Best Epoxy For Plastic Radiator Repair 2023

A radiator is an essential part of the cooling process that keeps the car engine from overheating. Thus, a malfunctioning radiator can cause serious accidents including fire hazards and explosion.

Usually, the problem car owners face with the radiator is a leak or crack on its surface.

However, you don’t need to run to a mechanic every time you face a leak, specifically, if your car uses a plastic radiator. Because unlike a metal or aluminum radiator that can only be fixed by a fusion weld, plastic radiators can be fixed on your own using the right epoxy adhesive.

So, we decided to create this guide, which is designed to make sure you purchase nothing but the best epoxy for plastic radiator repair process. Our aim is to keep you and your vehicle safe through providing all the correct and necessary facts.

Top 6 Epoxy For Plastic Radiator Repair

1. J-B Weld, MarineWeld Marine Epoxy 8272

J-B Weld has held onto its reputed standard in this product, and that in itself says a lot.

The package contains 1 tube of resin and 1 tube of hardener, each containing 1-pound of material. It employs a dual part, cold welding process to create the bonding.

Cold welding delivers a similar strength of repair you’d get from a regular weld, except it doesn’t require any heating to create the bond. Thus, this product is an ideal choice for repairing plastic radiators, which are by nature sensitive to high temperature.

You’ll need to mix the epoxy resin and hardener in a 1:1 ratio, clean and roughen up the surface, and then apply the solution. The result is a dark grey layer, which offers a high Tensile strength and temperature tolerance.

According to the manufacturer, the product delivers a setting time between 4 to 6 hours. However, for a fully cured fix you should wait at least 24 hours.

The epoxy solution is designed to resist chemicals like petroleum, acid, etc. Therefore, it won’t react with the internal mechanism of the radiator. The product is strengthened by infusing steel particles so it can absorb and resist high impacts.

After properly cured, you can also drill and sand the surface.

Highlighted Features:

  • Applies a cold welding process to protect your radiator from heat.
  • Provides a steel particle infused product to improve impact absorption.
  • Resists chemicals that can interact with the radiator’s other elements.
  • Provides a 5020 PSI Tensile strength
  • Offers a temperature tolerance up to 287-degree Celsius.

2. PC Products, PC-Woody Wood Repair Epoxy Paste 16333

Quantity rarely meets quality. However, this product is a rare exception.

The package offers a combination of 2 jars, each containing 12-pounds of epoxy paste.

The product is water, weather, UV, rot, and chemical resistant. It has a score of 100 In/Ib in the Gardner Impact test, which is specifically conducted to determine the strength of a plastic surface.

The manufacturer uses a “Wet Grab” technology, which makes the bond waterproof once its cured. The feature also provides a high TFT (tack free time) to reduce dripping while the bond forms.

With a water absorption rate of less than 0.5 percent and a heat deflection rate of 48-degree Celsius, this paste is a perfect solution to fix a plastic radiator with safety and durability.

The epoxy paste is nontoxic after a full cure. It also produces a nonconductive bond, making the paste significantly eligible for repairing radiators along with other electronic accessories. 

In terms of applying, the product can withstand 35 to 115-degree Fahrenheit of heat. If you want to work on the cured surface, it is capable of surviving between a range of -20 to 200-degree Fahrenheit.

Highlighted Features:

  • Provides water, weather, UV, rot, and chemical resistance.
  • Creates a nonconductive bond to let you safely repair electronic accessories.
  • Uses a “Wet Grab” technology to eliminate dripping while bonding forms.
  • Certified by the Gardner Impact test, which ensures a strong plastic bond.
  • Offers a 48-degree Celsius heat deflection rate to contain shape under heat.

3. Permatex, PermaPoxy Multi-Metal Epoxy 84109

If you are tired of using separate tubes to prepare epoxy, Permatex presents an innovative solution.

The product is structured in a panel style, designed to hold and use a dual syringe system, along with a holding capacity of 25-milliliters.

Thus, the 1:1 ratio mix automatically comes out in equal proportions. However, you must be gentle with your push to avoid an imbalanced mix.

PermaPoxy uses a double part bonding system to adjoin rigid plastics like ABS, Polyester, and Hard Plastic.

It takes only 4 to 5 minutes for setting, without requiring you to enforce a clamping. The fixture time is 10 minutes. However, we recommend you wait at least 18 to 24 hours for a full cure.

Another feature that led us to consider this product as the best epoxy for plastic radiator fixing is its resistance to water, shrinking, and chemical elements such as solvents. It also provides a permanent strength up to 4500 PSI.

After a complete cure, the bonded surface can be drilled and sanded. The bonding can also withstand from -51 to 149-degree Celsius of heat.

Highlighted Features:

  • Applies a unique structure to ensure an easy mixing of the components.
  • Delivers a permanent strength of 4500 PSI, for superior shock absorption.
  • Offers resistance against water, shrinking, and chemical solvents.
  • Provides an external cap to protect the components from drying out.
  • Can be used on rigid plastics like ABS, Hard Plastic, etc.

4. Gorilla, Heavy Duty GorillaWeld Steel Bond Epoxy

“If a thing ain’t broke, don’t fix it.”

That is the approach Gorilla took with this product. The package follows a traditional, two-part epoxy system, delivering a tube of Epoxy resin and a tube of hardener.

Each tube contains 14.5-millimeters of liquid, delivering a total amount of 29.4-milliliters. The resin and hardener should be mixed in equal amounts to achieve full effect of the adhesive.

The mix takes about 10 minutes to half an hour for setting in. A full cure usually occurs within 24 hours, providing you a dark grey layer. We recommend cleaning the particular surfaces of the radiator before laying on the mix.

The product is effective on most plastic surfaces like ABS and Polyester. However, it may not be as functional on polypropylene and polyethylene.

The bond created has waterproof properties, which will enhance the level of protection for the fixed radiator. It also has a Tensile Strength score of 4250 PSI. Thus, a repair is unlikely to fall apart even under strong impact.

Once fully cured, the product can withstand temperatures ranging from -40 to 300-degree Fahrenheit.

Such a wide range of temperature tolerance makes this product the best epoxy for plastic radiator repair, as the machine needs to manage constant transmission of heat.

Highlighted Features:

  • Provides a 4250 PSI Tensile Strength to provide superior shock resistance.
  • Offers a high temperature tolerance to repair easily heated machines.
  • Effective on most plastic surfaces like ABS and Polyester.
  • Provides a waterproof bonding, to increase the level of protection.
  • Features one of the strongest bonding system for structural maintenance.

5. K Tool International, Q Bond Adhesive Kit KTI90002

Different is good, if it works.

And this kit does, we can certainly tell you that.

The Q-BOND package offers a pair of bottles, each containing 10-milliliters of cyanoacrylate adhesive. It also contains a pair of reinforcers.

The black container holds powdered reinforcer, designed to apply on plastic surfaces. And the grey container provides reinforcer for metal surfaces, which can also be used on grey plastics to achieve a color synced repair.

Though not technically an epoxy, the product can be extremely effective to bond plastic surfaces. The powder is used as base, which is then steeped with the glue to trigger a chemical reaction, creating a repair surface that mimics the properties of plastic.

When you apply the mix to fix for example, a leak on the radiator, it is able to create a bond far more tolerant of impact and heat than a regular super glue, and as effective as an epoxy.

Since Plastic radiators constantly manage a high amount of heat transmission, the impact resistant and temperature tolerant bonding provided by the product is important to fix these machines.

Highlighted Features:

  • Specifically designed to perform plastic to plastic bonding.
  • Provides a longer repair time window than epoxy to increase flexibility.
  • Offers a setting time of only 10 to 15 seconds.
  • Mimics a plastic surface, while offering higher impact and heat tolerance.
  • Can be used for multiple repair purposes.

6. RapidFix, UV Liquid Plastic Adhesive Twin Pack, 6121830ES

Let’s imagine a scenario:

You prepare an epoxy mix to fix a crack on your car’s radiator and suddenly the phone rings. Then when you return to the worksite, the mix has become dried and unusable.

Well, we’ve added this product to the list to solve that specific issue.

The package offers 2 bottles, each containing 10-mililliters of adhesive activated by UV-light. The liquid adhesive, particularly manufactured to bond plastic surfaces, only produces a solid bond when triggered by UV. Thus, you don’t need to struggle with a particular time frame between which the repair must be completed.

According to RapidFix, the setting process takes no more than 15 to 30 seconds. This feature allows you to perform quick fixes on your radiator while providing an unconstrained time limit to properly assemble the surfaces you intend to bond. 

The adhesive provides a clear dry feature, allowing a traceless fixing job. Once fully cured, you can paint, sand, and drill the repaired surface as well. The container is protected by a multi-layered screw cap system, which prevents the adhesive from auto evaporation.

Highlighted Features:

  • Provides an unconstrained time frame to complete the repair.
  • Offers a clear dry feature to allow a traceless fixing job.
  • Setting process takes only 15 to 30 seconds, to allow performing quick fixes.
  • Features a multi-layered screw cap system to prevent auto evaporation.
  • Repaired surface can be painted, sanded, and drilled after a full cure.

How To Choose The Right Epoxy For Plastic Radiator Repair

1. Range Of Temperature Tolerance

The range of temperature tolerance is crucial when it comes to choosing the right epoxy for repairing your plastic radiator. Since a radiator is constantly going through a transmission of high temperature, an epoxy with a lower temperature tolerance can melt or bend, causing a potentially life threatening fire hazard.

We recommend choosing an epoxy that provides a wide range of temperature tolerance. For example, the PC-Woody Epoxy paste, which can withstand -20 to 200-degrre Fahrenheit, or the GorillaWeld epoxy, which can function from -40 to 300-degree Fahrenheit.

2. Bonding Surface

Not all epoxy adhesives are designed to create plastic to plastic bonding. Thus, you should check the product description to ensure that the epoxy is compatible with plastic surfaces, such as ABS, Polystyrene, Hard Plastics etc.

Some epoxy adhesives create a bonding layer that mimics the properties of plastic. For example, the Q-bond adhesive kit creates a repair layer that offers strong resemblance to a plastic surface, along with a much higher impact and heat tolerance.

We recommend keeping these factors in mind at the time of purchase to ensure you get the finest possible quality of repair out of your epoxy.

3. Bonding Strength

Bonding strength determines how much impact the repaired surface can withstand. You can look at some particular data to discerns this factor. For example, the Tensile Strength score, Flexural test score, Gardner Impact Test score, etc. of a bonding can tell you about its capability to resist and absorb impact.

We recommend purchasing an epoxy that has scored high in these tests, as this is a surefire way to determine you’re purchasing the best epoxy for radiator repair available in the market.

Otherwise, the repaired layer’s bonding may break under pressure and can cause serious accidents. You should specifically look at the Gardner Impact Test score, as it exclusively determines the impact resistance capability of a plastic surface.

3. Water And Chemical Resistance

We recommend buying an epoxy that is designed to resist water and chemicals (e.g. solvents, acid, etc.) to ensure a safe repair.

A waterproof or water resistant epoxy will ensure that the repaired layer won’t fall apart if it faces a wet situation.

A radiator often contains certain chemicals such as battery acid and various types of coolants. If you use an epoxy that doesn’t resist these chemicals, the repaired layer may interact with those elements, which can cause a fire hazard.

4. Set, Fixture, And Cure Time

Different types of epoxy adhesives provide different set, fixture, and cure time. It is important to buy an epoxy that balances these factors to your benefit.

We recommend buying an epoxy that provides a flexible setting time, which would allow you to control as well as fix mistakes during the setting process (e.g. wrong positioning of the repaired surface, inaccurate assembly of parts, etc.).

Also, ensure that the epoxy provides a quick fixture and cure time. This would eliminate waiting long hours till the repaired layer is ready to function and can be operated on.

5. Structure Of Application

Epoxy adhesives mainly fall into two categories:

A. Single step epoxy that doesn’t require you to mix the resin and hardener and can be applied directly. 

B. Double step epoxy, which provides resin and hardener in separate containers, and need to be mixed on your own for application.

We recommend purchasing an epoxy that uses a double step application process. This will give you more control over the mix and choose the ratio of components in it. It’ll also allow you to experiment with the mixed solution, allowing you to prepare a mix best suited to your needs.

Final Words

We often look over the check engine light and simply keep on driving. However, this seemingly mild negligence can end up in a sorrowful tragedy.

One of the biggest issues behind automobile accidents is a leaky radiator, which can cause the engine to overheat or create a chemical fusion that leads to an explosion. This is why choosing the best epoxy for plastic radiator repair is so important.

Because, if you fix a leak with an ineligible epoxy adhesive, you may face problems despite taking the right measures.

Remember, safety is priceless but only when it’s done right.

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