10 Best Radiator Leak Repair Putty in The UK

Last updated on 12/08/2025

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Holts SEALit Leak Repair 250ml - Professional Radiator & Coolant Leak Sealer for Engine, Cylinder Head, Head Gasket, Freeze Plugs, Water Pump Gaskets, Radiators Red - 1 Pack 250ml

Why We Love It

Quick and permanent leak seal.
Easy to use and effective.
Safety for engine components ensured.

Main Highlights

Professional Leak Repair: Seals leaks in engine blocks, cylinder heads, head gaskets, freeze plugs, and water pump gaskets quickly and permanently.
Easy Pour-and-Go Formula: No draining or flushing required—simply pour into the radiator or expansion tank for instant results.
Safe and Non-Clogging: Specially designed to work without clogging or damaging your engine, radiator, or cooling system components.
Corrosion Protection: Provides long-term protection against rust and corrosion, extending the life of your cooling system.
Compatible with All Coolants: Works with all types of coolant and antifreeze. One 250ml bottle treats up to 21 liters of coolant capacity.

Fast fixes for emergencies.
No tools needed.
Weatherproof and corrosion resistant.

Main Highlights

FAST FIX EPOXY PUTTY: Waterproof repair for leaking water lines and other plumbing problems (cures in approx 60 minutes)
REPAIR & REBUILD: Repairs, rebuilds and seals copper and metal fittings fast.
IDEAL FOR PLUMBING EMERGENCIES: Frozen or split pipes, leaking joints and seals, etc
EASY MOULD: Putty-like consistency, easy to mould and shape as needed
HAND MIX: Mix, shape and apply by hand, no tools required
FAST CURE: Functional cure in 60 mins, fully waterproof, can be drilled, sawn, sanded, filed, tapped, machined, and painted
WEATHER PROOF & RESISTANT TO CORROSION: Resistant to water, chemicals and temperature extremes

J-B Weld 2120 Radiator Repair Kit

Why We Love It

Professional quality, permanent repairs.
Simple and easy instructions.
Versatile for multiple applications.

Main Highlights

RADIATORWELD: Our radiator and plastic tank repair kit has all you need for making professional quality, permanent repairs with state of the art components and easy to follow instructions.
COUNT ON US: For more than 40 years, our products have earned a loyal following from people who take pride in their work. With each product we innovate, we continue to provide the world's strongest bond for your projects.
SIMPLE TO USE: No removal of tank or radiator is required to stop leaks. Easily fix holes up to 3/8" diam. or cracks up to 4" long. Includes epoxy putty, fiberglass cloth, sandpaper, and applicator.
VERSATILE & DEPENDABLE: Great for radiators, washer fluid tanks, storage tanks, water tanks, plastics, composites, PVC and more. Professionals, mechanics and avid DIYers know J-B gets the job done.
NO PROJECT TOO BIG OR TOO SMALL: We have all the products you need to get the job done right. JB Weld always delivers the legendary performance of the World's Strongest Bond.

K-Seal Coolant Leak, 236ml | Multi-use Car Radiator & Head Gasket Repair Sealant

5% OffFree Shipping

Why We Love It

No messy flushing required.
Easy and permanent solution.
Compatible with any antifreeze.

Main Highlights

FIX IT FAST: Our multi-purpose solution works in minutes to quickly & permanently seal leaks in the radiator, head gasket, freeze plugs, block, heater matrix & water pump. Fixes most leaks in water-cooled engines.
STOP HOLES & CRACKS: With just 1 step our unique formula will seek out each hole & crack, permanently sealing them, without any adverse impact on the efficiency of your engine cooling.
EASY TO USE: K-Seal couldn't be simpler to use & requires no draining or flushing; just shake, pour & go - shake the bottle, add the fluid to your coolant system & run your engine as normal.
VERSATILE COMPATIBILITY: Compatible with all types of antifreeze coolant. Suitable for use in both cars & light trucks with up to 12 cylinders. A permanent repair for the lifetime of the engine.
PROFESSIONAL-GRADE RELIABILITY: Trusted by mechanics, our sealer delivers a durable & long-lasting repair. A cost-effective solution to engine coolant leaks, enhancing the reliability & performance of your vehicle’s cooling system. We've sold millions worldwide & are independently verified by university testing to meet ASTM D3147.

Domestic Radiator Epoxy Repair Putty Kit - Repairs Chips, Cracks, Leaks & Similar Damage to Enamel, Steel, Brass, Cast Iron Radiators. (White)

Why We Love It

Heat resistant up to 130C.
Waterproof and cleaner resistant.
Gloss finish with Lacquer.

Main Highlights

This kit is specifically formulated for repairing chips, cracks, leaks and similar damage to Enamel, Steel, Brass, Cast Iron domestic radiators
The putty is fully waterproof and has outstanding resistance to all household cleaners whilst being heat resistant up to 130C.
The Acrylic Lacquer Clear dries Crystal Clear to give the repair a Gloss finish.
This product will repair damage up to: 4cm Long, 4.5cm Wide & 3cm Deep.
This Kit Contains: 1 x 38g Epoxy repair Putty (Part A & Part B) 1 x Application Spatula 1 x Wet & Dry Sanding Paper 1 x 10ml Acrylic Lacquer Anthracite Grey 1 x Instruction Leaflet

Satin Anthracite/Dark Grey Domestic Radiator Epoxy Repair Putty Kit - Repairs Chips, Cracks, Leaks & Similar Damage to Enamel, Steel, Brass, Cast Iron Radiators.

Why We Love It

Outstanding resistance to cleaners.
Fully waterproof, heat resistant.
Repairs chips, cracks, leaks.

Main Highlights

This kit is specifically formulated for repairing chips, cracks, leaks and similar damage to Enamel, Steel, Brass, Cast Iron domestic radiators.
The putty is fully waterproof and has outstanding resistance to all household cleaners whilst being heat resistant up to 130C.
The Acrylic Lacquer Anthracite Grey/Dark Grey dries to give the repair a Satin finish.
This product will repair damage up to: 4cm Long, 4.5cm Wide & 3cm Deep.
This Kit Contains: 1 x 38g Epoxy repair Putty (Part A & Part B) 1 x Application Spatula 1 x Wet & Dry Sanding Paper 1 x 10ml Acrylic Lacquer Anthracite Grey 1 x Instruction Leaflet

VIKEYTIM Epoxy Putty, 120g Quick Leak Repair Epoxy Putty Plastic, Ceramic, Acrylic, Metal, Stone, Wood, Glass Bonding and Repair Putty Stick (White)

Free Shipping

Why We Love It

Strong, permanent and versatile repairs.
Withstands extreme temperatures.
Easy and efficient usage.

Main Highlights

High Strength Plastic Epoxy Putty: Forms a hard surface when fully cured, providing a hard permanent restoration. Heat, corrosion, and water resistant, it won't shrink or crack
2 Parts Epoxy Putty is Versatile: Bonds and repairs hard plastic, metal, stone, ceramic, wood, glass, acrylic, sculpture and more. Can be sanded, painted, drilled after fully cured
Steps For Epoxy Putty White: Knead two parts of epoxy putty according to the ratio of 1:1 until the color is the same, and there will be slight heat at this time. Then stick to the position that needs to be repaired, and press firmly. Preliminary curing in 1 hour, complete curing in 24 hours
Epoxy Putty Stick Characteristics: Completely mixed evenly, the color is WHITE, and the temperature range is - 50°C to 120 °C. Can be used to glue, fill, and repair most items, providing long-lasting and effective repairs
Epoxy Steel Putty: Plastic putty is composed of epoxy resin and hardener, which has strong adhesion and strong surface. If you encounter problems during use, you can contact us through amazon as soon as possible to provide you with professional solutions

S/S Permatex® - Fuel & Radiator Repair Kit - Putty for Metal Tanks #09116

Why We Love It

Quick and easy repairs.
Reliable and durable materials.
Cost-effective solution always.

Main Highlights

fuel tank repair
radiator repair kit
Permatex 09116

Car Radiator & Hose Stop Leak Repair Additive Anti Corrosion 250ml Repairs Weld Cooling System Rads

Why We Love It

Permanently seals radiator leaks.
Works with anti-freeze.
Contains rust inhibitors.

Main Highlights

Permanently seals radiator leaks radweld k seal
Unaffected by anti-freeze
Contains rust inhibitors
Stops leaks in radiators and hoses
WILL BE SEND OUT SAME WORKING DAY IF ORDER PLACED BEFORE 2PM. YOU WILL RECEIVE IT NEXT WORKING DAY

EVO-STIK Plumber's Mait Quick Leak Repair Putty, Instant Repairs for Pipes, Radiators, Tanks & Cylinders, Waterproof, 50g

Free Shipping

Why We Love It

Strong and waterproof for durability.
Resistant to high temperatures.
Easy application and customization.

Main Highlights

Strong, waterproof and fast setting epoxy putty designed for long lasting emergency plumbing repairs to leaking pipes, radiators, tanks and cylinders
Can be applied to damp or wet surfaces, Waterproof and chemical resistant, Resists temperatures up to +150°C
Easy to apply - when dried it can be drilled, sanded, machined and painted
Ideal for bonding to copper, brass, steel, aluminium, fibre glass, acrylic and porcelain
Contents: 1x EVO-STIK Plumber's Mait Quick Leak Repair Putty, 50g

8.7

Excellent

We scanned 689 products

We reviewed these offers relevant to the Radiator Leak Repair Putty within online retailers such as Amazon, eBay and other local retailers, ensuring we covered all major brands and models. The products we selected come from trusted brands like HOCHSTE, JENOLITE, J-B Weld, K-Seal, ED Supplies, VIKEYTIM, Permatex, Generic, EVO-STIK, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.

For the best Radiator Leak Repair Putty in the market, we considered we took a deep dive into 3446 online reviews , focusing on elements like user satisfaction, performance in real-world conditions, and long-term reliability. Our ranking also evaluates each review’s relevancy, authenticity, up-to-dateness and depth so that the comparison is more sound.

We concluded that:

The clear winner of our analysis is Holts SEALit Leak Repair 250ml - Professional Radiator & Coolant Leak Sealer for Engine, Cylinder Head, Head Gasket, Freeze Plugs, Water Pump Gaskets, Radiators Red - 1 Pack 250ml. We love many things about this product by HOCHSTE. What sets it apart from the competition is Quick and permanent leak seal. , Easy to use and effective. , Safety for engine components ensured. .
The best value product for most shoppers and where user satisfaction is continuously the highest is JENOLITE Epoxy Putty Repair Stick | COPPER | Copper Pipe & Tank Repair | Ideal For Plumbing Emergencies | Repair Leaking Hot Lines & Other Plumbing Issues | 112g (7 Inches) by JENOLITE based on online reviews by bloggers, experts and online shoppers.
The biggest bargain at the moment for Radiator Leak Repair Putty and the best cost-to-value ratio is K-Seal Coolant Leak, 236ml | Multi-use Car Radiator & Head Gasket Repair Sealantat K-Seal with a 5% discount.
Our list of the best Radiator Leak Repair Putty is updated regularly to reflect new releases and changes in product availability, so be sure to check back often for the latest rankings and discounts.

10 Best Radiator Leak Repair Putty in The UK

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We scanned 689 products

We concluded that: