What is Selleys Pro Trade All Purpose Silicone, and where should you use it?

Selleys Pro-Trade All Purpose is a high quality 100% neutral cure silicone containing fungicide to prevent mould and mildew growth in hot and humid areas. It reacts with atmospheric moisture to produce a form-in-place silicone rubber seal, and it works as both an adhesive and a sealant across shower screens, baths, vanities, basins, kitchens and waterproofing.

The one thing to decide before you buy it: it cannot be successfully painted over. If the joint is going to sit under a paint finish, this is the wrong product and no amount of careful preparation will change that. Complete your painting before applying the sealant. Within that constraint it is a broadly compatible neutral cure silicone that will not corrode metals and carries ±25% joint movement capability.

Technical specification

Property	Typical result
Technology	Neutral cure silicone
Colour	Clear
Density	1.04
Application temperature	Minimum 5°C
Skin time (25°C / 50% RH)	4 to 8 minutes
Cure rate	10mm in 5 to 7 days
Slump (JIS A 1439)	No slump (0.1% max)
Tensile strength (JIS K 6249)	2.0 MPa
Shore A hardness (ASTM D2240)	28
Elongation at break (JIS K 6249)	400%
Movement capability	±25%
Service temperature	-60°C to 170°C
VOC content (SCAQMD Method 304-91)	30 g/L
Standards	BS 5889 approved
Packaging	300g cartridge, clear

These are indicative data only, not intended for the preparation of specifications.

What the key numbers mean in practice

The skin time of 4 to 8 minutes is short, and the tooling time given in the directions is 5 to 8 minutes. That is your entire window to shape the bead. Plan the job in lengths you can bead and tool inside eight minutes; a long run laid down before you start tooling will have skinned at the far end before you reach it, and tooling a skinned bead tears the surface instead of smoothing it.

The tack free time is approximately one hour — the point at which the surface stops picking up dust and fingerprints. That is a different milestone again from the cure rate of 10mm in 5 to 7 days, which describes how deep the cure travels. A shallow bead in a shower screen joint is through-cured well inside a week; a deep joint takes longer, and because the product cures by reacting with atmospheric moisture, a joint enclosed on all sides cures more slowly still.

±25% movement capability with 400% elongation at break and a Shore A hardness of 28 describes a soft, elastic seal that stretches with the joint. The no-slump rating (0.1% maximum) is the other practical figure: it means a vertical bead holds its profile instead of sagging down the joint before it skins.

The service temperature range of -60°C to 170°C is wide, and a VOC content of 30 g/L meets the GBCA limit of maximum 50 g/L — relevant on green-rated commercial jobs where the specification puts a cap on VOC content.

Where to use it

Pro-Trade All Purpose is suitable as an adhesive and sealant for applications including:

• Shower screens
• Baths
• Vanities and basins
• Kitchens
• Waterproofing

It is described as ideal for most common building substrates, including glass, most metals (aluminium, steel and the like), concrete, brick, plasterboard, wood, ceramics, most plastics and most powder coated surfaces. Pre-testing on substrates is recommended in all cases, and the product page adds that it is not suitable for some plastics without testing — PE, PP and PTFE among them.

Being neutral cure, it will not corrode metals. That is the main reason to choose it over an acetic cure silicone where the joint involves metal fittings or powder coated frames.

Surface preparation

Surfaces must be clean, dry, and free of dirt, grease, oil and water. Metal and glass surfaces should be cleaned with general-purpose thinners or mineral turpentine and allowed to dry before you seal. Some surfaces may need a primer; if so, let the primer dry before applying the sealant.

How to apply it

1. Clean the surface so it is dry and free of dirt, grease, oil and water. Clean metal and glass with thinners or mineral turps and let them dry.
2. Prime if the substrate requires it, and allow the primer to dry first.
3. Fit backing material — use approved backing material for joints over 10mm deep.
4. Cut the nozzle at a 45 degree angle to the bead width you want.
5. Apply to the substrate with a sealant gun in a continuous bead, working it into the joint.
6. Tool the bead within 5 to 8 minutes. Skin time is 4 to 8 minutes, so this is not a step to leave until the end of the run.
7. Clean up excess before the sealant cures.

For a neat appearance, use masking tape and remove it before the sealant has skinned over.

Limitations — where Pro-Trade All Purpose should not be used

These are the manufacturer's stated limits:

• Not suitable for structural glazing.
• Not suitable for submerged joints where porous substrates permit water to the bond interface.
• Not suitable for aquarium construction.
• Not recommended for drinking water tanks.
• Should not be applied in contact with bituminous materials or some rubber products. These can contain components that migrate into the sealant, causing staining or reduced performance.
• Complete painting before applying the sealant — it cannot be successfully painted over.

The product page adds that it is not suitable for some plastics without testing, naming PE, PP and PTFE. A pre-test on an offcut is the cheap way to find out.

Of these, the paint limitation is the one that most often gets discovered too late, and the bituminous materials warning is the one that causes the least obvious damage — staining and reduced performance appear well after the job is finished.

Clean up and storage

Uncured sealant cleans up with mineral turpentine. Given a skin time of 4 to 8 minutes, clean up as you go rather than at the end.

Storage life is 12 months from the date of manufacture if stored below 28°C.

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.
• Eye irritation — Category 2A. H319: causes serious eye irritation.
• Flammable liquids — Category 4. H227: combustible liquid.

It is not classified as Dangerous Goods under the Australian Code for the Transport of Dangerous Goods by Road & Rail, or under New Zealand NZS5433.

What is in it

Chemical entity	CAS number	Proportion (w/w)
2-Butanone, O,O',O"-(methylsilylidyne)trioxime	22984-54-9	1–10%
N-[3-(Trimethoxysilyl)propyl]ethylenediamine	1760-24-3	<1%
Ingredients determined to be non-hazardous or below reporting limits	—	Balance

The butanone-oxime silane is the neutral cure system the page above describes. It reacts with moisture in the air and releases methyl ethyl ketoxime rather than acetic acid — no vinegar smell, and none of the corrosion problems an acetic-cure silicone brings to copper, zinc, concrete and mirror backing. It is also, on the evidence of the classification, what makes this a skin sensitiser: the oxime silanes are the only substantial declared component, and oxime chemistry is the component class that carries H317 across this whole family of neutral-cure sealants. Treat that attribution as informed inference rather than a sourced statement.

Category 1 skin sensitisation is the hazard to plan around, and it is not irritation. Irritation is a local reaction that clears once contact stops. Sensitisation is the immune system learning to react to the material: once acquired it is generally permanent, it is triggered thereafter by exposures far smaller than the one that caused it, and each later contact tends to be worse rather than milder. Critically, it develops from repeated everyday contact rather than one bad accident. This is a trade product — the name on the cartridge says so — and the person using it runs shower screens, baths, vanities and kitchens week in, week out, tooling each bead with a wet finger because that is the fastest way. That is the exposure pattern that produces sensitisation, and it is a genuine career risk, not a warning-label formality.

Wear gloves and tool with a spatula or a soapy finger inside a glove. If a rash appears after a day on the tools, especially one that comes up hours later, get it looked at and recorded rather than working through it.

The eye classification sits a step below the acetic-cure wet-area silicones: Category 2A serious eye irritation, which is reversible, where an acetic-cure product such as Fix & Go Bathroom & Kitchen carries Category 1 eye damage. H227 combustible is the mildest flammability class there is — the material burns if ignited but is undeclared for transport, and ordinary care around ignition sources covers it. The page above notes the product is not suitable for aquariums and not recommended for drinking water tanks; nothing in the safety data contradicts that, and the fungicide the product is sold on is a reason in its own right to keep it away from a tank you drink from.

Protection

• Gloves — the important one. 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 or goggles.
• Clothing — overalls and safety shoes.
• Ventilation — natural ventilation is adequate in normal use; avoid breathing vapours, and ventilate a small wet area while the bead cures.
• Wash hands before smoking, eating, drinking or using the toilet, and wash contaminated clothing before storing or re-using it.
• Storage — cool, dry, well-ventilated place out of direct sunlight, away from foodstuffs, incompatible materials and sources of heat or ignition. The page above adds: below 28°C, and 12 months from the date of manufacture.

First aid

Exposure	What to do
Skin	Remove contaminated clothing and flush the skin and hair with running water. If swelling, redness, blistering or irritation occurs — including hours later — seek medical assistance. A delayed reaction points to an allergic response rather than simple irritation.
Eyes	Hold the eyelids apart and flush the eyes continuously with running water. Keep flushing until the Poisons Information Centre or a doctor tells you to stop, or for at least 15 minutes, then get to a doctor or hospital.
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 Pro Trade All Purpose Silicone

How long do I have to tool the bead?

Tooling time is 5 to 8 minutes, and the skin forms at 4 to 8 minutes. Work in short sections.

When is it tack free?

Approximately one hour after application.

How long does it take to cure right through?

The cure rate is 10mm in 5 to 7 days, so it depends on the depth of the bead.

Can I paint over it?

No. The sealant cannot be successfully painted over — complete any painting before you apply it.

Will it corrode metal?

No. It is a neutral cure silicone and will not corrode metals, which is why it suits metal frames, powder coated surfaces and glazing hardware.

Will it stick to plastic?

It is suitable for most plastics, but pre-testing is recommended, and the product page notes it is not suitable for some plastics without testing, including PE, PP and PTFE.

Can I use it in an aquarium or a water tank?

No. It is not suitable for aquarium construction and is not recommended for drinking water tanks.

Can I use it on a submerged joint?

Not where porous substrates allow water to reach the bond interface. It is also excluded from structural glazing.

Is it mould resistant?

It contains a fungicide to prevent mould and mildew growth in hot and humid areas, which is what makes it appropriate for bathrooms and kitchens.

Does it meet green building VOC requirements?

Its VOC content is 30 g/L, within the GBCA limit of maximum 50 g/L. It is also BS 5889 approved.

How long can I keep it on the shelf?

12 months from the date of manufacture, stored below 28°C.

Is there a version specifically for wet areas or glass?

Yes — see Pro Trade Wet Area Silicone and Pro Trade Glass Silicone, or the full multi-purpose sealant range.