What is Selleys Knead It Aqua, and where should you use it?

Selleys Knead It Aqua is a hand kneadable, fast setting, co-extruded epoxy repair system — a two-part putty supplied as a single stick that you cut, knead together and press into the repair. It can be used on a wide range of materials, and the thing that sets it apart from the rest of the Knead It family is where it works: it is especially suitable for application to damp, wet or underwater substrates.

That is the reason to choose it. Most repair adhesives need a dry, prepared surface, which rules them out of exactly the situations that produce urgent repairs — a weeping pipe joint, a leaking tank, a fitting you cannot get dry because it is the thing that is leaking. Knead It Aqua is designed to be applied to a surface that is damp, wet or submerged, and it will not sag, run or drip while it sets.

Key properties

• Designed for wet and underwater repairs, and suitable for damp, wet or submerged surfaces
• Heat resistant to 120°C continuous
• Will not sag, run or drip
• Can be drilled, sanded and painted after cure
• Suitable for some plastics — but not PE or PP

Working time, set and cure

Selleys lists three timings for Knead It Aqua, in ascending order: approximately 20–30 minutes, approximately 60 minutes, and approximately 24 hours. Read alongside the directions — apply within the working time, and allow full cure before machining or painting — the shortest figure is the window in which the kneaded putty can still be worked and shaped, the middle figure is the set, and the 24 hours is the full cure to reach before you drill, sand or paint it.

The practical consequence of a 20–30 minute working window is that you cut and knead only what you need for the repair in front of you, and you do it once you are ready to apply, not before. Once mixing starts, the clock is running.

The other timing note matters in a cold plumbing cupboard or an outdoor tank repair in winter: set time increases below 20°C. A repair that would be firm in an hour on a summer afternoon may take considerably longer in a cold subfloor, and that is a reason to wait rather than to test it early.

Heat resistance to 120°C continuous is the other figure worth planning around. It is a continuous rating rather than a peak, and it is what makes the product usable on warm-water services — but it is not a licence to use it on anything hot.

How to apply it

Preparation is short but not optional: roughen the surface for best adhesion. An epoxy putty grips a keyed surface far better than a smooth one, and on a wet repair that mechanical key is doing more of the work than usual.

1. Cut the required amount from the stick.
2. Knead until you have a uniform colour. Ensure the putty and hardener are properly mixed — Knead It becomes warm as it is mixed, so a uniform colour plus a mild heat radiating from the putty is the sign it is ready.
3. Apply within the working time — approximately 20–30 minutes.
4. Press firmly into the repair area.
5. Smooth before hardening.
6. Allow full cure before machining or painting.

The mixing step is where this product most often fails, and it fails invisibly. A stick with streaks of unmixed hardener still visible has patches that will never cure properly, and you will not find out until the repair is under pressure. Knead until the colour is uniform throughout — not nearly uniform — and use the warmth as the confirmation that the reaction has actually started.

Limitations — where Knead It Aqua should not be used

• Does not adhere to polyethylene, polypropylene or PTFE. These are the plastics an epoxy cannot grip, and a great deal of domestic plumbing and tankware is made from them. Identify the material before you start.
• Not suitable for flexible joints. The cured putty is rigid; a joint that flexes will break the bond or the repair.
• Heat resistance is 120°C continuous — do not use it above that.

The plastics limitation deserves the emphasis. "Some plastics" are suitable, but polyethylene and polypropylene are extremely common in water storage and irrigation fittings, and they are precisely the parts most likely to be leaking. If the item is PE or PP, no amount of surface preparation will make this repair hold.

Finishing the repair

Once fully cured, Knead It Aqua can be drilled, sanded and painted. That makes it useful for repairs that need to be reshaped or made invisible afterwards, rather than just sealed — but every one of those operations belongs after the full cure, not after the set.

Safety information

Selleys does not publish a safety data sheet for Knead It Aqua in the sources used to build this page, so no GHS hazard classification, signal word or hazard statements are reproduced here.

That is an absence of published data, not a finding that the product is non-hazardous. It should not be read as an all-clear, and the classification of a similar or neighbouring product should not be assumed to apply — variants within a Selleys range frequently carry genuinely different classifications.

A product data sheet is published but no safety data sheet. Note that the AS/NZS 4020 drinking-water compliance described elsewhere on this page is separately documented and is not affected by the absence of an SDS.

To obtain it, request the safety data sheet for this product from Selleys directly: 1300 555 205 in Australia, 0800 735 539 in New Zealand, or contact Selleys. For an emergency involving a Selleys product the emergency line is 1800 220 770 in Australia and 0800 220 770 in New Zealand; for suspected poisoning, the Poisons Information Centre is 131 126 in Australia and 0800 764 766 in New Zealand.

Common questions about Selleys Knead It Aqua

Can I really apply it underwater?

Yes. It is designed for wet and underwater repairs and is suitable for damp, wet or submerged surfaces.

How long do I have to work with it once it is mixed?

Approximately 20–30 minutes. Cut and knead only what you need, and only when you are ready to apply it.

How do I know it is mixed properly?

By colour and by heat. Knead until the colour is uniform, and expect the putty to become warm — a mild heat radiating from it is a good indication the two parts have combined.

When can I drill or paint the repair?

After full cure, which is approximately 24 hours.

Does the cold affect it?

Yes. Set time increases below 20°C, so allow longer in cold conditions.

How hot can the repair get?

It is heat resistant to 120°C continuous.

Will it stick to plastic pipe?

It is suitable for some plastics, but it does not adhere to polyethylene, polypropylene or PTFE. Check what the item is made from first.

Can I use it on a joint that moves?

No. It is not suitable for flexible joints.

Do I need to prepare the surface?

Roughen the surface for best adhesion. That mechanical key is doing a lot of the work, particularly on a wet repair.

Will it run out of an overhead repair?

No. It will not sag, run or drip.

Can I shape it after applying?

Yes — press it firmly into the repair area and smooth it before hardening. After that, shaping waits for full cure and a tool.

Which Knead It should I use if the surface is dry?

Aqua is the variant specified for damp, wet and underwater work. The other variants in the Knead It family are made for other conditions and substrates.

The other epoxy putties in the range are listed under specialist fillers and putty — including Knead It Multi Purpose, Knead It Steel and Knead It Auto Fix.