is precisely what makes a damp cloth and a wet fingertip the natural tools, where a silicone would have sent you for turps and a spatula. A painter running gap seal around every window and cornice in a house is getting exactly the pattern of exposure — low dose, bare skin, many repetitions — that produces sensitisation. Wear gloves and tool with a tool.

Note what is not on the list, because it is genuine good news and it shapes the rest of the handling. There is no flammability classification, no eye damage or eye irritation classification, no respiratory hazard and no dangerous goods classification by any transport mode. Natural ventilation is stated as adequate in normal use. This is a low-hazard product with one specific catch, and the catch is your hands.

Protection

• Gloves — the important one for this product. Nitrile rubber is indicated as suitable for intermittent contact; glove construction and site conditions vary, so make the final assessment yourself.
• Eye protection — safety glasses.
• Clothing — overalls and safety shoes.
• Ventilation — natural ventilation is adequate in normal use; no special extraction is called for.
• Wash hands before smoking, eating, drinking or using the toilet, and wash contaminated clothing before storing or re-using it.
• Store in a cool, dry, well-ventilated place out of direct sunlight, away from foodstuffs and incompatible materials.

First aid

Exposure	What to do
Skin	Effects may be delayed, so act promptly. Remove contaminated clothing and flush the skin and hair thoroughly with running water. If swelling, redness, blistering or irritation develops — including hours later — seek medical assistance. A reaction appearing after the event may be an allergic response rather than simple irritation, and it is worth having recorded.
Eyes	Wash out immediately with water. As a sensible precaution, seek medical advice in all cases of eye contamination.
Inhalation	Move the person to fresh air without becoming a casualty yourself. Remove contaminated clothing and loosen the rest, let them settle into the most comfortable position and keep them warm and at rest until fully recovered. Seek medical advice if effects persist.
Swallowed	Rinse the mouth with water. Do not induce vomiting. Give a glass of water to drink. Never give anything by mouth to an unconscious person. If vomiting occurs, give further water and seek medical advice.

If poisoning occurs, contact a doctor or the Poisons Information Centre — 131 126 in Australia, 0800 764 766 in New Zealand — with the container to hand. Selleys emergency line: 1800 220 770 in Australia, 0800 220 770 in New Zealand.

Common questions about Selleys Paint Over Sealant

How long do I have to wait before painting?

One hour. This is stated as a requirement, not a suggestion.

What kinds of paint can I use over it?

Gloss, semi gloss and low sheen paints, in both water-based and oil-based formulations.

What is it made of?

It is a water-based acrylic polymer sealant.

Can I use it in a bathroom or laundry?

It is stated to be suitable for damp and humid areas. For a shower recess or a joint under constant water contact, look at the purpose-built wet area silicone range instead — those products publish wet-area performance data that this one does not.

Will it stick to plasterboard?

Yes. Plasterboard is one of the listed surfaces, along with timber, fibre cement, masonry, metals, plastics, glass and aluminium.

Is it suitable for outdoor use?

It is described as water and UV resistant. No service temperature range or joint movement figure is published for it, so for an exposed external joint that has to move, check a product with a published movement capability.

How do I get a neat finish?

Work in short sections and tool each one before it skins. Remove masking tape before skinning as well — both steps have to happen inside that window.

What happens if I miss the tooling window?

The manufacturer's warning is that a rough surface may result. There is no way to smooth a skinned bead; cut it out and redo that section.

How do I clean up excess sealant?

Wipe it with a damp cloth.

What surface preparation does it need?

The surface must be clean and dry before you apply the sealant.

Is there a technical data sheet for it?

No technical data sheet is published for Paint Over Sealant, so figures such as cure rate, hardness and elongation are not available for this product.

What if I need a sealant that is not going to be painted?

Browse the multi-purpose sealant range, or read the background on types of sealants to work out which chemistry suits the joint.